• 455 Martinson, Los Angeles
  • 8 (043) 567 - 89 - 30
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  • Koch, Huxhold & Hannemann (KHH) - made surprising System Korte slide rule that does addition & subtraction
  • Smallwood Folding Shoe Sizing Stick in metric for French shoe sizes 10-48 in increments of a Paris point (⅔ cm)
  • Lawrence MIT Antenna slide rule for radar antenna performance was classified during WWII by UK & US governments
  • ALRO-made ruler unusually with a cursor for analysing ECG printouts of the cardiac Sinus Rhythms
  • Hatters Gauge - for measuring the size of a hat but unusually calibrated in metric & imperial
  • Glovers Rule - for measuring the length of a glove in imperial inches
  • Unusual non-logarithmic QR 41 military model by Dennert & Pape (D&P) for training anti-aircraft gunners
  • Colour combinations slide rule made by German WH-Wohnen for Interior Designers
  • Professor Fuller’s Drum Calculator from 1878 - made by W.F. Stanley
  • Modern wristwatch with slide rule bezel calculator made by German maker Kienzle
  • Ruxton made Multi-Vider combined drop-lead pencil & slide rule
  • Rare Otis King Model N for Retail & Monetary with white scales (422 & 424) on a black background
  • Darnley’s Rotable Lightning Calculator/Pencil Case calculating aid
  • Makeba made Kombinator combination pencil & slide rule
  • Rare Carbic-made Fischer Calculator slide rule
  • Specialist slide rule for a national home cable radio broadcasting system offered in The Netherlands from 1930 to1970
  • Smallest drum (≈ 2.4m) made by renowned Swiss maker LOGA

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Browse all slide rules

Click on any Model in the list for its full specification/details OR hover over its "Thumbnail" (if shown) for a pop-up enlargements:
A.W. Faber
ModelTypeCommentsThumbnail
(350)Enhanced Mannheim

pre-runner to model 350 - cm scale in well of stock + INCHES to METER printed conversion scale on back


(364) Enhanced Mannheim

pre-runner to model 364 + cm scale in well + table of constants & 2 cursor windows in back


(368)Electro

pre-runner to model 368 & possibly first electro model by mainstream maker + V & W scales in well of stock + cm scale reversed + top & bottom edges bevelled


308Pocket Enhanced Mannheim
308/SPocket Enhanced Mannheim

promotional rule for: Osnabrücker Kupfer- und Drachtwerk


332Pocket Mannheim

promotional rule for: La Ceramique Nationale


339Mannheim

“Made in Bavaria” on back


368 (ver. 2)Electro

V & W scales, DR Patent 206428 & DRGM 271169 & 247514 in well of stock + top & bottom edges bevelled


373Lilliput Mannheim

inch scale on back


380Desktop Enhanced Mannheim

Gold lettering + cm scale in well of stock - INCHES to METER printed conversion scale on back


51/39/339School Mannheim

Interim follow-on version of 339 before 51/39 came out 


51/87Rietz
51/91School Enhanced Mannheim

“Import” stamped in back


51/91/309School Enhanced Mannheim

Interim follow-on version of 309 before 51/91 came out


52/22School Business

many gauge marks above top DF scale


52/39Mannheim

unbranded but MARABU advertising logo (= reseller Marabuwerke AG, Tamm) printed on back


52/39/355School Mannheim

cursor possibly not original


57/22School Business
Bitzer KuelmaschinenbauPocket Refrigerant

Special commission for Bitzer Kuelmaschinenbau GMBH (still operating) - 1 of only 2 such Faber/F-C made SR’s with no slide - possible forerunner & inspiration for later Danfoss made models


A.W. Faber-Castell
ModelTypeCommentsThumbnail

1/22Business - early

Pre 1958 version with 2-part British currency bottom edge scale (later combined scale) - table of conversion factors on back


1/22Business - latePost 1958 version with combined British currency scale
1/22Business - late exportPost 1958 export (inch edge scale) version with combined British currency scale
1/22ABusiness Addiator

British pre-decimal £sd bottom edge scales - conversion tables + Addiator on back


1/27Technical/Business

Only one its type made by F-C + instructions/table of constants on back & 2 cursor windows ​


1/28Super Business - late

Post 1958 version with combined British currency scale


1/44 EKAGNOSTCardiology - System Dr. Sandera

German Registered Design (DBGM 1614435) by Dr. Robert Sandera to help cardiologists analyse printed electrocardiographs (ECG’s) from electrocardiogram machines of the day - innovative & clever reuse of Rietz-like scales - K.17 table of conversion factors + ECG correction formulas & constants on back - read more ...


1/48Machining - System Dr. Winkel
1/54 (ver. 1)Darmstadt
1/54 (ver. 2)Darmstadtscale annotations + extra peripheral hairlines compared with ver. 1
1/54mDarmstadt

Origin of model suffix m unknown


1/60Enhanced Mannheim
1/60/360Enhanced Mannheim
1/77System Pickworth-likeUncommon model - cm scale in well of stock + conversion table on back + scale layout similar to 377 except K scale is not in back of stock but full-length on bottom edge
1/78/378Electrohand-drawn K scale on stock + V & W scales in well of stock
1/87 (ver. 2)Rietz

cm scale in well of stock


1/87 (ver. 3)Rietz
1/87/387Rietz
1/87ARietz Addiatior

conversion tables + Addiator on back


1/87mRietz

cm scale in well of stock - origin of model suffix m unknown


1/92Log-Log
1/94Rietz "Kiel"

​Tables of conversion factors & 2 cursor windows in back + "Kiel" = maritime centre in Northern Germany & local retailer Johannes W. Janssen was known as a major outlet for slide rules to the local navy clientele - see also Nestler 20/1 Kiel  


1/98 (ver. 1)ElectroV & W scales in well of stock
1/98 (ver. 2)Electro

V & W scales in well of stock


1/98/398Electro

V & W scales in well of stock


11/54Darmstadt
11/98ElectroV & W scales in well of stock
111/22Business

Two-part British pre-decimal currency scales


111/38 Stadia Topography - 400g
111/54DarmstadtOriginal version without the later extra BI & ST scales
111/54Darmstadt - late

Late model with extra BI & ST scales


111/54ADarmstadt Addiator - late

Late model with extra BI & ST scales - Addiator on back


111/66 (ver. 1) DEMEGRAPHPrinting - System Schirmer

For graphic design & follow-on replacement (converted DEMEGRPAH system & extra standard scales) for 2/66 - see also 20/66 SL typometer accessory for typewriter spacing


111/87Rietz
111/87ARietz Addiatior

Addiator on back


111/98Electro

Unusually the V & W scales are not in well but on front face.  ​


12/82Technical/Log-Log Export

Only model in the series = inexpensive school version of 2/83N


152/81Technical two-tone
152/82 (ver. CH)School D-Stab

red & white insted of green & white colouring + MADE IN SWITZERLAND version


157/87School Rietz
157/87School Rietz - blackmonochorme (black) version
157/89Log-Log
157/89Log-Log - black

monochorme (black) version


2/62Extra long Reinforced Concrete - System Dywidag
2/66 DEMEGRAPH 13Printing - System Schirmer

Expensive  (not a commercial success) model for graphical work according to a patented design (DE804932) by Max Schirmer + uncommonly wide body to accommodate the likes of vertical typographical scales on back + introduced with 20/66 typometer accessory & predecessor to 111/66


2/82Technical/Log-Log

See also later 2/82N sibling


2/82NTechnical/Log-Log

​See also earlier 2/82 sibling - model suffix N denotes new/advanced variant


2/83Technical/Log-Log long-scale

Green plastic rather than steel end-braces


2/83NTechnical/Log-Log long-scale

Impressive 30+ scales including a unique combined D & LL0 scale - model suffix N denotes new/advanced variant


2/84Mathema Hyperbolic

Designed by Dr. Eugen Moeller & only hyperbolic model F-C made + unusually extra gauge points placed on side edges of cursor


20/45 Bio-RhythmographBiology

For calculating biorhythms (rhythmic physical, emotional & intellectual cycles) - popular 1970s pseudoscience developed by German Wilhelm Fliess based on individual’s date of birth + mechanism cleverly built into model 2/83 style plastic box


20/66 DEMEGRAPHTypometer printing

Didot 6-14 point print system accessory introduced with 2/66 DEMEGRAPH 13


20/66 SL DEMEGRAPHTypometer printing

Didot 6-14 point print system accessory to F-C 111/66 System Schirmer - model suffix SL denotes German Schreibmschine Laeufer


20/68 ParifixConversion

slide rule style but a conversion table with cursor 


20/70Universal/Technical

Copyrighted design targeting fuel economy by Dieter von Jezierski while director of F-C in attempt to stall F-C’s waning interest in producing slide rules


3/11Desktop Structural Engineering

special tables on back


3/31Desktop Reinforced Concrete

Nomogram on slide and scales in well of stock


300586 S WaldnerPocket Notepad Wallet Rietz (67/87)

Wallet black (= suffix S for “Schwarz” to model no.) on the outside but grey on the inside - most wallets, etc were promotional company branded gifts e.g. for German laboratory & science classroom supplier: Waldner


310/52Demonstration OHP School D-stab/Log-Log

Overhead projector version for model 52/82


310/87Demonstration OHP School Rietz

Generic overhead projector version for Rietz models


310/88,89Demonstration OHP School Rietz-N/Log-Log

Overhead projector version for models 57/88 & 57/89


334/52Demonstration School D-Stab/Log-Log

Classroom version of model 52/82


334/87Demonstration Rietz

Classroom version for all models with Rietz scale layout


342 (ver. 2)Desktop Columbus Business long-scale - System Rohrberg

Co-branded (box & rule) with KLAWUN + 1st F-C specialist rule for Merchants - extra wide body


344Rietz-like

​cm scale in well + table of constants & 2 cursor windows in back


360 (ver. 1)Enhanced Mannheim

Railway track scales


360 (ver. 1)Enhanced Mannheim - earlyRailway track scales + cm scale in well of stock
360 (ver. 2)Enhanced Mannheim
360 (ver. 3)Enhanced Mannheim

wider cursor than other 360s


361Mannheim (double bevelled-edged)

cm scale reversed + top & bottom edges bevelled - read more ...


361 (ver. 1)MannheimRailway track scales
361 (ver. 2)Mannheim
363Enhanced Mannheimcm scale in well of stock + MADE IN BAVARIA on both box & stock
367Enhanced Mannheim

No cm scale in well of stock - metal strips


369Pocket Enhanced Mannheim

Two open windows with cursor line in back


375 (ver. 1)RietzRailway track scales
375 (ver. 2)Rietz
378Electro

V & W scales in well of stock


379Pocket Electro

V (coloured red) & W scales in well of stock + no “W” gauge mark + electro conversion table on back - see earlier sibling here ...


379Pocket Electro - early

V & W scales in well of stock + electro conversion table on back - see later sibling here ...


385NDesktop Rietz

Popular desktop model + table on constants & 2 cursor windows in back ​


387Rietzcm scale in well of stock
389Lilliput Enhanced Mannheim

2 cursor windows in back


392Log-Log

“Made in Bavaria” + table of conversion factors on back on back


398Electro

V & W scales in well of stock + short temperature scale on B


4/22Desktop Business

Cursor not shown in image - conversion table on back


4/38Desktop Stadia Topography - 360g
4/54Desktop Darmstadt

No blind date stamp - coversion tables & factors on a plastic book-mark


4/54Desktop Darmstadt - earlyConversion tables & factors on back
4/60Desktop Enhanced Mannheim

6 slide tension adjustment screws in bottom edge + table of conversion factors on back with 2 cursor windows


4/87Desktop Rietz
4/92/382Desktop Log-Log

3-digit model no. suffix was added as the 3/xx series transitioned into the 4/xx series + 6 slide tension adjustment screws in bottom side edge + table of conversion factors on back with 2 cursor windows


4/98Desktop Electro

V & W scales in well of stock


44/87Desktop Rietz

Part of unusual limited series made from high pressure laminated (HPL) wood with metal inserts - patent no. DE892693


52/80Mentor two-tone
52/81Technical
52/81 (ver. CH)Technical

MADE IN SWITZERLAND version


52/82School D-Stab/Log-Log

No BI scale - possibly an interim scale layout​


52/82School D-Stab/Log-Log - early

Extra BI, LL1, S’ & P scales only added to an later (?) version


52/82 (ver. CH)School D-Stab/Log-Log

MADE IN SWITZERLAND version with extra BI scale


57/22School Business two-tone​
57/22WPipe Flow

Special commission for Spanish company Fibrotubo for calculating the flow in asbestos-cement pipes but unusually has a standard F-C model number in the 5x/xx series but significance of W model number suffix unknown + design probably by Fibrotubo + formulas on back


57/67 (ver. 2)Philips - meteorology (dew point & humidity)

Unmarked - Philips no.: Z9.151.98


57/69Central Heating Capacity

Patented design (NL81186) for calculating optimum capacity for central heating systems was part of a Dutch heating industry course: Stichting Vakcursus Verwarmingsartikelen En Kookapparatenhandel


57/74 (ver. 1)Textile System Schirdewan - metric

Original metric version with unique A’ scale - read more ...


57/74 (ver. 2)Textile System Schirdewan imperial

A’ scale from version 1 replaced by LL + wider Imperial version cursor + cm scale on back - read more …


57/74 (ver. 2)Textile System Schirdewan metric

A’ scale from version 1 replaced by LL + inch scale on back - read more …


57/86Columbus Mannheim

narrow


57/87School Rietz
57/88School Rietz-N
57/88 (ver. CH)School Rietz-N

MADE IN SWITZERLAND version


57/89School Log-Log
57/92School Log-Log
61/60Pocket Enhanced Mannheim
61/60/369Pocket Enhanced Mannheim
62/82 (ver. 1)Pocket Technical/Log-Log
62/82 (ver. 2)Pocket Technical/Log-Log
62/83Pocket Technical/Log-Log long-scale

See later 62/83N sibling


62/83NPocket Technical/Log-Log long-scale

See earlier 62/83 sibling - model suffix N denotes new/advanced variant


63/22Pocket Business
63/22RPocket Business Addiator

British pre-decimal £sd bottom bevelled edge scales + addiator pen clip part of stock - AddiatoR on back


63/39Pocket Mannheim
63/54Pocket Darmstadt
63/87Pocket Rietz

1 cursor window in back


63/87RPocket Rietz Addiator

addiator pen clip part of stock - AddiatoR on back


63/91Pocket Enhanced Mannheimpromotional rule for: Atlas Diesel
63/98Pocket Electro
66/92Pocket Log-Log

 inexplicably rare model + Inch scale on back


67/22Pocket Business

for pre-decimal British £sd


67/22RbPocket Business Addiator

for pre-decimal British £sd - AddiatoR on back - model suffix b denotes broader/wider stock


67/34 (ver. 2)Pocket Hermatology - System Dr. Vogel

Specially for haemoglobin/blood analysis


67/39Pocket Mannheim
67/54Pocket Darmstadt

Bayer branding on back 


67/54bPocket Darmstadt

model suffix b denotes broader/wider stock


67/54RPocket Darmstadt Addiator

AddiatoR on back


67/54RbPocket Darmstadt Addiator

Special IM1997 version - AddiatoR on back + model suffix b denotes broader/wider stock


67/54RbPocket Darmstadt Addiator - Export

Henderson, Lindsay& Michaels Inc. (Greenville B.C.) stamped on back of pouch - AddiatoR on back + model suffix b denotes broader/wider stock


67/56bPocket Welding - Schweisstechnik, System Titscher

Specially developed for welders + related formulas the back


67/74 BASFPocket Pigment-Volume-Concentration

Special commission for German chemical company BASF but unusually has a standard F-C model number in the 6x/xx series + table of pigment thicknesses on back


67/87 ArtosPocket Rietz
67/87 SKFPocket Rietz
67/87RPocket Rietz Addiator

AddiatoR on back


67/91Pocket Enhanced Mannheim

model no., etc printed on back because of advert in well of stock


67/98 (ver. 1)Pocket Electro

V and W scales in the well of the stock + “import” stamped in back


67/98 (ver. 1)Pocket Electro - imperial

V and W scales in the well of the stock


67/98bPocket Electro

model suffix b denotes broader/wider stock


67/98RbPocket Electro Addiator

AddiatoR on back - model suffix b denotes broader/wider stock


74/39Lilliput Enhannced Mannheim

Part of strange Lilliput-only series


77/91Lilliput Enhanced Mannheim

42nd Wedding Anniversary present from Ros - part of strange Lilliput-only series​


8/10Rietz

1 of only 8 circular production models F-C made


8/12 DELBAGPipe Flow

For calculating resistance in metal pipes - 1 of only 8 circular production models F-C made


8/168Petroleum

Advertising model Mobil Oil Co. & for showing relationship between different viscosity measuring systems at given temperatures + weight to volumes conversion table on back - 1 of only 8 circular production models F-C made


8/20Pocket Basic

42nd Wedding Anniversary present from Ros - 1 of only 8 circular production models F-C made


8/30Pocket Retail

Outer scale is for calculating a % discount or % surcharge - 1 of only 8 circular production models F-C made


BASF Tonband-Schmalfilm-RechnerPocket Home Audio & Cine Film - System Schirmer

Specially commissioned reused 67/22b body for German chemical company BASF - 8mm & 16mm frames/minute nomogram on back - is this Schirmer same as Demegraph Max Schirmer? ​


ESSO Viskositat V.I. 70-80Petroleum

Specially commissioned by US global oil major ESSO for viscosity related calculations + Conversion tables on back


Heine RealzeitscheibeDesktop Network Planning

Specially commissioned by Georg Heine, Stuttgart + front disc doubles as erasable notepad


Hel (ver. cme) Richtschieber AMilitary Artillery Range Finder

cme = F-C secret WWII code for being made by Wichmann in Berlin - Eagle stamped in well signifying German military authorities - notches top & bottom either end of slide & 4 ball bearings in well stop slide accidentally falling out + plastic stops either end of bottom edge to stop cursor sliding off


Laukhuff OrgelpfeifenDesktop Music Organ Pipes - System Rensch

Specially commissioned by German organ builder Laukhuff (still operating) for scaling organ pipes (wood/metal flues & reeds) based on copyrighted design by German Richard Rensch (1923-1997) but preceded by German Wolfgang Adelung’s earlier (simpler) version - extremely complicated to use (cursor extension + graph paper needed for interim calculations) - superb quality but only 500 ever made - Orgelbau-Verlag started selling their own (inferior) version in 1986


Nijgh & Van DitmarTechnical

Unbranded special commission for Dutch publisher Nijgh & Van Ditmar (founded in 1843 & still operating) - standard scale layout but for folded scales - reputedly complemented a book on calculating tips & tricks (incl. folded scales speeding up certain calculations) - pictograms on back same as model 57/86


Peddinghaus Stanz- und SchnittkraftPocket Steel punching & cutting forces

Specially commissioned by German specialist steel plate supplier Peddighaus (still operating) - table of Maximal Punching Forces on back + sibling for punching & cutting performance


Peddinghaus Stanz- und SchnittleistungenPocket Steel punching & cutting performance

Specially commissioned by German specialist steel plate supplier Peddighaus (still operating) - table of Maximal Punching Forces on back + sibling for punching & cutting forces


SKF F&SBall Bearings

Specially commissioned by Swedish ball-bearing maker SKF & German shock absorber maker F&S (Fichtel & Sachs) with cm scale in well of stock & 2 cursor windows in back + see also 12½ cm SKF F&S pocket Enhanced Mannheim sibling


SKF F&SPocket Mannheim

Specially commissioned version of 63/39 for Swedish ball-bearing maker SKF & German shock absorber maker F&S (Fichtel & Sachs) + see also 25cm SKF F&S sibling with unique scales ​for ball bearings


SPEED Pocket Mannheim

Unusually for F-C an unbranded version of 63/39 specially commissioned for the unknown company “SPEED” (stylised logo in well of stock) & “Import” stamped in back


TR1 (ver. 2)Hybrid electronic calculator

Serial No. 015050144 - red LED display - scale layout chosen to complement basic calculator functions (X2 & 1/X)


TR2Hybrid electronic calculator

Serial No. 027090384 - green LED display - scale layout chosen to complement extended calculator functions (X2, √X, % & 1/X)


TR3Hybrid electronic calculator

Serial No. 034110034 - red LED display - scale layout chosen to complement scientific calculator functions (incl. including log & trig functions)


TR4Electronic calculator

Serial No. 046110135 - green LED display with extended calculator functions but no slide rule


Verlag ChemieChemical

Specially commissioned by German specialist publisher Verlag Chemie - unconventional layout of scales on front with specialist scales + gauge marks for many elements & compounds on back. ​


Versuchs- und Lehranstalt für BrauereiBeer Brewing - System Windisch

Specially commissioned by German institute supporting the beer brewing industry Glasbläserei der Versuchs- und Lehran-stalt für Brauerei - also issued as model 51/80


Abbot Brown & Sons / Smiths (Calculators)
ModelTypeCommentsThumbnail
Blackwell Average Speed Calculator Mk ITime-Speed-Distance rallying calculator Design patented (GB707740) by Harold Blackwell - surprisingly stamped on back “obtainable from Blackwell’s Metallurgical Works Ltd” (was Harold part of a family business?) - later larger duplex Mk II version made
LeeSheet Steel Weight Calculator

For calculating the weight of one or more sheets of steel according to size/thickness of the sheets - made for H.F. Spencer Ltd. - carries the later name of “Smiths (Calculators) Ltd” after Bill Smith sold out to John James


Resistance Chart for Viscous Flow OnlyPipe flowUnmarked/unbranded but style & finish very Abbot Brown like - probably a Stohert & Pitt Ltd advertising giveaway - company folded in 1989 & name sold to Langley Holdings  
Thermocontrol Heat Transmission CalculatorUnmarked/unbranded but style & finish very Abbot Brown like - specially commissioned by Thermocontrol Inst. Co. Ltd
Addiator GmbH
ModelTypeCommentsThumbnail

ADDFEET JuniorPocket Imperial Slide Adder - gold/green

For non-decimal adding/subtracting in feet, inches & 8ths of inch - baby brother version of larger SIZEMATIC model


ARITHMAPocket Slide Adder - silver

For adding/subtracting but cheaper/simpler version of UNIVERSAL model


CALCULEXMultiplication Table

Simple but patented (DE1839275) device mainly for obtaining percentages of values - not to be confused with earlier 1923 slide adder or pocket-watch slide rule types of the same name ​


CREDIT-DEBETSlide Adder (saldo neg.)

Serial no. M 922692 for book-keeping adding/subtracting but with additional display line for negative balances (saldo neg.) on DEBET side


DUPLEXSlide Adder - silver

Extended/bigger version of the ARITHMA model​ - many DUPLEX versions sold


HEXADATHexadecimal Slide Adder for Computer Programmers

Serial no. 670306 patented (DE1963993) design for adding/subtracting in base 16 - table of hex/dec equivalents on back - possibly most impressive & complex slide adder ever made - read more ...​


MAXIMATOR/STORAGESlide Adder (saldo neg.) set (2) - gold/green

Serial no. 214840 front hinged adder for adding/subtracting but with additional display line for negative balances (saldo neg.) on subtraction side - smaller adder underneath for storing interim or working results (modern memory function) ​


PRO CALCULO!Slide Adder

Primarily a basic adder just for addition but as shown in the instructions via a workaround subtraction is possible 


SIZEMATICImperial Slide Adder - gold/brown

Serial no. 695205 - for non-decimal adding/subtracting in feet, inches & 16ths of inch - big brother version of ADDFEET Junior model


UNIVERSALPocket Slide Adder (saldo neg.) - gold

For adding/subtracting but with additional display line for negative balances (saldo neg.)


Addimult Rechenmaschinenfabrik
ModelTypeCommentsThumbnail
PROCENTORPocket Basic Retail

Also sold as notepad wallet set with a SUMAT 6 slide adder​


SUPRASlide Adder

Made in Sweden for adding/subtracting but because of Addiator metal sheath/case possibly a transition model as son Hans-Wolfgang Kübler set up his own business after working for his father Carl at Addiator


Adix Company
ModelTypeCommentsThumbnail
Adix 1Column Adder

First generation model (later models had a zero reset lever & brass components) designed by German clockmakers Pallweber & Bordt for for simple addition.


Aero Products Research Inc.
ModelTypeCommentsThumbnail
ERJAVECMusic Composition

Slide chart copyrighted Music Theory Wheel design by Donald L. Erjavec


AHREND (Wed. J. Ahrend & Zoon)
ModelTypeCommentsThumbnail

(P281)Demonstration Rietz

made by unknown 3rd party for Hemmi models P280/P281 - Rietz layout but all scales on front face


435064 (89)Pocket Rietz

OEM by ARISTO + reversed inch scale, cursor window with 1 hairline, Ahrend branding & closed Dutch industrial motor manufacturer De Industrie in back


435660 (P280)Darmstadt-like two-tone

OEM by HEMMI


435661 (P281)Rietz-like two-tone

OEM by HEMMI


435662 (P283)Technical two-tone

OEM by HEMMI


642TRietz

OEM by HEMMI as wider version of 64T Extended Rietz + T model no. suffix possibly = basic 64 with extra Trig scales + table of constants & green pads on back + earlier thinner 64T sibling - also sold as Ahrend 643T


74Pocket Rietz - late

OEM by HEMMI with improved layout because of extra peripheral hairlines on cursor + metal backing plate + Dutch retailer Ahrend printed on back


791/7Diagonal Scale

Used with a set of dividers for scale ratios 1:1000, 1:5000,1:1250 & 1:2500​


810Diagonal Scale

Used with a set of dividers for scale ratios 1:1000, 1:5000,1:1250 & 1:2500​


ELECTRO 15Electro

OEM version made by KHH (5 slits in well + 5 adjustment screws on bottom side edge) but often mistaken as D&P because of model no. - V & W scales in well of stock + conversion tables (in NL) & 2 cursor windows in back - see also identical model sold by, Johann Faber, OHICO & Kahn Frères


ELECTRO 654Electro

OEM by KHH (5 slits in well + 5 adjustment screws on bottom side edge) & identical to Electro 15 model but possibly renumbered to avoid confusion with D&P model no. - V & W scales in well of stock + conversion tables (in NL) & 2 cursor windows in back


HOLLANDIA-REKENSTOKEnhanced Mannheim

Hollandia-Rekenstok = Dutch calculating stick - OEM version by Dennert & Pape & 1st slide rule in Ahrend catalogue - cm scale in well of stock + conversion tables (in NL) on back


NORMAL 650 (Ver. 1)Enhanced Mannheim

OEM by KHH (5 slits in well + 5 adjustment screws on bottom side edge) + conversion tables (in NL) & 2 cursor windows in back


NORMAL 650 (Ver. 2)Enhanced Mannheim

OEM by KHH (1 slit in well + 5 adjustment screws on bottom side edge) + conversion tables (in NL) & 2 cursor windows in back


RIETZ 652Rietz

OEM by KHH (1 slit in well + 5 adjustment screws on bottom side edge) + conversion tables (in NL) & 2 cursor windows in back


RIETZ 690 (89)Pocket Rietz

OEM by ARISTO + reversed inch scale, cursor window with 1 hairline & Ahrend branding in back


Albert Martz
ModelTypeCommentsThumbnail
System FrankPocket long-scale - model 2

​Is wide-bodied & based on original Swiss patent (CH26145) by Wilhelm Frank - table of constants on back


ALKU (Alfred Kuhmann)
ModelTypeCommentsThumbnail
(NoName)Chemical/Concrete poly-slide (3)

Extra wide body + 3 pairs of non-standard scales (MN, FE, P) are for chemical elements & other 3 pairs are for oxides (CAO, Al2O3, SIO2) - read more ... or try out here the online simulation created by Andries de Man


ALRO (All-Round)
ModelTypeCommentsThumbnail

KWARTETSCHUIF (AC-5.04)Printing - yellow

Slide chart with © design made for a consortium of 4 Dutch regional newspapers so customers for calculating advertising costs of chosen layout & size (once-off or repeated) in Dutch Gulden - cm & Cicero scales on back + maybe prototype for white version as without cut-outs for easy movement of slide


VICON 17880570 (AC-2.05b)Agriculture

Slide chart/slide rule by Dutch supplier of farming machinery VICON (VIssers Construction Nieuw-Vennep) for calculating fertilizer distribution + see also sibling version


10 R (AC-1.45a)Waistcoat Rietz

Listed 1st in catalogue from 1950 


100 R (AC-1.04a)Rietz - H

With the primary scales nearest to the rim this layout offered great precision (scale length 28cm) over the more popular 200 R that had the Trig scales nearest to the rim + codes H alongside central nameplate probably = country code for Holland


100 R (AC-1.04b)Rietz - early

With the primary scales nearest to the rim this scale layout offered great precision (scale length 28cm) over the more popular 200 R that had the Trig scales nearest to the rim 


1010 Commercial (AC-1.17)Business long-scale

Double cursor version of innovative but impractical single long-scale 6-spiral patented (CH265561) design + tables of conversion factors in lid - try out an online simulation created by Andries de Man


1010 Commercial (AC-1.18)Business long-scale

Single cursor version of Innovative but impractical single long-scale 6-spiral patented (CH265561) design  + tables of conversion factors in lid - try out an online simulation created by Andries de Man


200 R (AC-1.05a)Rietz

​Table of conversion factors in lid  + Dutch retailer Bladergroen was an stationer from 1903 to 1980 when it was bought out & name changed to Berlage  - try out an online simulation created by Andries de Man


200 R (AC-1.05a)Rietz - green finish

One of four metal box finishes (2 x metal & 2 painted) occasionally used


200 R (AC-1.05a)Rietz - H early

Code H alongside central nameplate probably = country code for Holland + table of conversion factors in lid


200 R (AC-1.05a)Rietz - two-tone paper discs

The use of two-tone paper discs is probably for better contrast/legibility - table of conversion factors in lid


200 R (AC-1.05b)Rietz - chrome finish

One of four metal box finishes (2 x metal & 2 painted) occasionally used


200 R (AC-1.05b)Rietz - copper finish

One of four metal box finishes (2 x metal & 2 painted) occasionally used


200 R (AC-1.05b)Rietz - early

Conversion chart (fractions/decimals) in lid


200 R (AC-1.05b)Rietz - green paper discs

Reason for non-standard green/turquoise paper discs & for polished inside box is unknown


200 R (AC-1.05b)Rietz - H

​Code H alongside central nameplate probably = country code for Holland + ​conversion chart (fractions/decimals) in lid


200 R (AC-1.05b)Rietz - H zinc

Because of a shortage of aluminium during WWII the metal boxes looked identical but for a short time were made of much heavier zinc + code H alongside central nameplate probably = country code for Holland + ​conversion chart (fractions/decimals) in lid


200 R (AC-1.05c)Rietz - no stand

Unconventional 200 R with black heavy-duty metal back plate instead of desk stand - reminiscence of military model with just a back plate  


200 RL (AC-1.49a)Rietz

RL = Rietz Liniaal (ruler) + failed project to make white plastic linear model + 2 windows with hairline, two expansion slots & table of constants for metals on back - part of prototype batch of +/- 50  


200 RL (AC-1.49b)Rietz - monochrome

RL = Rietz Liniaal (ruler) + later (CI scale no longer red) improved version with self-lubricating bearings + 2 windows with hairline, two expansion slots & table of constants for metals on back


300 D (AC-1.08a)Darmstadt

Version without a P scale + table of conversion factors in lid - subsequently succeeded by 400 D


300 D (AC-1.08b)Darmstadt - early

Version with added P scale + table of conversion factors in lid - subsequently succeeded by 400 D 


400 D (AC-1.09)Darmstadt

Successor to 300 D with many more gauge marks & CI replacing S&T & P in lid + table of conversion factors in lid ​- see also larger sibling


400 D (AC-1.nn)Desktop Darmstadt

See also smaller sibling - conversion table of fractions also on back 


50 Ng (AC-1.47)Waistcoat Basic Printing/Conversion

Ng = Normaal (normal) grafici (printers) ​+ scales on back convert mm into cicero’s/didot points


50 Nmmi (AC-1.46a)Waistcoat Basic/Conversion

Nmmi = Normaal (normal) mm to inches + scales on back convert metric mm into imperial inches  


500 N (AC-1.11)Basic

N = Normaal (normal) & is possibly successor to Ha.A2 but with smaller font to make more room for advertising + see also larger sibling 


500 N (AC-1.nn)Desktop Basic

N = Normaal (normal) + personally enhanced (lighter plastic outer baseplate & peripheral cursor hairlines) model of last ALRO Technical Director Han Wanders - see also smaller sibling 


500 N Vergouts (AC-1.11)Basic

N = Normaal (normal) & is possibly successor to Ha.A2 but with smaller font to make more room for advertising such as Belgium photographers Vergouts + tables of conversion factors from 1010 Commercial in lid


600 E (AC-1.19)Electro

Rare example of circular Electro type ​


700 H Philips Emission (AC-1.26)Radio Electronics - early

H model number suffix = High Frequency with special scales for inductance, capacitance & resonance + CJD monogram for company co-founder Dussel indicates an early model + scales in lid provide the dB figure for various power & voltage ratios - probably inspiration for the much later modern plastic Decibel PTT models  


746 De Muiderkring (AC-1.27) Radio Electronics

De Muiderkring = the Dutch publishing arm of Amroh (American Radio House) specialising in radio technology + pictogram colour coding & table of resistances for condensers in lid - see also waistcoat sibling


746 De Muiderkring (AC-1.nn)Waistcoat Radio Electronics

De Muiderkring = the Dutch publishing arm of Amroh (American Radio House) - see also larger sibling 


ABN SZ 14501(AC-5.02)Finance

Slide chart made for Dutch high street bank ABN (later merged with another bank to become ABN-AMRO) for calculating compound interest monthly payback on a 100 Dutch Gulden loan for rate of 11 to 15.5% (front) & 15.75 to 20% (back) for durations of 12 to 60 months  


AL-RO (AC-1.01)Basic Retail- prototype

 AL-RO model designation (never repeated) is a reference to the full company name + CJD monogram for company co-founder Dussel & earliest pre-production model from original Wildhoeflaan 21 address in The Hague + imperial conversion factors in lid - metal box maybe a replacement   


ALRO (AC-6.04a)Time/Conversion

Slide Chart version 04a to promote ALRO's trade-marked process ALRODEREN or laminating paper in thin plastic & converting time across 7 times zones for 28 cities around the world


ALRO (AC-8.09)Pocket Measuring - transparent

Ruler/protractor to promote/advertise ALRO company  


ALRO (AC-8.nn)Measuring

Ruler to promote/advertise ALRO company & their PVC products + special version for Amsterdam Efficiency Fair of 1986


ALRO (AC-8.nn)Measuring - German

Ruler to promote/advertise ALRO company & durability of their ALRODEREN process for German market


ALRO BOVI (AC-6.04a)Time/Conversion

Slide Chart version 04a made for Dutch sales promotion company BOVI for converting time across 7 times zones for 28 cities around the world


ALRO-PATENT (AC-1.02)Basic Retail - prototype

Model designation clearly pre-empting soon to be granted international patents + early pre-production & synonymous with Ha (= Handel -= Retail) + imperial conversion factors - try out an online simulation created by Andries de Man in lid 


ALRODEREN (AC-8.01)Measuring - transparent

Ruler made to promote ALRO's trade-marked process ALRODEREN or laminating paper in thin plastic + image of office facade in The Hague + horse-head company logo 


ALRODEREN (AC-8.01)Measuring - white

Ruler made to promote ALRO's trade-marked process ALRODEREN or laminating paper in thin plastic + coloured image of office facade in The Hague + horse-head company logo 


ALRODEREN (AC-8.08)Colour Sampler

Ruler come sampler for to promote ALRO's trade-marked process ALRODEREN or laminating paper in thin plastic for their head office and only German subsidiary


ALROPRINT (AC-8.nn)Colour Sampler

Sampler to promote/advertise ALRO company & quality of their ALROPRINT (synonymous TM with ALROCARD) finish 


AMI-RO-METER (AC-4.01)Cardiology

Slide chart made for Dutch research-driven global pharmaceutical company Boehringer Ingelheim for calculating  probability of myocardial infarction (heart attack) in patients with history of heart problems + AMI-RO = Acute Myocardial Infarction Rotterdam ​


ASTRA (AC-4.14)Medical

Slide chart made for Swedish pharmaceutical company Astra that merged with British Zeneca Group in 1999 to form AstraZeneca for finding the anaesthetic pain control dosage for 31 different types of surgical operation  


Azimuth (AC-1.31)Astro Navigation - System van der Zalm

Calculates the angular measurement in a spherical coordinate system or more the horizontal angle from a cardinal direction


B.I.P.M. DRILLING (AC-2.01)Petroleum

​Slide chart for calculating optimum drilling of wells according to factors such as penetration rate, drill speed, hydraulic pressure drop, etc + B.I.P.M. = Bataafse Internationale Petroleum Maatschappij or forerunner of company now known as Shell


B.I.P.M. MUD WEIGHT (AC-2.02)Petroleum

Slide chart for calculating needed & allowable maximum mud weight for a drilled & flowing well according to factors such as depth, pressure within drill pipe, annular surface pressure, etc + B.I.P.M. = Bataafse Internationale Petroleum Maatschappij or forerunner of company now known as Shell


BBL TRADELINK (AC-6.04e)Pocket Time/Conversion

Slide chart version 04e made for Belgium Bank Brussel Lambert (BBL) (Tradelink was the name of their network but bank later acquired by Dutch ING bank) for converting time across 7 times zones for 28 cities around the world


BIONORM (AC-4.13)Dietary/Conversion

Slide chart made for 100% plant-based organic branded bioNorm proteins to convert Joules to Calories 


BoB3 (AC-1.nn)Reinforced Concrete - System Dussel

Personally designed by company co-founder C.J. Dussel + BoB3 = possibly Beton (concrete) & part of alternative model numbering system + possible forerunner to later (?) Beton version but with additional 70 kg/cm2 scale & extensions for extra strong cement + scales in  lid are for calculating no. & size of reinforcement bars


BOEHRINGER INGELHEIM (AC-4.17a)Pocket Cardiology

Ruler made for German pharmaceutical company Boehringer Ingelheim & designed by F.A.M. Harms for analysing ECG printouts of cardiac Sinus Rhythms - read more ….  


BOLS (AC-4.19)Mixology

Slide chart made for Dutch distillery Lucas Bols for mixing 30 different cocktails + tips for mixing drinks on back of slide


BROEISCHIJF (AC-2.09)Horticulture

Slide chart designed by Dutchman Wim Granneman in 1975 to calculate how to alter/change flowering/harvesting time of tulip bulbs + can also be used for other perennials & other countries with different seasons + issued by Dutch International Flower Bulb Centre


CARBORUNDUM (AC-2.11)Wallet Machining

Slide chart for defunct Dutch subsidiary tool merchant of The Carborundum Company in the form of a wallet for determining machine settings - i.e. speed (rpm) for given diameters of types & coatings of grinding discs + speed table    


CFM (AC-8.11)Printing

Slide chart made for defunct Dutch factory making printing forms of illustrations Clichéfabriek Maastricht for calculating % reduction/increase when for typesetting/engraving 


Chem (AC-1.23)Chemical

Chemical credence comes from over 140 chemical-related gauge marks + table of all atomic weights from 1948 in lid - see also online simulation by Andries de Man 


CINCINNATI MILACRON (AC-2.17a)Machining - ver. 1

Slide chart for defunct Dutch subsidiary of USA machine tool builder Cincinnati Milacron with copyrighted design (1 moving ring) for calculating grinding parameters  + see also advanced sibling


CINCINNATI MILACRON (AC-2.17b)Machining - ver. 2

Slide chart for defunct Dutch subsidiary of USA  machine tool builder Cincinnati Milacron with copyrighted design (2 independently moving rings) for calculating grinding parameters  + see also basic sibling


COLORSTAR (AC-8.03)Photographic

Slide chart/nomogram (n.b. not a slide rule) made for Dutch supplier of photographic darkroom products LiCi Colorstar for calibrating their early range of colour analysers in combination with a test print


CORDARONE (AC-4.06)Pocket Cardiology

Ruler (unusually fitted with a cursor) made for American pharmaceutical company Wyeth-Ayerst Laboratories (acquired by Pfzier in 2009) & registered brand name owner of Cordarone (drug for irregular heart beats) for analysing ECG printouts of cardiac Sinus Rhythms - read more ….  


CORDARONE (AC-4.06)Pocket Cardiology - prototype

Ruler (unusually with a cursor) probably prototype for American pharmaceutical company Wyeth-Ayerst Laboratories (acquired by Pfzier in 2009) & brand name owner of Cordarone (drug for irregular heart beats) for analysing ECG printouts of cardiac Sinus Rhythms + unlike sibling has plain back 


DAST (AC-6.01)Lilliput Calendar

Slide chart DAST = DAtum (date) STandaard (standard) is a perpetual calendar for the years 1300 to 2499


DATA CARD (AC-6.04c)Time/Conversion

Slide Chart version 04c made for defunct Euro-American card manufacturer Data Card (they later bought ALRO & in turn was acquired by conglomerate Entrust) for converting time across 7 times zones for 28 cities around the world


DATA CARD (AC-6.04d)Time/Conversion

Slide Chart version 04d made for defunct Euro-American card manufacturer Data Card (they later bought ALRO & in turn was acquired by conglomerate Entrust) for converting time across 7 times zones for 28 cities around the world


DE BUCK & PAULICH (AC-8.10) Printing

Slide chart made for defunct Belgium photo engravers De Buck & Paulich for calculating % reduction/increase when for typesetting/engraving 


DE ECHTE BAKKER (AC-6.04a)Time/Conversion

Slide Chart version 04a made for Dutch guild of artisan bakers De Echte Bakker for converting time across 7 times zones for 28 cities around the world


DE KINKELDER (AC-6.03)Pocket Building

Slide chart made for Dutch construction company Gebr. de Kinkelder B.V. for calculating spread of workable days/month throughout the year - front for maximum of 200 working days/year & back for maximum of 191 (allowing for lost days due to high winds) working days/year  


DELTA LLOYD (AC-2.25)Pocket Building Measuring

Slide chart/ruler made for Dutch insurance company Delta Lloyd with unusual mirrored (anamorphosis) scale to measure thickness of framed glass by placing the bevelled top edge against the glass surface & reading off the thickness from the reflection


DEMABO (AC-8.nn)Pocket Measuring

An architects ruler made for defunct Dutch construction company Demabao Systeembouw  


DIKEMA EN CHABOT (AC-2.14)Steel Bars

Slide chart made for defunct Dutch steel wholesaler Dikema en Chabot for calculating size & weight for a given length of steel bar with either a H or U profile 


DISCABOIS (AC-1.24)Forestry - System Brouhon

Patented design (BE492292) by J.L. Brouhon from 1949 for wood merchants, wood sawmills, etc + tables of conversion factors from 1010 Commercial in lid + price included surcharge over other Ø 13cm models - see also online simulation by Andries de Man 


DOSSCHE (AC-2.08)Pocket Agriculture

Slide chart for defunct Belgium cattle-feed supplier (factories in Deinze & Zolder) Dossche for calculating the estimated respective gestation time for pigs, sheep, cattle & horses


ELASCON (AC-8.02)Building

Template made for defunct Dutch construction company Electra LAS COmbinatie Nederland (Elascon) for drawing profiles of metal roofing or cladding panels   


EMF DORDT (AC-3.10)Electro

Slide chart for calculating power, efficiency & wiring of electric motors + EMF DORDT = nickname of defunct Dutch company Willem Smit & Co.‘s Electromotorenfabriek that produced large commercial electrical motors


ETBI (AC-5.03)Paper

Slide chart made for defunct Dutch wallpaper company Eerste Twentse Behang Industrie (ETBI) for calculating total price in Dutch Gulden for buying 7 to 12 rolls of wallpaper in price range of fl 1.20 to 5.85/roll  


FINNCELL (AC-2.12)Tiber

Slide chart for defunct Finish company Finncell showing location, capacity & types of product produced at each of their 29 wood pulp/cellulose mills in Finland    


Geluidsniveauverschil van gevels (AC-7.03)Building Facades

Slide rule/slide chart for calculating sound levels in dB for building facades - © 1983 design by ministerie  V en M = now defunct Dutch Ministerie van Volksgezondheid en Milieuhygiëne (Ministry of Health and Environmental Hygiene)


GEVAERT (AC-8.07)Photographic

Slide chart made for Belgium manufacturer of photographic paper L. Gevaert & Cie (later became Belgium-German multinational company Agfa-Gevaert) for calculating how to optimally reproduce photographic images mechanically using an inked plate created from a photographic negative  


GIST-BROCADES HWV (AC-2.18)Cooking

Slide chart made for defunct Dutch chemical & pharmaceutical company Gist-Brocades N.V. for calculating % of water to flour needed for 30 small or large pieces of dough for 13 different types of bread  


GRASSO-PERSLUCHT (AC-2.22)Refrigerant/Conversion

For air pressure & flow calculations + GRASSO-PERSLUCHT = Dutch company for industrial refrigeration equipment + table of constants/conversion factors & ALROPRINT on back 


GRAVURA (AC-1.47) Waistcoat Basic Printing/Conversion

Specially commissioned 50 Ng for Gravura N.V.  a printer & illustrator based in Dutch town of The Hague


GTI INSTALLATIETECHNIEK (AC-2.10)Central Heating

Slide chart for converting heat transfer values in central heating systems + gti installatietechniek = Dutch plumbing company + ALROPRINT & © TRD/1977/10


Ha Tex (AC-1.15) Business/Textile - early

Ha Tex = Handel (business) Textiel (textiles) for textile-based calculations with UK pre-decimal £sd currency & yards


Ha Tex (AC-1.16b) Business/Textile

Ha Tex = Handel (business) Textiel (textiles) for textile based calculations with UK pre-decimal £sd currency & yards + tables of conversion factors from 1010 Commercial in lid - see also online simulation by Andries de Man


HA-ES Perfecta-Kiezer (AC-2.26)Heating Pumps

Slide chart look-up table on back to help select most suitable heating pump for commercial use (e.g. greenhouses) from HA-ES “perfecta” range made by defunct Dutch company Meppeler Machinefabriek


Ha.A2 (AC-1.12)Basic Retail

Ha.A2 possibly part of alternative model numbering system & predecessor to 500 N AC-1.11 but with larger font & 4 pre-decimal & imperial conversion scales in lid + prefix Ha = possibly Handel (retail)


HAVAM (AC-2.20)Motoring/Conversion

Slide chart for defunct Dutch car parts retailer HAVAM for torque settings + pressure & usage conversion tables  


HAVAM (AC-2.21)Conversion

Slide chart for defunct Dutch car parts retailer HAVAM for converting UK/USA imperial values to metric  


HEWLETT PACKARD (AC-4.17b)Pocket Cardiology

Ruler made for American multinational IT company Hewlett Packard (HP) & designed by F.A.M. Harms for analysing ECG printouts of cardiac Sinus Rhythms - read more ….  


HOECHST (AC-4.08)Dermatology

Slide chart made for German chemicals/life-sciences company Hoechst AG (later became Sanofi Aventis) using a pair of dividers to measure size of elliptic skin sores (Laesiomat is Latin for hurting) & calculate area in mm2 + adverts for branded skin salves on back 


HOECHST (AC-4.10)Cardiology - transparent

Ruler Cor-V-Mat® incorporating nomograms made for German chemicals/life-sciences company Hoechst AG (later became Sanofi Aventis) & designed by Prof. Keuskamp for analysing ECG printouts of cardiac Sinus Rhythms - read more ….  


HOEK LOOS (AC-4.07)Paediatrics

Slide chart made for defunct Dutch producer of oxygen & other gases Hoek Look for Amsterdam Infant Ventilator Machine designed by Prof. Keuskamp for calculating respiration flow rates & air/oxygen flow rates 


IBM 00685 (AC-8.06a)Typometer Composer

Ruler made for American International Business Machines (IBM) for working in Cicero, Pica & IBM typographic units with typewriters


IBM 00687 (AC-8.06b) Typometer Composer

Ruler made for American International Business Machines (IBM) for working in Points, Cicero, Pica & IBM typographic units in desk-top publishing 


KLIMAATKONTRAKT (AC-2.19)Desktop Energy Saving

Slide chart made for & © designed by KK/TRD consisting of consisting of 4 rings of energy saving tips ranked by low/medium/high investment levels for: (i)  heating systems (front) or (ii) lighting, energy & sanitation (back) 


Klinische Rekencirkel (AC-1.39)Desktop Medical - System Lips

Highly complex specialised layout of scales designed by Dr. A. Lips + facilitates 26 medical based calculations (metabolic-related on front & blood ph/gasses on  back) - read more … or try out  Andries de Man's two online simulations: (i) front & (ii) back 


KLM (AC-6.04c)Time/Conversion

Slide Chart version 04c made for Dutch airline KLM for converting time across 7 times zones for 28 cities around the world


KLM AIR FREIGHT (AC-2.16)Aviation

Slide Chart made for Dutch airline KLM for calculating dimensional or volumetric weight (imperial or metric) based on a package's length, width & height using benchmark of either 7 cubic decimetres = 1 kg or 194 cubic inches = 1 Lb 


KLM CONVAIR 240 (AC-1.nn)Aviation

Load adjuster (possibly pre-production) made for Dutch airline KLM who had 1st fleet in Europe of American-made Convair 240 passenger planes - see also earlier prototype sibling  


KLM CONVAIR 240 (AC-1.nn)Aviation - prototype

Load adjuster prototype made for Dutch airline KLM who had 1st fleet in Europe of American-made Convair 240 passenger planes + table of conversion factors in lid - see also later (possibly pre-production) sibling


KLM FLYING DUTCHMAN (AC-6.nn)Time/Conversion

Slide chart made for frequent flyer/loyalty programme of Dutch airline KLM for converting time across 7 times zones for 117 KLM destinations around the world 


KLM Petrol & Oil Tables (AC-1.29)Petroleum/Conversion

Slide chart made for Dutch airline KLM (old style logo) for converting imperial & US gallons to lbs, kg, etc for range & loading calculations - see also all-metal early version & prototype


KLM Petrol & Oil Tables (AC-1.29)Petroleum/Conversion - early

All-metal silver coloured slide chart made for Dutch airline KLM (old style logo) converting imperial & US gallons to lbs, kg, etc for range & loading calculations - see final production model


KLM Petrol & Oil Tables (AC-1.29)Petroleum/Conversion - prototype

Prototype slide chart made for Dutch airline KLM (old style logo) converting imperial & US gallons to lbs, kg, etc for range & loading calculations + strange reference to Portugal's Lisbon Portela airport- see final production model


KLM SYST ALRO - System van Roon (AC-1.35)Desktop Aviation

Desktop version of smaller GoA with high-precision goniometric layout (double length Trig scales) by van Roon + specially commissioned flight computer for Dutch airline KLM for calculating course & wind correction 


KLM Take-off & Cruise Power (AC-2.15)Aviation

Slide Chart for Dutch airline KLM for calculating the BMEP (Brake Mean Effective Pressure) for 3 series' of engine   


KLOOS (AC-1.30)Steel Constructions

Slide chart for calculating steel forms needed to construct: (i) fixed & opening bridges & (ii) points & crossing for railways & tramways + KLOOS = F. Kloos en Zonen’s originally a Dutch ship builder that evolved into making all manner of heavy-duty steel constructions


KNM BEGEMANN (AC-2.27)Pipe Flow

Slide chart for calculating resistance in pipes (front) & pump capacity needed (back) + KNM Begemann = defunct Dutch company Koninklijke Nederlandsche Machinefabriek v/h E.H. Begemann manufacturing pumps & steel constructions + table of resistance values on back ​


KWARTETSCHUIF (AC-5.04)Printing - white

Slide chart with © design made for a consortium of 4 Dutch regional newspapers so customers for calculating advertising costs of a chosen layout & size (once-off or repeated) in Dutch Gulden + cm & Cicero scales on back    


LiCi Transistor CdS (AC-1.41)Pocket Photographic

Unusual battery-driven light exposure meter (with built-in micro measuring cell) made for for Dutch supplier of photographic darkroom products LiCi Colorstar according to a copyrighted design by Phlip van Meeuwen (GFK) 


LILLY (AC-4.18)Dietary

Slide chart eating guide made for Dutch subsidiary of American pharmaceutical company Eli Lilly & jointly issued with the Dutch Diabetes Society for finding kcal, Kh(g) & MK (= meal code) values for many types of food & drink 


MILITAIRE REKENSCHIJF (AC-1.32)Military Terrain Analysis

Made for Dutch Army with scales calibrated in NATO Milliradian (Mils) ​for angular measurement + pouch with belt clip shows it was intended for use in field of action 


MILITAIRE REKENSCHIJF (AC-1.33)Military Terrain Analysis - monochrome

Made for Dutch Army with scales calibrated in NATO Milliradian (Mils) ​for angular measurement but being metal cased version was for army barracks or classroom/study 


MILITARY CALCULATOR (AC-1.nn)Military Terrain Analysis

Made foreign armies with scales calibrated in NATO Milliradian (Mils) ​for angular measurement but being metal cased version was for army barracks or classroom/study 


MOEDERS VOOR MOEDERS (AC-4.11a)Pocket Obstetrics - lime green

Slide chart made for founding company Organaon for pregnant mother’s in early stages of pregnancy for planning when to donate urine to help other couples with fertility problems + Moeders voor Moeders = Dutch pharmaceutical organisation that extracts hCG hormone from the urine to create fertility medicines + see also larger version


MOEDERS VOOR MOEDERS 01/10/038 (AC-4.11b)Obstetrics

Slide chart for pregnant mother’s in early stages of pregnancy for planning when to donate urine to help other couples with fertility problems + Moeders voor Moeders = Dutch pharmaceutical organisation that extracts hCG hormone from the urine to create fertility medicines + see also pocket versions


MOEDERS VOOR MOEDERS 038 (AC-4.11a)Pocket Obstetrics - emerald green

Slide chart for pregnant mother’s in early stages of pregnancy for planning when to donate urine to help other couples with fertility problems + Moeders voor Moeders = Dutch pharmaceutical organiation that extracts hCG hormone from the urine to create fertility medicines + see also larger version 


MOEDERS VOOR MOEDERS 88/05/038 (AC-4.11a)Pocket Obstetrics - blue

Slide chart for pregnant mother’s in early stages of pregnancy for planning when to donate urine to help other couples with fertility problems + Moeders voor Moeders = Dutch pharmaceutical organisation that extracts hCG hormone from the urine to create fertility medicines + see also larger version


MSD CO-RENITEC (AC-6.04d)Time/Conversion

Slide Chart version 04d made for American biopharmaceutical company MSD (Co-Renitec is brand name for a high blood pressure treatment) for converting time across 7 times zones for 28 cities around the world


NATIONALE VERKEERSAKAMEDIE TILBURG (AC-7.05)Transport - black

Slide rule/slide chart for predicting traffic sound levels according to several parameters such as type of road, type of vehicle, etc according to design by H.J. van Zuylen + Nationale Verkersakademie Tilburg = defunct Dutch technical school in Tilburg for educating traffic specialists


NATIONALE VERKEERSAKAMEDIE TILBURG (AC-7.05)Transport - green & black

Slide rule/slide chart for predicting traffic sound levels according to several parameters such as type of road, type of vehicle, etc according to design by H.J. van Zuylen + Nationale Verkersakademie Tilburg = defunct Dutch technical school in Tilburg for educating traffic specialists


NAUTA & HAAGEN (AC-8.12)Printing

Slide chart made for defunct Dutch digital printers Nauta &  Haagen (later Kampert-Nauta) for calculating % reduction/increase when for typesetting/engraving 


NEC (AC-6.04b)Time/Conversion

Slide chart version 04b made for Dutch consultancy consortium Nederlandse Export Combinatie (NEC) for converting time across 7 times zones for 28 cities around the world 


Ned. Octr. Aangevr. (AC-1.03)Rietz

Ned. Octr. Aangevr. = Dutch patent applied for so possibly an early pre-production model with CJD monogram for company co-founder Dussel + imperial conversion factors in lid - sadly metal box & patent nameplate are replacements   


NIPO (AC-7.09)Statistics

​Slide chart for calculating the significance between two independent statistical samples + NIPO = Nederlands Instituut voor Publieke Opinie (Dutch institute for public opinion) + table of conversion factors for reliability on inner slide


NoName (AC-6.02)Time

Slide chart made for unnamed company or organisation (but where form. 5007 03-90 60.06 has some meaning) for calculating duration in hours (maximum two weeks) between two daytime timeslots in a calendar week


NoName (AC-6.06)Aviation/Conversion

Unusual slide rule/slide chart/nomograms (2 x Ø 7½cm discs) made for unnamed company or organisation (but Ka6 is a single-seater glider built by Alexander Schleicher GmbH & Co in Germany) for use as simple flight computer & for wind speed conversion + flying check-lists on back 


NoName (AC-8.04)Military Measuring

Protractor/ruler without any branding but classic 180⁰ scale is paired with NATO military favoured alternative: MILS   


NUTRICIA (AC-4.04)Pocket Paediatrics

Slide chart made for Dutch founded healthcare company Nutricia that later became part of French conglomerate Danone for calculating, according to a baby's weight, number & size daily doses for 6 baby food/nutrition products   


Oil Spill (AC-7.06) Petroleum

​Slide chart with © design Dept. of Transport & Public Works of The Netherlands for predicting the probable outcome of an oil spill based on spread, drift, mass balance, evaporation, dispersion & emulsification


ORGANON (AC-4.15)Obstetrics

Nomogram made for global healthcare company Organon showing contraception efficacy of 2 estragon & 9 other oral contraceptives for differing parts of menstrual cycle  


PHILIPS (AC-7.08)Military Quality Control

Slide chart made for Dutch electronic multinational Philips for determining Acceptable Quality Level % (AQL) according American military defence standard (MIL-STD-105-D) showing maximum acceptable number of defects for a given batch size with either Single or Double samples for: Normal (N), Tightened (T) & Reduced (R)


PHILIPS AUDIO COMMUNICATIIONS (AC-3.02)Electro/Conversion

​Slide chart for Dutch electronic multinational Philips for calculating dB decibel ratios & converting them into various current, voltage & power ratios + 1 of 3 versions


PHILIPS DATA SYSTEMS (AC-3.11)Desktop Electronics for computer programmers

Slide chart made for Dutch electronic multinational Philips with © design for their P300 bookkeeping minicomputer showing available functions according memory sectors A to S


PHILIPS ELA 17 8100 70 316221 (AC-3.03)Electro/Conversion

Slide chart/nomogram for ELA (Electro-Acoustiek) division of Dutch electronic multinational Philips for calculating dB decibel ratios & converting them into various current, voltage & power ratios + 1 of 3 versions


PHILIPS ELA 68/43/4112 (AC-3.01)Electro/Conversion

Slide chart/nomogram for ELA (Electro-Acoustiek) division of Dutch electronic multinational Philips for calculating dB decibel ratios & converting them into various current, voltage & power ratios + earliest of 3 versions  


PHILIPS MEDICAL SYSTEMS (AC-4.12)Pocket Obstetrics

Slide chart made for Dutch electronic multinational Philips for calculating foetal size & age from crow-rump length (CRL) or foetus length from top of head to bottom of torso & biparietal scull diameter (BPD) ultrasound results


PHILIPS MINIWATT Transistors (AC-3.05)Electronics

Slide chart for Dutch electronic multinational Philips to  check specificatiions for OC series of tansistors 


PHILIPS MINIWATT Valve Pins (AC-3.07)Electronics - blue

Slide Chart (later version) made for Dutch electronic multinational Philips for showing 8-pin layout (a=anode, f=filament, g=grid, h= heated, k=cathode & i.c.= internally connected) of Miniwatt range of valves + see earlier sibling  


PHILIPS MINIWATT Valve Pins (AC-3.07)Electronics - green

Slide chart (early version) made for Dutch electronic multinational Philips for showing 8-pin layout (a=anode, f=filament, g=grid, h= heated, k=cathode & i.c.= internally connected) of Miniwatt range of valves + see also later sibling  


PHILIPS Resistors (AC-3.08)Electronics

Nomogram made for Dutch electronic multinational Philips for designing 6 different carbon film resistors with 3 different resistor values 


PHILIPS TELECOMMUNICATION DECIBEL (AC-1.44)Waistcoat Radio Electronics

Larger versions made for PTT 


PHILIPS TV Control Unit (AC-3.13)Electronics

Slide chart made for Dutch electronic multinational Philips for step-by-step set up/troubleshooting schematics & settings of XG 7100/XG 7104 TV control unit


PLANISFEER (AC-6.05)Desktop Astronomy - Northern Hemisphere

Slide chart designed as planisphere by Dutchman R. Walrecht to calculate star positions & star signs at latitude 52º North & longitude 5º East for given date & time + just 1000 made but later versions made by PlantijnCasparie 


PLANOSEC (AC-4.09)Pocket Obstetrics

Slide chart made for Dutch branded pregnancy test Planosec showing the pregnancy cycle in weeks/months from 1st day of last menstruation to expected date of birth    


POPE Valve Pins (AC-3.06)Electronics

Slide Chart made for Dutch lightbulb maker Pope (later taken over by Dutch electronic multinational Philips) for showing the 8-pin layout (a=anode, f=filament, g=grid, h= heated, k=cathode & i.c.= internally connected) of Philips valves + see later Philips version


PORTANJE (AC-4.17)Pocket Cardiology

Ruler made for defunct Dutch medical electronics company Portanje Elektronika & designed by F.A.M. Harms for analysing ECG printouts of cardiac Sinus Rhythms  - read more ….  


PRIMAP (AC-6.04c)Time/Conversion

Slide Chart version 04c made for Dutch paint company Primap Coatings for converting time across 7 times zones for 28 cities around the world


PTT DECIBEL (AC-1.42)Radio Electronics

PTT = Posterijen, Telegrafie en Telefonie or old Dutch post, telegraph & phone company & ​NL NR 04 - 2220 = ordering no. + see smaller sibling


PTT DECIBEL (AC-1.43)Pocket Radio Electronics

PTT = Posterijen, Telegrafie en Telefonie or old Dutch post, telegraph & phone company & ​NL NR 04 = ordering no. + see larger sibling


PTT RADIOLOGISCHE (AC-7.02a)Radiation

Slide rule/slide chart for calculating radioactive doses & intensities from a 1978 patented design (US4117315) from C.G.F. Amy & K.K. Keimpema+ issued as 4/8/1075/76346 by PTT = Posterijen, Telegrafie en Telefonie or old Dutch post, telegraph & phone company + see also large demonstration sibling


PTT RADIOLOGISCHE (AC-7.02b)Demonstration Radiation

Slide rule/slide chart for calculating radioactive doses & intensities from a 1978 patented design (US4117315) from C.G.F. Amy & K.K. Keimpema+ issued as 4/8/1075/76346 by PTT = Posterijen, Telegrafie en Telefonie or old Dutch post, telegraph & phone company + see also smaller but not small sibling


QUESTRAN (AC-4.16) Pocket Biology

Slide chart made for medicine trade name Questran for calculating number of daily doses of cholestyramine to reduce cholesterol - these days drug largely replaced by statins 


RADIOLOGISCHE (AC-7.01)Pocket Military Radiation

Slide rule/slide chart made for Dutch military personnel (NATO NSN no. 6665-17-055-1115) to calculate the effects & fall out directly after a nuclear explosion


Resistors & Capacitors (AC-3.04)Electronic

Slide chart with unusual construction & colour-coding for for choosing resistors & capacitors with appropriate values & tolerances 


Roulette (AC-1.nn)Gambling

Adapted 200 R with gauge marks as pay-out odds for 6 popular types of bets possible on the numbers part of a French style roulette table - reputedly conceived by Capt. Hans Feierabend  read more … 


SCHERING (AC-2.07)Agriculture

Slide chart made for defunct Belgium agrochemical company N.V. Schering S.A. for calculating the the appropriate use of pesticides when growing beetroot  


SHELL MESC 1962 (AC-2.04)Machining

Slide Chart made for Shell for normal & heavy-duty metal bolts per ASA & BS tables in inches & mm & according the Shell's Group 81 MESC (Material and Equipment Standards and Code) catalogue specification


SHELL VISCOKLOK (AC-1.40)Petroleum

Shell © clock (klok) design for calculating in 4 standard units viscosity of various oils at different temperatures - try out an online simulation created by Andries de Man


SIRKORSKY S-51 (AC-1.nn)Aviation - prototype

Rare load adjuster for an American helicopter + prototype possibly made for aviation branch of Dutch Navy (Marine Luchtvaartdienst - MLD) who nicknamed it Jezebel 


Spoorweglawaai (AC-7.04)Transport

Slide rule/slide chart for predicting overall railway trackside noise level in dB(A) according to several parameters e.g. noise screen, type & frequency of trains, average speed, etc - ALROPRINT 922130


ST 9-430/2 (AC-1.34a)Military Artillery Range Finding (1 of 2)

One of a pair of rules, without slides but with erasable cursors faces for hand-drawn pencil hairlines, made for the Dutch Army – the laminated (Alroderen™) paper tables & model # are ex-Army


ST 9-430/2 (AC-1.34b)Military Artillery Range Finding (2 of 2)

Two of a pair of rules, without slides but with erasable cursors faces for hand-drawn pencil hairlines, made for the Dutch Army – the laminated (Alroderen™) paper tables & model # are ex-Army


SYNRES (AC-2.23)Desktop Paint Conversion

​Slide chart converting viscosity values between various standardised units + SYRES = Dutch company (still operating) specialising in commercial coatings & resins for buildings, boats, cars, etc 


T.K.F. (AC-1.45b) Waistcoat Rietz

Specially commissioned 10 R for T.K.F. = Twentsche Kabelfabriek (Twentsche Cable Factory) was originally a cable manufacturer based in Dutch town Haaksbergen but is now a leading supplier of connectivity solutions


TEBODIN ANSI B16 (AC-2.13)Pipe Flanges & Fittings - fawn

Slide chart (in various colours) for designing cast meral pipe flanges & fittings according to ANSI standard B16 + Tebodin is an abbreviation for “Nederlandsch Technisch Bureau voor Ontwikkeling der Industrie” (Dutch Technical Bureau for Development of Industry) founded by Frederik van Iterson in1945  


TEBODIN ANSI B16 (AC-2.13)Pipe Flanges & Fittings - grey

Slide chart (in various colours) for designing cast metal pipe flanges & fittings according to ANSI standard B16 + Tebodin is an abbreviation for “Nederlandsch Technisch Bureau voor Ontwikkeling der Industrie” (Dutch Technical Bureau for Development of Industry) founded by Frederik van Iterson in1945  


TERONAC (AC-4.nn)Pocket Dietary

Slide chart made for registered brand name Teronac (generic name for slimming drug no longer normally available) to calculate an individuals Body Mass Index (BMI) based just on metric height & weight


TNO-IBBC (AC-7.07)Pocket Building Measurement - transparent

Ruler made for Dutch Organistie Voor Toegepast Natuurwetenschappelijk Onderzoek (TNO or Organisation for Applied Scientific Research) Instituut voor Bouwmaterialen en Bouwconstructies (IBBC or Institute for Building Materials & Construction) to measure cracks in walls   


Truck Tyre Performance (AC-1.20)Commercial Transport

 CJD monogram of company co-founder Dussel suggest an early model for determining large/heavy goods vehicle (HGV) tyre sizes + 3rd party Table of Truck Tyre Pressures in lid


Tubes MINIWATT Valve Pins (AC-3.07)Electronics - prototype

Slide chart possible made as prototype to show 8-pin layout (a=anode, f=filament, g=grid, h= heated, k=cathode & i.c.= internally connected) of Miniwatt range of valves + see later Philips production version


VALVO-RECHNER Transistors (AC-3.09)Electronics

Slide chart made for Germany company Valvo (when still part of electronic multinational Philips) for designing different low-frequency transistors


VAM (AC-5.05)Finance

Slide chart made for 40th anniversary of Dutch training organisation Stitching VAM (these days called Innovam & for cars) for calculating annual financial yield in Dutch Gulden for shops selling 100 to 700 bicycles/year  


VAN KRANENBURG (AC-1.46b)Waistcoat Rietz

Specially commissioned 10 R for Van Kranenburg a now defunct heavy machinery company based in Dutch city of Rotterdam


VERCOMBI (AC-2.24a)Machining

Slide chart for looking-up DIN & NEN standard sizes for nuts & bolts according to ISO & Whitworth standards + VERCOMBI refers to a joint purchasing company of the day for Dutch makers of screws & bolts Nedschroef & EWES  + see also sibling version


VICON 81982 (AC-2.05a)Agriculture

Slide chart with © design by Dutch supplier of farming machinery VICON (VIssers Construction Nieuw-Vennep) for calculating fertilizer distribution + see also sibling version


VOLMAC (AC-8.05)Work Flow - blue

Template/ruler (opaque) made for defunct Dutch IT company Volmac (later became part of Capgemini) for documenting with symbols processes & tasks which need to occur in a particular order


VOLMAC (AC-8.05)Work Flow - yellow

Template/ruler (opaque) made for defunct Dutch IT company Volmac (later became part of Capgemini) for documenting with symbols processes & tasks which need to occur in a particular order


VvS (AC-2.24b)Machining

Slide chart for looking-up DIN & NEN standard sizes for nuts & bolts according to Metric & Whitworth standards + VvS refers to a joint purchasing company of the day for Dutch maker of screws & bolts Verkoopkantoor voor Schroefbouten + see also sibling version


WeM (AC-1.nn)Rietz

WeM is part of alternative model numbering system + WeM = possibly Werktuig- en Machinebouw (mechanical engineering/machine industry) + possible forerunner to later (?) 200 R


WeR2 5 (AC-1.07b)Rietz

WeR2 is part of alternative model numbering system + WeR = possibly WeRktuigbouw (mechanical engineering) + suffix 5 possibly = version no. + possible forerunner to later (?) 100 R


ZYMA-NEDERLAND (AC-4.05)Nephrology

Nomogram made for defunct Dutch company Zyma-Nederland to help doctors by showing expected kidney renal function/performance levels for creatinine clearance & serum creatinine based on a patient's age & weight (n.b. underlying formulas now considered obsolete) 


Aristo
ModelTypeCommentsThumbnail
01068 Studio Desktop Technical/Log-Log

Extra wide ​- 25cm (no. 0968) & 12.5cm (no. 868) versions also made


01070 MultiLog Desktop Technical/Log-Log

Extra wide ​- Multilog v/s Studio = extra LL00 & LL0 scales - 25cm (no. 0970) & 12.5cm (no. 870) versions also made


101 Junior Demonstration OHP School/Technical

Overhead projector version for model 0901 - see also Classroom version - Junior = range for high schools


1055 Commerz IDesktop Business

Series of imperial to metric conversion gauge marks on lower front face - s-d-£ scale is folded - inch scale on back - 25cm (no. 955) & 12.5cm (no. 845) versions also made ​


1067 UDesktop Darmstadt

​inch scale on back


1067 U (D&P)Desktop Darmstadt

Co-branded D&P name in well of stock - ​inch scale on back


109 (D&P)Desktop Rietz

Co-branded D&P name in well of stock​


168 Studio Demonstration OHP Technical/Log-Log

Overhead projector version for models 868 & 0968 - Studio = range for more technical disciplines


206/1&2 BiScholarDemonstration School 35mm Slide Projection Set

44nd anniversary gift from Ros - boxed set of two lantern slides specifically for manual feed 35mm photographic slide projector - BiScholar = range where a Sine scale is included on stock & on slide - demo version of 0906


30050 Lindell "55"Desktop Transversal Planimeter

No slide - specially commissioned by Finnish stationers Ab Herman Lindell Oy - for measuring distances/areas - cursor extension suggests results were transposed for further working - name Herman Lindell + “import” & “copyrighted” in Finnish on the back


301 Junior Demonstration School/Technical

Later Classroom version for model 0901 - see also OHP version - Junior = range for high schools


303 LL Scholar Demonstration School/Log-Log

Later Classroom version for model 0903 LL - Scholar = general schools range


60126 RADAR-WINDDesktop Military Artillery Range Finding/Meteorology

Modern day mit Strichteilung version (inner scales calibrated in more military favoured 6400 milliradians or MILS) of High Altitude Calculator for German Armed forces (NATO NSN No.: 6660-12-140-6737) for global missile trajectories or possibly jet stream & its effect on missiles or planes flying at high altitude


670 NSUPocket Keyring/Time-Speed-Distance Travel Calculator

NSU = German motorcycle & later car manufacturer - conventional time-speed-distances for motorists with km/hour on front & metric fuel economy Litres/100 km on back + B&W version also made & sibling 671 model calibrated for imperial miles & gallons ​


890 RietzPocket Rietz

Compared to sibling twin model 89 has magnifying cursor & peripheral hairlines  


939 StalbetonReinforced Concrete - System Göttsch

Version for 1200 - 2600 range + Table of factors & pictograms on back


940 Stahlbeton (DIN 1045)Reinforced Concrete - System Göttsch

Extra wide body & very complex to use + Table of factors & pictograms on back


956 BildflugPhotography

Specialist model for aerial photography


99Demonstration/Display Rietz

100% Geretsried made dummy - slide does not slide - “Ausstellugsmuster” on back


99Demonstration/Display Rietz - early

100% dummy - slide indented but does not slide - “Ausstellugsmuster” on back


Aston & Mander
ModelTypeCommentsThumbnail
Hill'sArtillery for Indirect Fire

Arm length 26” scale, a table for fuse rating of 18pr for ranges <2000 yards, a Flight of Time (T of F) table in seconds/thousand yards & a synopsis of “Orders” on back


Aston, J.
ModelTypeCommentsThumbnail
Carpenter Timber No. 22060Joint 2-fold Tunnel-hinged Coggeshall

D GIRT line = 4–40 with IMPL GAL gauge point - unbranded but font & model numbering identical to known J. Aston + two-entry ½ & ¼ scale table on front + E & M scales (split over 2 legs) on back.


Aston, T
ModelTypeCommentsThumbnail
Hawthorn EngineerJoint 2-fold Old Arched-hinged Coggeshall

D Girt line = 4-40 + structural conversion & material gauge marks on front + “Extreme Strain” tables of material compression strengths & conversion measures on back


AstroCart
ModelTypeCommentsThumbnail
Eise Eisinga PlanetariumDesktop Astronomy - Northern Hemisphere

Slide chart made for the Eise Eisinga Planetarium (oldest still working planetarium) to calculate star positions & star signs for given date & time as seen from The Netherlands  


AWF (Ausschuss fuer Wirtschaftliche Fertigung)
ModelTypeCommentsThumbnail

SR 701Machining Time poly-slide (2) - early

made by Hans Seehase to design (1928-1930) by Friedrich Bahlecke - table of factors on back


SR 702Belt Performance & Belt Speed poly-slide (2)

made by Hans Seehase to design (1928-1930) by Friedrich Bahlecke


SR 704 Load Capacity of Springs

made by Hans Seehase to design (1930) by Friedrich Bahlecke - often used in combination with its SR 705 sibling


SR 710Bowing/Bending of Beams (metal or wood) poly-slide (2)

made by Hans Seehase to design (1931) by Friedrich Bahlecke - bottom scale = pictograms + Moment of Inertia table of constants on back


SR 715Rivets for Steel Construction

made by Hans Seehase to design (1931) by Friedrich Bahlecke & R. Jacki


SR 722Water Line Capacity

made by Hans Seehase to design (1934) by Helmut Lummert & Friedrich Bahlecke - according to Lummert formula


SR 726Gas Pipe Line Calculator for High & Low Pressure poly-slide (2)

made by Hans Seehase to design (1936) by Helmut Lummert - SG & Conversion tables on back


SR 751Blank but with hand-drawn scales for Machining

made by Hans Seehase - now part of the impressive AWF collection of fellow collector Karl Kleine


Baird & Tatlock
ModelTypeCommentsThumbnail
Richmond's ImprovedMilk

Retailed by Dairy Supply Co. Ltd. - designed by Henry Droop Richmond (1867 – 1931) for calculating milk yields according to lacto(hydro)meter SG readings & formula on back - where T = % total solids, G = specific gravity @ 60ºF & F = % fat


Bate, Robert Brettell
ModelTypeCommentsThumbnail
(NoName)Alcohol Proof

Unmarked but identified by Tom Wyman + layout on back merely extends range from front - possibly out of a Sikes Hydrometer set or modern replica


Berville, P.
ModelTypeCommentsThumbnail
(NoName)Pocket Mannheim

Probably made by MARC (OEM of No. 2) - inch scale & Werf Gusto. Firma A.F. Smulders, Schiedam on back


Billeter, Julius & Ernst
ModelTypeCommentsThumbnail
A1Basic
W 10Desktop Basic long-scale
W 4Desktop long-scale

Missing chrome turning knob - based on drum-based design patented in 1894 (US513172) & tradition of drum-type Swiss makers  


BIOMATE (UK) Ltd.
ModelTypeCommentsThumbnail
BiomateBiology

Patented design (GB1446576) by A.F. Green for finding biorhythms (for ages 1 to 80) for any given day of the year - late 19th century theory (no proven scientific basis) developed by German physician Wilhelm Fliess for 3 biorhythm cycles: physical (red 23-day cycle), intellectual (green 33-day cycle) & emotional (blue – 28-day cycle)​


Blundell Brothers/Rules Ltd. (BRL)
ModelTypeCommentsThumbnail
## Double SharpSteel Weight Calculator (Model A)

Made for James Austin & Sons, Dewsbury, UK - slide behind a window rather than closed frame - table of decimal equivalents of fractions in well of stock - steel bar & sheet conversion aids on back of slide & stock - see Skid Stick No. 10, February 2001


0552-160219Military Torpedo Bearing Rate (Mark I Model 0)

Naval instrument (6605) for British MoD (National Stock Number: 6605-99-462-3859) for calculating  gyro settings based on speed/angle/range for straight-running torpedoes


0552-160221 / P2297Military Torpedo Spreading poly-slide (2)

Naval instrument (6605) for British MoD (National Stock Number: 6605-99-462-3861) for calculating the optimum spread of straight-running torpedoes


304Academy Darmstadt

White end-braces on back of stock


308Academy Accountant's and Business

For per-decimalisation £,s,d (UK went decimal 1971)


310Pocket Academy Basic

Conversion fan table on back


644944 / P5284Radiac Nuclear Fission Products poly-slide (2)

Hazard-Detecting Instruments and Apparatus (6665) for British MoD (99) Stock Number (911-0027) © Admiralty Research Laboratory, UK for calculating external radiation doses + scales on front of slides for air contamination & on the backs for sea water contamination - RADIAC = Radio-Activity Detection, Identification & Computation - read more ….


6665-110060 (ver. NL)Radiac Nuclear Radiation Calculator No.1 for land

Smaller Dutch version for calculating radiation contamination on land in training exercises


6665-110117 (ver. NL) Radiac Nuclear Radiation Calculator No.1 for land

​Later larger Dutch version of 6665-110060 for calculating radiation contamination on land in training exercises


6665-99-911-0117/0060Radiac Nuclear Radiation Calculator No.1

Designed by William Orr (1951) + BRL Mod/NSN Nr.:6665-99-911-0060 made for British & Canadian Governments + intermediate & inner discs are double-sided: (i) pink for contamination over LAND & (ii) blue for contamination generated at SEA - centre split washer to flip sides


80543Omega Artillery Mils (MK2)

Fire Control Computing Sights and Device (1290) for British MoD - National Stock Number: 1290-99-960-0933 - Trig scales are in Mils (6400 mils = 360 degrees)


AG2Rietz-likeReplacement for G.2 model - tensioning pins in edge & cm scale on back
AL6Log-LogReplacement for L.6 model - tensioning pins in edge & inch scale on back
BlakeboroughValve Sizing

Model name = Joseph Blakeborough & Sons Ltd. - West Yorkshire engineering business (1866-1989) specialising in design & manufacture of industrial water valves - for choosing correct size valve based on a calculated flow coefficient


C24 DCost & Profit Reckoner Retail

Model suffix “D” denotes later model with all-plastic 1-piece moulded “Diakon” cursor


E.18 ElectriciansElectro

1 of 3 follow-on models replacing earlier E.3 Bakelite Electro - 2 slide tension adjustment screws on botton side edge + cm scale & patent no. 644944 on back


E.3Electro

Conversion table on back - Batch No. 299 + tensioning pins - read more ...


G.1 Student Enhanced Mannheim without Trig scales

Cheaper model with no stove enamelling on the back - Batch No. 533 + tensioning pins - read more ...


G.1 (reject)Student Enhanced Mannheim without Trig scales

Batch No. 101 - top front edges shaved off & “SUBSTANDRD” stamped in back - one of many as “waste rate” was +/- 50-60% of all production! - read more ...


G.2Enhanced Mannheim without Trig scales

Conversion table on back. Batch no. 1779 + tensioning pins - read more ...


G.2Enhanced Mannheim without Trig scales - early

Plain back - No batch no. - read more ...


G.5Enhanced Mannheim

Conversion table on back - Batch no. 365 + tensioning pins - read more ...


HolophaneAngle Lighting Calulator

Batch No. 1952 + tensioning pins - read more ...


HolophaneIllumination Lighting Calculator

Batch No. 655 + tensioning pins - read more ...


L.4Log-Log

Conversion table on back - Batch No. 316 - read more ...


L.6Log-Log

Company name “Taylor Woodrow”+ conversion table on back - Batch No. ?51 + tensioning pins - read more ...


LakerCutting Speed/Feed Calculator

Design copyrigh: Firth Brown Ltd - batch No. 249 + table constants & conversion factors on back - read more ...


P.8Pocket Mannheim

Conversion table on back - Batch No. 591 - read more ...


P.8Pocket Mannheim - early

Mottled/fading of enamel - Batch No. 337 - read more ...


P.8Pocket Mannheim - late

Conversion table + ICL COMBUSTION on back- Batch No. 1843 - read more ...


P1409Holophane Illumination Calculator

First order by Holophane Ltd. to replace the original two BRL lighting bakelite models: (i) Illumination Calculator & (ii) Angle Calculator - the possible inspiration for Blundell’s highly successful “P” series.


P1418Shell-Mex & BP Room Volume Calculator

Made for Shell-Mex/BP (SMBP) Ltd


P1442Shell-Mex & BP Friction Loss Calculator

Made for Shell-Mex/BP (SMBP) Ltd - conversion constants on back


P1454Pipe Flow

Made for ICI (no. 230) - nomograms and a table on the back


P1470Conversion

Slide chart for metric to imperial conversions made for: Loughborough Glass Co. + table of conversion factors on back - based on earlier M1759 design 


P1553Armstrong Calculator for Flooring

Made for Armstrong Cork Co. Ltd., London for calculating cost in sq. yards/feet to tile a floor area and/or the number of 9” x 9”/12” x 12”/18” x 18” floor tiles needed - grey end-braces on back of stock


P17Log-LogOne of replacements for P.8 model - cm scale on back
P1732/AFisher Valve Sizing Mark III F

Copyrighted French version made for Elliott Automation based in Paris


P1960/BPaint Calculator (folded £-s-d scale)

Made for Sissons Brothers & Co. Ltd., Hull, UK - grey end-braces on back of stock - spreading/coverage rates for types of Sissons’ household paints on back


P2245Textile

Slide chart for yarn count conversions made for Bentley Group, UK


P2304Paper Substance Calculator

Promotional give away made for commercial paper manufacturer & merchant: The Wiggins Teape Group, High Wycombe, UK for calculating length & weight of a reel for a given weight of paper (grams/m2 ) & width - grey end-braces on back of stock


P2327 (P4409)Percentage Overlap on Metal Seams

Made for Metal Box Co. (MB) - P2327 old no. for Halden version but MB version should be P4409


P2808Ultrasonic poly-slide (2) for testing metal buttt welds

Original training/testing version made for inventor J.W. Fox (Brit living in USA - hence American 1967 © design) & Schoool of Applied Non-Destructive Testing, London (SANDT) - design later sold to M. Falk & Co & a simplified version (using standard components & a duplex cursor) reissued as BH P4366


Paper Facts & FiguresPaper Calculating Rule

Unmarked reused Academy 300 series blank for Paper Facts & Figures Ltd. - © specialised scales/method for paper distribution calculations by paper buyers, estimators, etc. - unusually open frame construction scales also on back


S.101Pocket Rietz-like

No BRL branding but special commission (without trig scales) for motorsport company Charles Vandervell (CAV - that later became Lucas CAV)


T.12 TechniciansLog-Log

Unusual folded scales layout + two patented (GB644944) slide tension adjustment screws in bottom side edge + cm scale on back


T.20 Technicians Desktop Log-Log

No batch number but 4 tensioning pins & 4 chiselled out recesses in each end of top & bottom side edges to combat Bakelite shrinking problems + plain Bakelite back - read more ...


T.50Janus Multi Log-Log

Janus logo = dual-faced (future & past) Roman god of beginnings & transitions


U.7 UniversalLog-Log

Conversion table on back. Batch No. 609 + tensioning pins - read more ...


Blundell Harling Ltd. (BH)
ModelTypeCommentsThumbnail
0490.37Conversion

Slide chart for converting various imperial units into metric


0490.45Mixology

​Slide chart for mixing 44 different cocktails - possibly later reissued as P5225 & P5335 - with double no. of cocktails but uncannily similar to IWA version 


500Academy Log-Log

Includes highlighted yellow strips on cursor for reading off A/B & C/D scales on front & C/D scales on back


6665-99-780-8137Radiac Nuclear Radiation Calculator No.1 Mk2

Later variant of BRL Mod/NSN Nr.:6665-99-911-0060 version + intermediate & inner discs are double-sided: (i) pink for contamination over LAND & (ii) blue for contamination generated at SEA - centre split washer to flip sides


6B/1112682Hercules C.Mk.1 Aviation Trim Computer

Made for UK MoD & designed by H.O.A.S.C. Operation Research department of RAF - table of fuel movements on back


802Academy Log-Log
803Academy Rietz

B & C scales highlighted in yellow


812Pocket Classmate Academy Rietz
813Classmate Academy Rietz
904Academy Darmstadt

Same construction as Academy 800m series but with double-sided interlocking convex cursor


905Academy Log-Log

Same construction as Academy 800m series but with double-sided interlocking convex cursor


Allied ColloidsPocket Rietz

​Special commission for Allied Colloids - a UK speciality chemicals company


M5572Lilliput Conversion

Slide chart for metric to imperial conversions but made as a business card for BH Technical Director Peter Soole who joined the company in 1960


M899Pocket Electro Power Factor calculator

Slide Chart made for British Insulated Callender’s Cables Ltd (BICC) - © UKP/7M/262 on back​


NL 11-95Pocket Basic Memorial

1 of only 100 made especially for the IM1995 - the inaugural Int. meeting held in NL


P2734AFisher Valve Sizing Mark V

Copyrighted version made for GEC-Elliott Valves Limited


P3679Music Chord Computer

Slide chart specially commissioned by UK copyright holder Dudely Fulller Associates - design invented by musician Dudley Fuller


P4099Holophane Illumination & Angle Calculator (metric)

Last order by Holophane Ltd. to replace the original two BRL lighting bakelite models: (I) Illumination Calculator & (ii) Angle Calculator - the possible inspiration for Blundell’s highly successful “P” series.


P4463Holophane Illuminanace & Angle Calculator

Last order by Holophane Europe to replace the original two BRL lighting bakelite models: (I) Illumination Calculator & (ii) Angle Calculator - the possible inspiration for Blundell’s highly successful “P” series.


P4743Fisher Valve Sizing Mark VIII

Copyrighted version made for Fisher Controls


P4985Chemical

2-set slide chart (based on an old design) specially commissioned by METREC Metals Recycling b.v. for recycling non-ferrous metals


P5092Oil Fuel Viscosity-Temperature Calculator

Special commission by British Petroleum (BP) Trading Ltd. -  later P5128 sibling version with cosmetic differences


P5128Oil Fuel Viscosity-Temperature Calculator

Unbranded but clearly a BH special commission by British Petroleum (BP) - earlier P5092 sibling version with cosmetic differences


P5154Beer/Lager Retail Price Calculator

Slide chart made for Courage Brewery - front for draught/barrel beers/lagers & back for bottled beers/lagers - unusually it integrates the Value Added Tax (VAT)


P5527Roof Pitch Indicator

Slide chart made for Marley / Chestnut Roofing Supplies Ltd


P5731Music Note Tracker

Slide chart made for UK patent holder (GB2245409) Peter Davies.


P5798Pocket Dietary

Slide chart specially commissioned by Glubay to calculate an individuals Body Mass Index (BMI) based just on metric height & weight


P5939Conversion

Slide chart for imperial GBP prices to metric equivalents


P6290Refrigerant

​Slide chart specially commissioned by ALKLIMA/MITSIBUTI ELECTRIC for air condition units 


Robert Jenkins Co. LtdPocket Tank Capacity Calculator

Unbranded but identical to earlier BRL/BH “P” versions - design by Alan Menmuir -


S143-10School Rietz without Trig scales
S150-10School Rietz
S150-20Pocket School Rietz
W.H. Smith Student Log--Log

One of three generic BH-made models sold by UK retailer/stationer W.H. Smith


Booth, W. & Co.
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(NoName)Hatters Gauge

Retailed by an Australian General Drapers, Tailors & Outfitters - read more …


BOOTS / RINGPLAN
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StandardPocket Rietz-like

Bottom Inch scale inverted - OEM probably made  by FUJI (pocket model 535s) ​


Bradburn & Sons, T.
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Carpenter TimberJoint 2-fold Bradburn's Bolted-hinged Coggeshall

D Girt line = 4-40 + five-entry ¼ to INCH scale table on front + Lion trade mark + half-length E & M scales (split over 2 legs) on back


Brevetti Lanza
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AddimatWheel/Slide Adder

Original Italian model name: Addipresto. Only capable of addition. 


British Engraving and Nameplate Manufacturing
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Bonwitt 5403Log-Log

Maker only made 4 Bonwitt models - British Engraving (with Edward Holliday) granted patent GB618135 in 1949 for an engraving method - meaning of Bonwitt model name prefix unknown


British Slide Rule Co.
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The SupremeStudent Log-Log

Tables of conversion constants on back


The Technical StandardLog-Log

Tables of conversion constants on back


Burrows, W. & J.
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(NoName)Alcohol Proof

More likely retailer than maker + layout on back merely extends range from front 


Buss, Thomas Odempsey
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(NoName)Alcohol Gauging, Ullaging & Reducing poly-slide(2)

Front face for Gauging & Ullaging calculations & reverse side for Reducing & Stocktaking calculations + other known examples always part of spile rod set


Sikes' 42300Alcohol Hydrometer set

Scale runs form 0 -10 + full set of 9 brass weights (10 - 90) all stamped: 42300


Carbic Ltd / Otis King
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Fischer (or Fisher) Cylindrical CalculatorHelical long-scale

Invented & patented (GB778556) by Rafael Fischer in 1957 + full-length open ended plastic sleeve with 4 red positioning arrows & red endcap that works in conjunction with cursor sleeve


Model K 2nd versionPocket 07 helical long-scale white on black

Serial No. B1086 - both the presentation box & white on black paper scales are rare


Model K 2nd versionPocket 11 helical long-scale brass

Serial No. P2601 - brass sleeve probably only result of original black paint wearing off


Model K 2nd versionPocket 12 helical long-scale

Serial No. S0702


Model L 4th versionPocket 03 helical long-scale

Serial No. A8920


Model L 4th versionPocket 13 helical long-scale

Serial No. Z3168


Model NPocket 03 Retail & Monetary long-scale white on black

Serial No. 6998 - model, presentation box & white on black paper scales are rare


Casella, L.P.
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(NoName)Desktop "prototype"

Stamped CASELLA but possibly made by UK maker W.H. Harling - upside-down scales on the slide probably a design feature when inverting the slide - read more ...


Anderson ImprovedLong-scale extra precision

Three extended non-standard scales (Patent GB190309095 - Major F.J. Anderson) respectively folded 4/4/7 times for extra precision + “Supplied by W.H. Harling” blind-stamped in back + 778 stamped in left-hand side edge


Clements Newling & Co. Ltd.
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(1464)Hatters Gauge

OEM version made by John Rabone & Sons for well-known UK reseller - read more …


Co Atpress
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Het Ei van CoMusic Chords

Slide chart (later version) copyright designed & retailed by Co Atpress (“coat press” nickname = pseudonym for Kees Jaspers) for simply finding any chord on any string or keyboard instrument + Kees was a a bassist & member of Dutch bands Down Town Jazz Band, Dixieland Pipers & Dutch Swing College Band


Het Ei van CoMusic Chords - early

Slide chart copyright designed & retailed by Co Atpress (“coat press” nickname = pseudonym for Kees Jaspers) for simply finding any chord on any string or keyboard instrument + Kees was a bassist & member of Dutch bands Down Town Jazz Band, Dixieland Pipers & Dutch Swing College Band


Color Wheel Company
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3459 Watercolor WheelDesktop Colour Mixing - early

Slide chart (still sold) designed to assist artists in mixing watercolours & to achieve colour harmonies


CONCISE (K.K. Konsaisu)
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26APocket Enhanced Mannheim without Trig scales - early

Combined slide rule/slide chart specially commissioned by Japanese engineering company Chiyoda + conversion factors on back + removable data card with weight, length, square (area) & cubic/capacity conversion tables 


28Pocket Enhanced Mannheim without Trig scales

Specially commissioned by Japanese drawing instruments company Takeda + conversion factors on back + double-sided cursor is superfluous as nothing to calculate on back


32Keyring Basic/Perpetual Calendar

Printed Patent no. 479446 + perpetual calendar (only for 1960 to 1981)


600Pocket Chemical

Combined slide rule/slide chart designed by SAMA & ETANI & specially commissioned by Dutch oil major Shell +periodic table of elements on back + removable data card with length, area, weight, decimal equivalents, volume, velocity, flow rates, gas constants, energy & pressure conversion tables


CTCS-552Pocket Chemical

Combined slide rule/slide chart designed by SAMA & ETANI & specially commissioned by American chemicals company DOW + table of elements & temperature conversion chart on back + removable data card with length, area, weight, decimal equivalents, volume, velocity, flow rates, gas constants, energy & pressure conversion tables - CTCS model name prefix = Conversion Tables & Circular Slide Rule 


EE-112Pocket Electronic

Combined slide rule/slide chart designed by SAMA & ETANI & specially commissioned by American engineering company Brown & Root Inc. + reactance nomogram on back + removable data card with length, weight, area, volume, energy power & velocity conversion tables - EE model name prefix = Engineering & Electronic


Herman van HerwijnenPocket Stadia Topography

Specially commissioned memorial edition by defunct online group ISRG for late HvH (1929-2004) + lookup table for correcting distance measurements on front  


Contina AG / CURTA
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Type I Stepped Drum Calculator - System Curt Herzstark

Serial No.: 24587 designed by Curt Herzstark (1902-1988). Highly sophisticated calculating machine based on Leibniz's stepped drum concept - see also smaller Type II sibling.


Type IIStepped Drum Calculator - System Curt Herzstark

Serial No.: 545719 designed by Curt Herzstark (1902-1988). Highly sophisticated calculating machine based on Leibniz's stepped drum concept - see also smaller Type I sibling.


Controller Calculator
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(NoName)Waistcoat Mannheim-like - early

Notably has an inner K scale instead of usual B scale + 3 tables of conversion factors on back


110 RPocket Mannheim-like

Table of conversion factors on back


75 RWaistcoat Mannheim-like

Made for F. Krupp - fan chart of constants on back​


75 WWaistcoat Mannheim-like

Unusual “W” model & monochromic colour scheme + cube chart of conversion factors on back


Cooper, Charles T. & Sons (Ltd.)
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BachananPaper

Promotional gift by defunct wood UK pulp merchant Becker & Co. Ltd. for determining capacity/output of paper-making machines based on 1918 patented design (GB115207) by William Stanhope Buchanan + G. Clapperton name on front face probably refers to George Clapperton who wrote the definitive manual for paper-makers & owners of paper mills + inch/cm scales & Lbs Demy to Lbs DblCern conversion scale on back


COX & STEVENS Aircraft Corp.
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V (M.L. Navigatie-Doos)Boxed Aviation

1946 patented design (US2405803) for marine aircraft dead reckoning by Arthur L. Thurston for Dutch market + innovatively built into metal box with switches to change form of calculation (e.g. from flown course to course over ground) with wind, barometric & temperatures scales & speed dial inside lid + wind direction dial, various speed & optional settings & refinements (e.g. degrees of drift) built into main body of box


Danfoss
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(NoName)Pocket Refrigerant - early

No slide


(NoName)Refrigerant

No slide


520H4713RefrigerantNo slide
CalculatorHeating flue gas lossesCalculations based on a standard calorific value of fuel oil - back of calculator gives fuel oil nozzle capacities
RT.00.A1.00 RefrigerantNo slide
RT.00.A2.00RefrigerantNo slide
RT.0X.A5.00RefrigerantNo slide
DARGUE Bros. Ltd. / Simplon
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BilateralLog-Log - early

“Half-duplex” layout with scales on back of closed frame stock & extra-wide cursor track for reversing cursor - unmarked & early version of S.B.10 because patent (GB413308) is still pending - read more ...


S.B. 5 Bilateral Pocket Enhanced Mannheim - early

“Half-duplex” layout with scales on back of closed frame stock & reversible cursor - pocket version of S.B.10 with LL scales - early version because patent (GB413308) is still pending - read more ...


S.B.10 BilateralLog-Log

“Half-duplex” layout with scales on back of closed frame stock & dual cursor tracks for reversing cursor - read more ...


S.E.10 (Bilateral)Electro

“Half-duplex” layout with scales on back of closed frame stock & dual cursor tracks - W & V scales in well of stock - degree (<5˚34’) Tan & degree (70˚-90˚) Sin look-up tables on back of extra wide non-reversible slide with chamfered edge cursor as part of well + table of conversion factors on back - read more ...


S.M.10 Major (Bilateral)Log-Log

“Half-duplex” layout with scales on back of closed frame stock - chamfered opening used instead of reversible cursor - degree (<5˚34’) Tan & degree (70˚-90˚) Sin look-up tables also on back of non-reversible slide - divisions on 2 & 1 cycle A & D on back of stock run from 0.01-0.1-1.0 & 0.1-1 + table of conversion factors on back - read more ...


S.P. 5 PrimaryPocket Mannheim

Pocket version of S.P.10 but without LL & CI scales - extensive table of conversion factors on back - read more ...


S.P.10 PrimaryLog-Log

Extensive table of conversion factors on back - read more ...


S.R.10 BilateralRietz

Later “Half-duplex” layout with scales on back of closed frame stock & extra wide single track for reversing cursor - read more ...


SR-2Pocket Mannheim

Unusual dirty orange colour plastic = form of bakelite - same as SR-1 except with full-view glass cursor & sturdier construction - unusually with original case ​- read more ...


SR-3Pocket Uniface Technical

Unusual dirty orange colour plastic = form of bakelite + aluminium strengthening strip on back - “Uniface” type (S & T scales being on front face instead of back of slide) is an innovation others would follow years later - read more ...


SR-5 Uniface Technical

Unusual dirty orange colour plastic = form of bakelite - full version of SR-3 + “Uniface” type (S & T scales being on front face instead of back of slide) is an innovation others would follow years later - read more ...


SR-6Enhanced Mannheim

Unusual dirty orange colour plastic = form of bakelite - slide not reversible but 2 windows in the back & aluminium strengthening strip - read more ...


WR-6 StandardEnhanced Mannheim

De-Luxe model with plain white celluloid faced slide & back + cm scale on back - 1 of 5 WR models with higher quality finish & higher retail price - read more ...


WR1-A SelectaMannheim

Plain white celluloid faced slide & back - 1 of 5 WR models with higher quality finish & higher retail price - read more ...


XL-10 (Bilateral)Log-Log

Later reissued version of S.B.10 with divisions on 2 & 1 cycle A & D on back of stock redrawn to run from 0.01-0.1-1.0 & 0.1-1.0 + famously named Fastest slide in the Whitehall by Arthur C. Clarke - read more ...  


Datalizer Slide Charts Inc.
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Chord BoardMusic Chord Finder & Key Transposer

Slide chart copyrighted design by Martin H. Samuel - later replaced by a phone App


David (Emile)
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CalculimetreWatch Charpentier Mannheim

Wonderful 40th Wedding Anniversary present from Ros - made by Charpentier 


David Chandler Co.
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The Night SkyDesktop Astronomy - Southern Hemisphere

Slide chart to calculate star positions & star signs for given date & time + designed to be read at night


Dennert & Pape (D&P)
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14Electro

cm scale in well + 3 adjustment screw in bottom side edge


D 2/28Enhanced Mannheim - early

Railway track scales + cm scale & D&P D.R.P. no. 126499 in well & 3 adjustment screws in bottom side edge +- conversion table & 2 open windows on back


D 2/28Enhanced Mannheim - short

Short stock length (possibly because shortage of raw materials) with railway track scales + cm scale & D&P Altona & “Patent” in well of stock - conversion table + 2 open windows on back


D 9/28Rietz

3 adjustment screws on bottom side edge - conversion tables on back


DUPA D14.15Pocket Electro

Company NAW & model details in well & 2 adjustment screws in the bottom side edge + table of conversion factors on back ​


DUPA Line Loss & Voltage Drop CalculatorElectro poly-slide (2)

Copyrighted & patented (US1560599) by Charles C. Moler in 1925 - special commission for The Potomac Edison Company, Maryland, USA (Moler’s employer) ​- 4 adjustment screws in top side edge - besides preventing voltage flicker on electrical distribution lines it could save money by avoiding expense of higher grade of cable when not needed - read more ....


DUPA S.90Rietz

Possibly an early special commission for H. Linke - PERTODO = D&P trademark for free-view cursor (they wanted RERTOTO from the Latin word “totus” but had to change to PERTODO) - 4 adjustment screws on bottom side edg​e - conversion tables on back


GWRDesktop Military Naval Artillery

Instruments for German armed forces during WWII used codes to hide maker’s identity - gwr​ = D&P + besides solving normal artillery-related distance problems, this naval version also takes into account drift of a moving vessel


IEnhanced Mannheim

Table of conversion factors on back


ILilliput Enhanced Mannheim

D&P in well + ​Inch & cm scales on back


IPocket Enhanced Mannheim

cm scale & D&P & D.R.P. No. 126499 in well of stock


IPocket Enhanced Mannheim - early

D.R.P. No. 126499 in well of stock + inch & cm scales on back


IVDesktop Enhanced Mannheim

IV = model with 4 adjustment screws in bottom edge - railway track scales - cm scale in well of stock​


Präzisions-Kubus-RechenstabSquaring long-scale

Uncommon & unusual model with just root & trig scales (all long scales) - one open window with cursor line in back on right​ ​


QR 41Desktop Military Artillery Squaring

QR = “Quadrat-Rechenschieber” - commissioned by “Gebr. Wichmann” (stamp in well) - probably classroom training aid for anti-aircraft gunners - layout consists of two pairs (upper set 0 - 50 & lower set 0 - 15.8) of non-logarithmic independent root scales (no interaction) derived from a set of tables by German Peter Timpenfeld & first published in 1888​ - non-conventional use of a cursor purely for positional summing of the squared values


S 6/28 (System Rietz)Rietz

DRP No. 126499 in well of stock & 3 adjustment screws in bottom side edge + conversion tables on back​ + 1 cursor window


DEVCO
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Tel-A-ChordMusic Composition & Transposer

Slide chart design by Victor Leone for accordion playing


Diefenbach
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WMNPocket Pipe Flow - System Mulder

For water pipes & WMN = Dutch water utility company  Waterleidingbedrijf Midden-Nederland + table of flow factors/speeds for various pipe/conduit sizes on back


Dietzgen
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1752P ManiphaseDesktop Rietz-like

Going by style of π gauge mark probably made by D&P + slightly longer slide + 6 adjustment screws & conversion table on back + Maniphase = Dietzgen​ name for an extended Enhanced Mannheim layout 


1767P NationalEnhanced Mannheim

Possibly OEM by Charvoz-Roos or Festus + conversion table on back & 1 cursor window


1768-P ManiphaseRietz-like two-tone

OEM made in Japan probably by FUJI + Maniphase = proprietary​ name for extended Enhanced Mannheim layout 


1768P RelianceEnhanced Mannheim

Identical to Charvoz-Roos SR-105M + Table of Equivalents on back & 1 cursor window 


1769P FederalEnhanced Mannheim

Table of conversion factors on back & 1 cursor window


1771 RedirulePocket Enhanced Mannheim

Specially commissioned by Dutch heavy industry manufacturer Combinatie Pletterij-Nederhorst but OEM made by Bruning


1797A AtlasDesktop Business long-scale - Type III

Affectionately known as a “circular Gunter” - OEM version made by Gilson with novel clutch design & two cursors meaning a single D scale (effective length: 1067 cm) was sufficient + Trig scales + fraction/decimal conversion scale on back act as lookup “tables” 


Dimier
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ElectricPocket ElectroW scale in well of stock - COMPAGNIE GENÉRALE D'ELECTRO-CÉRAMIQUE & cm scale on back
Disney (Walt Disney Productions)
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Mickey Mouse Child's Disney World Teaching Aid/Calculator for Simple Arithmetic & Conversions

Child’s arithmetic slide calculator - made in Hong Kong - identical but later version known as: “Mickey Math Slide Rule”​


Slide Matching Child's Teaching Aid/Toy Puzzle poly-slide (3)

Made by MARX in Hong Kong - tile matching toy puzzle in form of slide rule featuring 8 vintage & much loved Disney characters


DIWA (Dansk Industri Waterpas A/S )
ModelTypeCommentsThumbnail
1-1 Rietz-IdealRietz

Called Ideal  because full complement of Trig scales included on front face


101 Log Log Log-Log

Veneers attached with screws/pins + table of conversion factors on back with 1 cursor window


201 Technical (ver.1) Rietz

Veneers attached with screws/pins + table of conversion factors on back with 1 cursor window


201 Technical (ver.2)Rietz

Veneers attached with screws/pins + table of conversion factors on back with 1 cursor window


301 CommercialEnhanced Mannheim

Veneers attached with screws/pins + table of conversion factors on back with 2 cursor windows


301 RietzRietz

Table of conversion factors on back with 1 cursor window


501 RietzRietz

1 cursor window in back


551Darmstadt

Unusual layout


601Pocket Promotional Rietz

Version of 621 but primarily a model for a promotional slide rule - in this case for Danish supplier of light-weight concrete SIPOREX + company details on back with 1 cursor window


601-1Pocket Rietz

Later version of 601 + 1 cursor window in back


611Pocket Electro

V and W scales in the well of the stock + 1 cursor window in back


621 TechnicalPocket Rietz

1 cursor window in back


631 CommercialPocket Enhanced Mannheim

Specially commissioned by Swedish company Elektromekano & printed on back + 1 cursor window in back


701Rietz

A “cheaper” model (all scales on front face) for schools + inch scale “upside down”


710 TeknilogTechnical

Impressive complement of scales but possible OEM by Japanese maker Ushida Yoko


741 Businessman ExportTechnical two-tone

From construction, two-tone nature, scale layout, & cm + inch scale on back OEM by Japanese maker Ushida Yoko


Draftwell
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1005Rietz-like

Draftwell probably OZ or NZ-based office supplies reseller - OEM by FUJI but retailed through Hope Slide Rule Mfg. Co. - slide coloured green on front


Dring & Fage
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(NoName)Alcohol Gauging poly-slide(2)

Post 1824 imperial based units/gauge marks + front face bottom slide can be slotted in alongside top slide (hence it only runs to 9.5) for double length i.e. Everard-like + considered by fellow collector David Riches Missing Link between square Everard design & follow-on duplex models - read more ...


(NoName)Desktop Alcohol Gauging

Post 1824 because of IM B & IM G gauge marks signify change from Winchester to Imperial based measurement - bottom Seg Ly. scale is for gauging when the cask is lying on its side


Carpenter TimberDesktop Coggeshall

Rare duplex Coggeshall with 4–40 GIRT LINE for volumes of round timber + 2 sets of brass gauge pins (marked 0,16, 8 & 8,16, 0 respectfully) for round, 8 or 16 sided timber + INVERTED LINE (AI scale) for volumes of rectangular timber - compared to Langley version layout front & back reversed


Customs & Excise 482Alcohol Saccharometer

​Scales run from 55 to 70 (1055/1070)


Customs & Exercise D-F-52Desktop Alcohol Gauging Head Rod

Seg Ly. scale on front face is for gauging when the cask is lying on its side + SPH’D scale on back face is for calculating the spheroid


Everard4-sided Alcohol Gauging poly-slide(4)

Makers No. 248 + pre 1825 because of Winchester based units/gauge marks + back of slide Face “A” = Divisors for various liquids + back of slide Face “B” = scales for correcting calculations for spheroid casks & other models + back of slide Face “C” = more Divisors + back of slide Face “D” = gauge points for various liquids


Mark VI Desktop Artillery for Indirect Fire

Serial no. = 36 - called Apparatus for the Observation of Fire was intended for use by lance-corporals & corporals in the field & not on a desk - issued by Min. of Defence (inventory no. 302SB) ​


DUVAL, Roger
ModelTypeCommentsThumbnail
(NoName)Desktop Rietz

Little known French maker (Drancy, Paris) - plastic models similar to Graphoplex - unusual wide body + top LL scale not standard for a Rietz making the layout somewhat unconventional


ElectroExtra-wide-Electro

Little known French maker (Drancy, Paris) with plastic models similar to Graphoplex + unusual extra wide body & striking monochrome scales + W & V scales in well of stock


E. Gundlach AG
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Diamant-KalkulatorJewellery Rotary Wheel

Slide chart specially commissioned by Hamburg Diamanthandelsgesellschaft Lenzen & Stormer & Amsterdam diamond dealer H.E. Slijper - calculates relationships between: (i) quality of a diamond, (ii) size in carat (weight), (iii) diameter in mm, (iv) price/carat in DM & (v) price/stone (total price) in DM  


Ebmeyer, H.W.
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TaremaSlide Adder

TaReMa model name = TaschenRechenMaschine or ​pocket calculating machine 


ECOBRA (Bayerische Reisszeugfabrik)
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(NoName)Pocket Cabling

​Special commission for Glasfaser M.B.H., Dusseldorf - company NAW on back


1461Pocket Rietz
R141Pocket Rietz

OEM model by FUJI


R154 COSMOSTechnical/Log-Log

OEM model by FUJI + green rubber feet 


Educational Novelty Co.
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"Consul" The Educated Monkey Child's Teaching Aid/Calculator for simple arithmetic

Invented & patented (US1188490) by William Robertson in 1916 - “Consul” = name of famous performing monkey of the day - set x & ÷ problems with feet - results framed by monkey’s hands ​(+ & - problems need Addition Table card)


Engineering Instruments Inc.
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(10-B) Book with Enhanced Mannheim without Trig scales

Cadillac Publishing Co. with give-away unmarked “10-B” with vol.1 of their Self-Teaching Encyclopaedia


10-B (unmarked)Enhanced Mannheim

Conversion Tables on back


10-B (unmarked)Enhanced Mannheim without Trig scales - monochrome

Conversion Tables on back


10-BKEnhanced Mannheim without Trig scalesStandard Lawrence 10-B but called 10-BK with conversion tables on back
250-BTEnhanced Mannheim

Conversion Tables on back


250-BTEnhanced Mannheim - early

Conversion Tables on back


250-BTWINSCO Enhanced Mannheim

WINSCO Wabash Instruments & Specialities Inc. on back + - Tables of Constants 


250-V (ver. 1)Enhanced Mannheim

Conversion tables on back


250-V (ver. 2)Enhanced Mannheim

Identical to ver. 1 but promoted in different colour box + Conversion Tables on back 


5-BPocket Enhanced Mannheim without Trig scales

Unmarked “5-B”


5-B LearnerPocket Student Enhanced Mannheim without Trig scales

Specially commissioned by Lakeside Toys +  DRAFT-A-PLAN BY LAKESIDE printed on rule


77A American Log-Log

OEM rule made by American maker ACU-Math (model 150) - unusual layout means the back is often mistaken for the front


Draft-a-Plan kit (5-B)LAKESIDE boxed set

OEM collaboration between Lakeside & Engineering Instruments


Engineering Mfg. Co.
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Calc-SlideEnhanced Mannheim without Trig scales

strange raised wings of the cursor design


EURATOM
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Brinck - De WoldeGeochemical

Complex rule invented by Dutchman Herman de Wolde & based on field work by Dutchman Johan Brink for calculating the probable of presence of metal deposits world-wide  - 1 of only 5 ever made


Fang Yuan
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212Pocket Enhanced Mannheim

Missing “square circle” logo + metal backing plate & 1 cursor window with + 1 hairline in back


Farmar, F.C.
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Publicans' RuleStandard for Licensed Victuallers

No. 1075 with early Liverpool address for helping publicans/innkeepers calculate over/under proof alcohol, gauging, blending, stocktaking, discount and profit + altimeter top-edge cm scale for height of liquid in a standing bottle + special C scale when used with either D, E, or F = amount of liquid in a barrel + G & H scales & reducing scale = amount of water to add to reduce alcohol strength (proof) or amount of spirits to add to raise alcohol strength + I & J scales give value of spirits if alcohol strength is raised or lowered + I & K scales = profits or discounts on sales/cost


Wine & Spirit Merchants RuleDesktop Standard for Wine & Spirit Trade

Trade rule calculating over/under proof alcohol, gauging, blending, stocktaking, discount & profit + later Gloucester Terrace address = possibly made by Lucas


Farrow (James)
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The EASY Slide RuleArtillery Range Finding

Designed and patented (GB117318) by Capt. Albert Charles Chew, British Royal Artillery


Fearns Calculators
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A13 Circular Slide RuleLog-log

LL scale to base 10 - tables of conversion factors on back


A14 Circular Slide Rule / Conversion CalculatorLog-log Conversion

Front identical to model A13 but in separate part of wallet interchangeable extra outer disc with different conversion scales


Farmer's Weekly Metric ConverterConversionFarmer’s Weekly is a magazine started 75 years ago for farmers & agricultural businesses & is still being published weekly - conversion C & D scales double-up for simple multiplication, etc - extra conversion tables on both sides
Fenwick Dew Point & Relative Humidity CalculatorWhirling or aspiratted hygrometer humidity Special commission for Fenwick Inspection Services Ltd., Southampton - 2 look-up windows in top disc
RS Stock No. 620-547 (A6)Screw Thread Metric Converter

Special commission for Radiospares (RS), Australia - a company still operating 


Fearns, Mear & Co.
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AUDCO Pipe Flow CalculatorPipe Flow

Designed by Norman Mear for Auderly Engineering Co. Ltd (AUDCO) for calculating turbulent pipe flow of liquids & gasses + parts engraved by United Chemical Engraving Co. before assembled in-house & back used for calculating Reynolds No. 


Festus Mfg. Co. / Acu-Rule Mfg. Co.
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Acu-Math 150Log-log

Unusual layout means the back is often seen as the front - identical to 150A except here end-braces added for extra rigidity & cursor is adjustable


Acu-Math 4Student Enhanced Mannheim without Trig scales
Acu-Math 401Student Enhanced Mannheim

Having Trig scales on front face was supposed to make it easier to use - moulded cursor bought in from American Molding Co., St. Louis - cursor tension spring bought in from Midwest Spring Co., St Louis


Acu-Rule 10-DEnhanced Mannheim without Trig scales

Often mistakenly thought to have been made by Lawrence - table of equivalents on back


Acu-Rule G-W PhotoPhotographic

Specialist model (G-W = designers C.G. Goodchild & L.V. Whitney) for photographers for calculating a comprehensive set of photo-related of camera settings + retailers AREL Inc. sole distributors - table of ASA film speed indexes & photography tips on back


Acu-Rule MR700 Mu-StickMusic Chord Finder & Key Transposer

Unlike any other Acu-Rule or music type - design copyright Mel McSwain - sole distributor: McSwain Co., Arkansas


Acu-Rule Van NostrandEnhanced Mannheim

OEM for retailer & publisher: D. Van Nostrand, New York - table of equivalents on back


Acu-Rule Yoder 103Enhanced Mannheim

OEM for Yoder Instruments, Ohio (related company : Lafayette) - table of conversions on back


Festus (100)Enhanced Mannheim without Trig scales

Same stock as later Acu-Rule model 100 - table of equivalents on back - possibly transition model with paper (edges + back) & painted (front) scales


Flying Fish (Shanghai Slide Rule Factory)
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1002 (ver.2)Electro Hyperbolic

Fawn end braces + unusual layout of scales


Fowler
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Junior (4MJRG1)Pocket Concentric long-scale

Unusual serrated revolving discs & only non-watch type Fowler made + on both sides​ many gauge marks around outermost/peripheral ring


Long Scale Calculator (2MG2) Pocket-Watch Concentric long-scale - early

Serial No. 14075 stamped in bulls eye on back - two milled winders - many gauge marks around outermost/peripheral ring on both sides


Magnum (4MG1)Pocket-Watch Concentric long-scale

Two milled winders - many gauge marks around outermost/peripheral ring - plain black back​


Twelve-Ten (3MG2)Pocket-Watch Business - early

Serial no. 330 with Bakelite back is 1st of 3 model variants + model name derived from C scale divided into tenths & 2 x D scales divided into twelves to help with decimal & duodecimal calculations - various gauge marks around outer rim 


Type B (3MT1)Pocket-Watch Textile - early

Two milled winders (one missing crown ring) - many textile-based gauge marks around outermost/peripheral ring - plain chrome back


Type E1 (2CTb2)Pocket-Watch Textile

Serial No. 4404 - two milled winders (one with crown ring) - many textile-based gauge marks around outermost/peripheral ring - table of weaving-related factors on back


Type T (2AT1)Pocket-Watch Scientific Publishing Textile

Early pre Fowler + prominent axle & two (1 ringed) crown winders & replaced by Fowler's Type M - tables on back


Fuji Keiki Mfg. Co. Ltd.
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106Technical two-tone
1200 01 (ver. 2)Darmstadt-like two-tone

4 plastic/rubber feet on back


125 BTechnical two tone

Appears strangely identical to model 106 except Fuji name is in italics & back braces are coloured green  


1250 S (ver. 2)Log-Log two-tone

4 plastic/rubber feet on back


535 SPocket Enhanced Mannheim two-tone without Trig scales
F-100Technical two-tone
Gamma
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2503Budapest Darmstadt

Company founded in Hungary in 1920 but may have started with OEM rules from UK maker A.G. Thornton as the style of the pi & telltale 8-pointed star marks on the box with Gamma name & logo suggests it is an early Thornton/PIC-made rule.


Gebr. Wichmann
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1418 R IIIRietz

​OEM by Nestler - cm scale in well - table of constants on back + 2 cursor windows


1425Enhanced Mannheim

OEM by Nestler - cm scale in well - table of constants on back + 2 cursor windows


1427Rietz

OEM by Dennert & Pape - D&P + DRP No. 126499 in well of stock + conversion tables on back​ + 1 cursor window


1919RDesktop Rietz

OEM by Nestler - cm scale in well of stock + hand-written list of formulas on back


431Mannheim

Model from the earliest known series​ - table of conversion factors on back


4429School Rietz

OEM by Faber-Castell with cm & inch scales on back + 2 cursor windows


4430Pocket Enhanced Mannheim

OEM version made by Dennert & Pape + cm & reversed inch scale on back + 2 cursor windows


4477Darmstadt

OEM by Faber-Castell with cm scale in well + 2 cursor windows in back


DrieskalenRietz

OEM by Nestler - table of constants on back + 2 cursor windows


Geo. W. Richardson
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1776Direct Reading Polymetric Rietz

Keyholes (top left & bottom right) are direct reading line-up points for a table of codes on the back. By aligning a chosen code in the keyhole the slide is automatically set for the chosen calculation. Provisional patent no. 1-31-11 on slide - full patents = 1911 US982876 & in 1912 US1021484 .


812Direct Reading Enhanced Mannheim

Keyholes (top left & bottom right) are direct reading line-up points for a table of codes on the back. By aligning a chosen code in the keyhole the slide is automatically set for the chosen calculation. Provisional patent no. 3-26-12 on cursor - full patents = 1911 US982876 & in 1912 US1021484 . ​


Slide Rule Model of 1917Desktop Artillery Range Finding

Robust military grade OEM for J. H. Weil & Co. - Trig scales are in Mils (6400 mils = 360 degrees)​


George Philip & Son Ltd.
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PlanisphereAstronomy - Northern Hemisphere

Slide chart to calculate star positions & star signs at latitude 52½º North for given date & time


GILL, Thomas & Co.
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Sikes' 67552-rule Alcohol Hydrometer set - temperature correcting

Layout on back of Proof rule merely extends range from front + 2nd Comparative rule is for calculating temperature corrections + hydrometer scale runs from 0-10 range + partial set of 8 brass weights (10 - 90 but 30 missing + cap) all stamped: 6755 but 2 from Dring & Fage + thermometer by Dring & Fage


Goliardo
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(NoName)Pocket Mannheim

Little known Italian maker/reseller


Gordon, A.M.
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Scale of Power & SpeedShip design/construction

One of a set of 4 such rules designed by Glaswegian Alexander Milne Gordon (1870’s-1922) M.I.N.A.


Graphic Calculator Co.
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Foxboro Vortex Flowmeter Sizing GuidePipe Flow (steam & gas)Specially commissioned slide chart but with slide rule operations & cursor - front for steam - back for gas - table on front
Graphoplex
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(NoName) 615Pocket Rietz - early

Early because lacking model no. + red outline of logo​ - longer than usual for pocket - two open windows with cursor line in back


(NoName) 620Rietz - early

Early because milky white original plastic + lacking model no. + red outline of logo​ - two closed windows with cursor line in back + table of constants om back


1600School Rietz C.A.P.
1600School Rietz C.A.P. - blue bands

Grey plastic case denotes a later model - “easy reading” blue banding for A/B & C/D scales ​


1612Pocket Rietz - early & all black

one open window right with 1 hairline in back - black logo = early model


1614Demonstration School Log-Log

Does not have cm top edge scale on standard 25cm 1614


1614School Log-Log C.A.P.
1694Technical
16ooSchool Riez C.A.P. - early & all black

Note mixed alphanumeric 16oo model no. - layout different to standard/later 1600 Rietz - black logo = early model​


604Typography Cicero printing

Ruler with cursor conversion aid + Cicero (old French thumb unit of measure = 27.07mm) is a typographic unit similar to a pica but with 15th century origins​


612Pocket Rietz

one open window right with 1 hairline in back


615Pocket Rietz

Slightly longer than the 612 - one open window right with 1 hairline in back​


620 (ver. 5)Rietz

One closed window right with 1 hairline in back​


620 d (ver. 1)Rietz

Model no. on back of slide - one open window with cursor line in back on right​


6245Desktop Electro Log-Log

Two closed windows with cursor line in back + see also smaller 643 sibling


6250Desktop Rietz

​Late model as colours have sweated or bleed because cheaper methyl ethyl replaced phenol as etching agent - two closed windows with cursor line in back


630Geometre Stadia Topography - 400g early

Missing model no. - table of conversion factor on back + one open window with cursor line in back on right


640Electro Log-Log

One open window with 1 hairline ​in back


643Pocket Electro Log-Log

Name of NL company Ingersoll-Rand in well of stock - one open window right with 1 hairline in back = see also larger 6245 sibling


647Darmstadt

Unusual inclusion of AI scale ​


650Pocket Electro

§ scales = 2-part COS scale - unusually for Electro’s W & V scales on front face ​


680 STATOS Reinforced Concrete - System Lüthy/Nussbaum

Patented design (CH314378) by Peter Lüthy & Max Nussbaum - § scales for N = 10 - Co. name MONTEFERNO, Bodio (CH) in well & on back - table of constants on back


681 STATOSPocket Reinforced Concrete - System Lüthy/Nussbaum

Patented design (CH314378) by Peter Lüthy & Max Nussbaum - § scales for N = 10 - Co. name MONTEFERNO, Bodio (CH) & table of constants on back


690 (ver. 2)Neperlog Log-Log

Impressive layout of 25 scales - Neper or Np is a logarithmic unit of measurement of physical field & power quantities + see comparable sibling model 690 a


690 aNeperlog Log-Log

Impressive layout of 26 scales - Neper or Np is a logarithmic unit of measurement of physical field & power quantities -+ see comparable sibling model 690 - comparable to ARISTO 0968


694 aTechnical/Log-Log
CALTEX Petroleum Rietz

Same model rebadged for TEXACO & ​CALCRUDE - red outline of logo = early - bizarre cursor design - °F & °C scales in well of stock - back of slide has American Petroleum Institute (API) crude oil gravity scales - table of constants + CALTEX logo on back


DYNSTAT Desktop Impact Testing

DYNSTAT is a mechanical impact/resilience testing method popular in Germany (DIN 53435) for testing small samples of plastic ​


EDF 355.145Electrical Power Cables

EDF = Electricitè de France - identical to model EDF 35 11 408 - table of values for single-phase lines in well of stock​ - table of maximum permissible intensity values on back


FLEXIMAXSteel Beams - System Potzsch/Demulder/Gajac

For calculating steel beams according size, weight, profile, etc based on formulae from Potzsch/Demulder/Gajac + two full-width open windows with cursor lines in back


Gaz de France 65-TX-01Pocket Gas Pressure/Flow in Pipes & Ducts
KOH-I-NOOR 10020Technical

Part of series for Czech stationer KOH-I-NOOR - copy of model 1694​


Meteo No. 2Meteorology - early & all black

Simpler version of two Meteo models ​for weather forecasting - distance scales in both imperial & metric - black logo = early model


Panneau PublicitaeDemonstration/Display Log-Log

100% dummy - scale layout printed on sheet of plastic as shop window advertising item - also made half-size version​


REVACOHydralic/Pipes/Valves flow rates

Made for CONTROLEXACT (later version II for COMSIP AUTOMATION) - for calculating flow (liquid & gas) in valves & flowmeters - REVACO = registered trademark - unusual layout/design & striking cursor


REVACO IIHydralic/Pipes/Valves flow rates

Made for COMSIP AUTOMATION (original version for CONTROLEXACT) - for calculating flow (liquid & gas) in valves & flowmeters - REVACO = registered trademark - unusual layout/design & striking cursor


ROPLEXRietz

Designed for rapid & accurate calculating - circular but housed in square case - front & back shown as per instructions - slide also worked by metal wheel - table of gauge points in centre​


SHELL (ver. F)Pocket Heating Oil Central Heating Efficiency

Uniquely slide is part of closed frame (no cursor) on back of stock​ - registered design commissioned by Shell Nederland Verkoopmaatschappij (SNV) for Heating Oil Inspectors to calculate efficiency levels (CO2, temperature & soot content) from exhaust gasses in the flue - read more ...


SHELL (ver. NL)Pocket Heating Oil Central Heating Efficiency

Uniquely slide is part of closed frame (no cursor) on back of stock​ - registered design commissioned by Shell Nederland Verkoopmaatschappij (SNV) for Heating Oil Inspectors to calculate efficiency levels (CO2, temperature & soot content) from exhaust gasses in the flue - read more ...


SHELL-MEX/BPPocklet Heating Oil Stack-Loss

Shell-Mex & BP logo’s on back + one open window with 1 hairline in back + follow-on from earlier Central Heating Efficiency model made for Shell in NL (SNV)​ - read more ...


THERMOCOAXMetrology Electro

Top 3 scales are constants for Chromel, Iron & Chromel/Alumel - bottom 4 scales are for Chromel/Alumel (but smaller range) & Platinum/Rhodium (3 different %‘s) - scales on front of slide are for 2 different voltages of electrical couplings ​- inch scale on back


Griffin & Co. Ltd. (Charles)
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Horse Power Computer for Steam EnginesSpeed poly-disc (3)

Unlike similar calculators Golding's patented design (GB190708196) took into account 7 variables when calculating HP of a steam engine - read more … 


Grove, W.
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(NoName)Alcohol Gauging poly-slide(2)

Post 1824 imperial based units/gauge marks + front face bottom slide can be slotted in alongside top slide (hence it only runs to 9.5) for double length i.e. Everard-like + considered by fellow collector David Riches Missing Link between square Everard design & follow-on duplex models - read more ...


Halden (Joseph)
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Calculex -1795AWatch Eugene Dieztgen - Type 2

Yellow rear cursor glass stamped with the no. 45 suggests this model was retailed by Eugene Dieztgen


DafieldMonetary

Made by John Davis & Son - Patent No. GB227643 in well


Heath & Co.
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HezzanithTwaddell Hydrometer

Refrigerant brine strength tester used on ships or in cold stores + scale runs from 35 to 50 for 60º F - see also slide rule calibrated in Twaddell’s


HezzanithEnhanced Mannheim

Inch (32nds) & cm (mm) scales in well of stock - conversion tables on back


Hezzanith CarmodyCelestial Navigation/Log-Log

Probably designed by Dr. Carbody but OEM (P1572) from Blundell Harling (box + insert & patented adjustment screws) - cm scale on back + unique table of half-versine or haversines - the table is vital when the distance between two points is < 400km


Hezzanith Le PatourelCelestial Navigation/Mannheim

Probably Thornton-made (similar to PIC 3654) - reduction scale (not Haversines) by Captain Charles Le Patourel in well of stock for correcting degrees above horizon when a star transcends its meridian - Le Patourel compiled tables of nautical data also on back


Hemmi
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1Enhanced Mannheim

Branded on front but no discernable model no. but part of obsolete 1-18 range of model no.'s abandoned circa 1930 + cm scale in well of stock + metal backing plate & paper table of conversion factors/scale on bac


1/1Enhanced Mannheim

Part of obsolete 1-18 range of model no.'s abandoned circa 1930 + metal backing plate & paper table of conversion factors/scale on back


101ADemonstration Enhanced Mannheim

Classroom version for models 40RK & 43A - Sun was added later as company logo ​


130Darmstadt

Branded in well but no discernable model no. + unusually extra S,T scales on the bottom side edge + metal backing plate & plastic table of conversion factors on back


135Pocket Darmstadt

metal backing plate


136Pocket Darmstadt

unusually extra S,T scales on the bottom side edge + metal backing plate & plastic table of conversion factors on back


149APocket Log-Log

branding on back of stock + A model no. suffix = additional catalogue/bookkeeping listing but otherwise no change to 149   


255DElectro Hyperbolic

For Electrical Engineering + D model no. suffix = with DI scale but otherwise replaced 155 + metal end braces


257LChemical

model name suffix L probably refers to the LM scale for calculating Logarithmic Mean Temperature that replaced the F(t) scale found on the original 257 + special gauge marks for determining atomic & molecular weights    


259DLog-Log

branding on back of stock + metal end braces + D model no. suffix = with DI scale but otherwise identical to 259


260Log-Log

metal end braces + WULFF & UNIVERSITY with branding stamped into both side edge


2640Enhanced Mannheim

Reissued version of model 50W for post 1940 2600 series with the K scale unusually delegated to back of slide + metal backing plate & plastic table of conversion factors on back


2664STechnical

Cobranded with Masoneilan + S model no. suffix possibly = 2664 with supplementary green coloured CIF scale + metal backing plate & plastic table of conversion factors on back


2690Stadia Topography - 360

metal backing plate & plastic table of conversion factors on back


275Desktop Hyperlog Electro (ver 1)

Desktop version of 25cm model 255 - ​§ scales on front face for converting degrees into radians & vice-versa - supposedly for Advanced Electrical Engineers.


279Desktop Expert Mechanical Engineer

metal end braces - desktop version of 259​


30Lilliput Enhanced Mannheim

Promotional model for Swedish company + metal backing plate


30Lilliput Enhanced Mannheim - late

Metal backing plate


301Control Engineering

Design invented by Prof. Keisuke Izawa of Tokyo Institute of Technology for frequency responses of physical systems where transfer functions can be linear & exponential + extremely complicated to use with multiple cursors + metal backing plate + see also advanced sibling 301A 


301AControl Engineering

Designed  by Prof. Keisuke Izawa of Tokyo Institute of Technology for frequency responses of physical systems where transfer functions can be linear & exponential + overlay co-developed with Tomoaki Morinaga especially for quadratic factor + extremely complicated to use with multiple cursors/overlay +  metal backing plate + see also “basic” sibling 301 


32Lilliput Enhanced Mannheim

Identical to model 30 but given model no. 32 because of magnifying cursor + red logo on right-hand end of slide = retailer's trademark + metal backing plate


32R (POST 1441)Lilliput Enhanced Mannheim

Model no. suffix R = with reciprocal CI scale (suffix later dropped) + co-branded on back POST 1441 + metal backing plate


34Pocket Mannheim

metal backing plate stamped with “G. DIKKES & Co N.V.”


34PPocket Mannheim

significance of the P model no suffix not known + metal backing plate stamped with “BYGGNADS AB JOHAN GUSTAFON & SONER”


34RPocket Enhanced Mannheim

branded on front but no discernable model no. + R model no. suffix = basic 34 with reciprocal CI scale + metal backing plate


34RKPocket Rietz-like

RK model no. suffix = basic 34 with reciprocal CI & K scale + metal backing plate


34TPocket Enhanced Mannheim

T model no. suffix possibly = basic 34 with Trig scales + metal backing plate stamped with “SUN”


34TPocket Enhanced Mannheim - late

T model no. suffix possibly = basic 34 with Trig scales + plain (no SUN or ASEA stamping) metal backing plate


35Lilliput Enhanced Mannheim

metal backing plate stamped BOFORS


40Enhanced Mannheim

branded on front face  but no discernable model no. + metal backing plate & plastic table of conversion factors on back


40RKRietz-like

RK model no. suffix = basic 40 with reciprocal CI & K scale + metal backing plate


50Enhanced Mannheim

same as 4x models but with an extra CI scale + metal backing plate


64/3Enhanced Mannheim

/3 model no. suffix = 3-line cursor + later siblings


64TRietz

considered extended version of the basic Rietz 64 because of additional scales + T model no. suffix possibly = basic 64 with extra Trig scales + later broader 642T sibling + metal backing plate & plastic table of conversion factors on back


70Desktop Improved Rietz

Branded in well but no discernable model no. + table of conversion factors on back - also sold as Tamaya 4480 


74Pocket Rietz

branding on back of stock + metal backing plate


80/1Electro - imperial

branded in well but no discernable model no. + W,V scales in well + /1 model no. suffix = 1-line cursor + metal backing plate


80/3Electro - metric

branded in well but no discernable model no. + W,V scales in well + /3 model no. suffix = 3-line cursor + metal backing plate & plastic table of conversion factors on back


86/3Pocket Electro

branded in well but no discernable model no. + W,V scales in well + /3 model no. suffix = 3-line cursor + metal backing plate & plastic table of conversion factors on back


BaseballPocket Sport

Probably a promotional give away for a professional baseball team but model is listed in Hemmi Catalogue 6911 + example calculations in instructions use baseball data from 1965 season


FoxboroPipe Flow & Valve Sizing - metric

Maker's branding only stamped into cursor + 3rd party dual branding with econosto n.v. + green end braces & Reynolds No. on back +  


P24Student Technical

P model no. prefix = plastic + green coloured end braces


P253 VectologLog-Log

Plastic version of 264 marketed with an "Arrow Feather Shape" for easy/smooth operation + grey end braces on back


P261Log-Log

Green end braces & cursor trim


P280Darmstadt-like two-tone
P281Rietz-like two-tone
P40RKEnhanced Mannheim

Dark-grey end braces with cursor windows


P45KTechnical

P model no. prefix = plastic & K model no. suffix = addition of K scale to basic 45 but other than being  open-frame, identical to 45K + green coloured end braces


P45STechnical

All plastic version of 45K + /S model no. suffix = simplified version of P45K


Hexadaisy Products
ModelTypeCommentsThumbnail
HEXADAISY Hexadecimal CalculatorArithmetic/Conversion for computer programmers

Slide chart for adding, subtracting & converting between decimal & hexadecimal with copyright A695383 held by Erich A. Pfeiffer + two tables – probably called & trademarked “HEXADAISY” because it looks like a member of the aster family of flowering plants


HEXCO Inc.
ModelTypeCommentsThumbnail
HEX adderHexadecimal slide adder for computer programmers

Registered design - company started by ex-IBM system engineers Tom & Linda Tarrant - catchy company slogan: “IBM 360 Programmers without 16 fingers ?” - read more ...


Hicks J.J.
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Pilot Balloon Mark IDesktop Meteorology poly-slide (2)

Meteorological Office (MO) No. 676/38 - innovatively two slides can be locked together & act as one or when unlocked, move independently BUT even when unlocked, if top slide is moved it takes bottom one with it.


Hoehler A. A. (HH)
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UniversumRietz

​HH = firm A.A. Hoehler aus Hohen Neuendorf - rare model from former GDR with uncommon scale length - table of conversion factors on back + 2 cursor windows


HONO
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300 No. 1Rietz-like

All scales on front face - FAé-LuM on back refers = Force Aérienne–Luchtmacht i.e. OEM model for Belgium Air Force (source: Ronald van Riet) - HSB on back possibly company logo


Hope Slide Rule Mfg. Co.
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51Enhanced Mannheim

Made same model for Hemmi ( P3526) but mainly retailer to Japanese OEM's like Fuij, Kutsuwa, etc​


Inglis
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FlashBank Interest poly-slide (4) calculator

Hybrid ready reckoner/tabular calculator for calculating bank interest due on deposits, discounting bills or prepayment of calls for amounts between GBP 10 to GBP 1000 - read more ...


FlashPocket Engineer's poly-slide (2) calculator

Hybrid ready reckoner/tabular calculator for machinery & other engineering related conversions & problems - read more ...


FlashSquare and Cubic poly-slide (4) calculator

Hybrid ready reckoner/tabular calculator for calculating square areas & cubic volumes - left-hand page of scales for calculating (imperial only) in feet and inches up to 20 sq. feet & 100 cubic feet - right-hand page of scales is for calculating (imperial & metric) in yards, feet or inches up to 100 sq. yards & 100.000 cubic yards - read more ...


FlashUniversal poly-slide (4) calculator

Hybrid ready reckoner/tabular calcuator for a wide variety of calculations including imperial based units - read more ...


ITAB (Internationaler Tabellenverlag)
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Kalksandstein-RechnerPocket Sand-lime House Bricks

For calculating required thermal insulation when building a house with sand-lime bricks - unique patented (DE1774408) magnetised slide - slide not reversible but scale used only in conjunction with cursor window in back


Linde-GasrechnerPocket Chemical / Gas Conversion

​Specially commissioned by German Linde A.G. gas company for calculating relationship between Litres, Kg & M3 for the chemical composition of various gasses - unique patented (DE1774408) magnetised slide - slide not reversible but scale used only in conjunction with cursor window in back


IWA (Ingenieurbuero fuer wirtschaftliches Arbeiten)
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14127 HaffmansBeer Brewing

Specially commissioned by Dutch quality control equipment supplier Haffmans for brewing & related industries + © design for calculating CO2 % in beer by weight using formula devised by Dutchman J. van Strien when working for Dutch brewer Heineken + later sibling 14162 version for calculating CO2 by volume - part of pharmaceutical, chemical, physical & medical purposes series


14162 HaffmansBeer Brewing

Specially commissioned by Dutch quality control equipment supplier Haffmans for brewing & related industries + © design for calculating CO2 in beer by volume using formula devised by Dutchman J. van Strien when working for Dutch brewer Heineken + earlier sibling 14127 version for calculating CO2 by weight - part of pharmaceutical, chemical, physical & medical purposes series


14350 ECGCardiology

Ruler to help cardiologists analyse printed electrocardiographs (ECG’s) traces from electrocardiogram machines for standard paper speeds of 25 or 50 mm/s - part of pharmaceutical, chemical, physical & medical purposes series


15379 (TF 65/2)Music Piano & Harpsichord Builders

Specially commissioned (2500 made) & exclusively sold by German music retailer Verlag Erwin Bochinsky ​(trading name Verlag Das Musikinstrument) + based on earlier prototype by German master piano builder Klaus Fenner for wound & unwound strings + calibrated for imperial & metric sizes + table on back for recalibrating steel core wound strings - part of sundry applications series


15512 CocktailwählerLilliput Mixology

Slide chart in © credit card format for mixing 22 different cocktails + with half no. of cocktails but uncannily similar to BH version - part of sundry applications series


J. A. Nicholl & Co.
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Mark VI Desktop Artillery for Indirect Fire

Serial no. = 48 - called Apparatus for the Observation of Fire was intended for use by lance-corporals & corporals in the field & not on a desk - issued by Min. of Defence


J.H. Steward Ltd.
ModelTypeCommentsThumbnail
(NoName) Pocket Joint Round-hinged English Sector

Used with a set of dividers - OEM made (possibly by Jacob & Halse/Abraham group) but pre 1913 when Steward became a Ltd. - read more ...


(NoName)Pocket Rectangular Protractor/Diagonal Scale - imperial

0-360 degree model OEM made but pre 1913 when Steward became a Ltd. - read more ...


B1243 McleodLilliput Military Artillery Gunnery

Mini gunnery rule for Field Artillery Officers designed by Lieutenant-Colonel N.M. McLeod with folded scales - slide not reversible but one open window in back


J184Enhanced Mannheim

​OEM by D&P (model I) - cm scale & DRP 126499 in well + 2 cursor windows in back & 3 adjusting screws in bottom side edge - A.G.N. WYATT. on front face suggests a special commission for Rear-Admiral Arthur Guy Norris Wyatt who joined the RN Surveying Service in 1918


Motor TransportPocket Military Vehicle Logistics & Supply

OEM made but post 1913 when Steward became a Ltd. - earlier version known as Vee Tee Meter - VEH = no. of vehicles - V.T.M. = Vehicles To the Mile - M.I.H. = Miles In an Hour or mph - read more ...


Jackson Brothers Ltd.
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(NoName)Mannheim

Little known maker from Leeds, UK


Jakar
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22Pocket Darmstadt-like two-tone

OEM by FUJI


33Pocket Log-Log two-tone

OEM by FUJI


532APocket Rietz two-tone

OEM by FUJ


99Log-Log two-tone

OEM by FUJ but without rubber feet


Johann Faber
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9205 (SYSTEM RIETZ)Rietz

OEM version made by KHH (5 slits in well + 5 adjustment screws on bottom side edge) + conversion tables & 2 cursor windows in back


9206 (ELECTRO 15) Electro

OEM version made by KHH (5 slits in well + 5 adjustment screws on bottom side edge) but often mistaken as D&P because of model no. - V & W scales in well of stock + conversion tables (in NL) & 2 cursor windows in back - see also identical model sold by Ahrend, OHICO & Kahn Frères


John Davis & Son (Derby) Ltd
ModelTypeCommentsThumbnail
(NoName)Student Mannheim

Made by Dennert & Pape: no steel back, 4 horizontal slits in well of stock, veneers fixed by 6 screws, early D&P pi gauge mark - double bevelled edge model + paper scale for conversion factors on back


AutocratMannheim with Trig scales

“British Made” - steel back + paper table of conversion factors


CelluloidMannheim with Trig scales

Made by Dennert & Pape: no steel back, early D&P pi gauge mark + extension of inch scale (10-20) in well of stock + 06 & D.R.P. No 126439 stamped in well of stock


CelluloidMannheim with Trig scales - early

Made by Dennert & Pape: no steel back, 4 horizontal slits in well of stock, no pi gauge mark - railway track scales + extension of inch scale (10-20) in well of stock + John Davis cardboard enclosure for conversion factors, etc


DemocratDesktop Mannheim with Trig scales

15” version of Autocrat model with extension of cm scale (16-32) in well of stock. “British Made” - steel back + paper table of conversion factors


DubilierCapacitance Electronic poly-slide (2)

Made by A.G. Thornton: design copyrighted by Philip Ray Coursey whilst working for Dubilier Condenser Company - JOHN DAVIS & SON Ltd printed on the back and MADE IN ENGLAND in well of stock


DurocratDesktop Mannhiem

Unmarked - cm scale extension + 6 slits in well of stock - L scale reversed


GliderRietz

Glider name comes from slide-long slotted metal patented (GB232037 - L.E. Edwards) tensioning spring for “automatic” smooth sliding - steel back + paper table of conversion factors


John Rabone & Sons
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(1206) PerforsPocket Calliper Rope / Bulb Gauge

No model number but appears to be specially commissioned modern version of 1206 for Dutch bulb grower J.H. Perfors for measuring bulb diameter & giving circumference alongside as bulbs commercially sold & graded by size


(1460)Pocket Calliper Conversion Gauge

No model number but appears to be modern slimmed-down version of 1460 for converting between imperial & metric


(NoName)Glovers Rule

Squared tapering rule with identical inch scale on each side for measuring length of a glove


1165Joint 4-fold Large Square-hinged Protractor Rule

Colloquially known as a “Blind Man's” rule because of the size & thickness of the numbering made it easy to see with poor eyesight or in low light 


1206Pocket Calliper Rope Gauge

For measuring rope diameter & giving circumference alongside + rope (metal & fibre) weight tables on front & back as rope commercially sold by weight not length


1206 Oude LijnbaanPocket Calliper Rope Gauge

Specially commissioned version for Dutch ropeworks De Oude Lijnbaan Ltd. for measuring rope diameter & giving circumference alongside + rope (manila & sisal) weight table on back as rope commercially sold by weight not length


1211Pocket Joint 4-fold Old Arched-hinged Calliper Rule

Calliper scale in 32nd’s of inch


1550Beer Dipping

Unmarked square rod but with Rabone "look & feel"


Carpenter Timber No. 2379 Pocket Joint 4-fold Old Arched-hinged Coggeshall

D Girt line = 4-40 + two-entry ½ to ¼ scale table & 12-18 “Pence per Load” table (split over 2 legs) on front


Carpenter Timber No. 2423Joint 2-fold Vulcan-hinged Coggeshall

D Girt line = 4-40 with Vulcan logo & design lozenge for 1869 + two-entry ¼ to ½ scale table on front + ¾-length E & M scales (split over 2 legs) on back


Jorgensen (Ole)
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7888 International Circle Pencil Cup/Desk Tidy Time Converter

Red with two black & one red rotating ring - made in Hong Kong


BulkoilPencil Cup/Desk Tidy Metric Converter

Black with two rotating rings - made in Denmark


CCWPencil Cup/Desk Tidy Basic

CCW = original Creative Workshop Inc. version - black with four grey metal rotating rings - made in Denmark


Control Data Universal CirclePencil Cup/Desk Tidy Basic

Black with two white & two grey rotating rings - made in Denmark


Kahn Frères
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Electro 15Electro

OEM version made for Brussels-based retailer by KHH (5 slits in well + 5 adjustment screws on botton side edge) but often mistaken as Dennert & Pape because of model no. - V & W scales in well of stock + conversion tables on back - see also identical model sold by Ahrend & OHICO


Kembo-Cuisenaire
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MasterKeyMusic Transposer poly-slide (2)

Thick plastic construction with copyrighted design by Australian A.B. Packer + later version was duplex blue & white


Kemigravyr AB
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M 3134-701 Photographic

Made for Swedish Air Force​ (coat of arms top left) for aerial photography


KENT
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(NoName)Pocket Rietz two-tone

OEM by Uchida


7153Rietz-like two-tone

OEM by Uchida + unusual & more convenient for a Rietz all scales on front face - cm & 1/20 inch on back  


7153LL Darmstadt two-tone

OEM by Uchida - cm & 1/20 inch on back


Keuffel & Esser (K&E)
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4012 (type 2) Thacher's Calculating Instrument Desktop Basic long-scale

​Special anniversary gift from Ros - serial no. = 1685


4051Desktop Enhanced Mannheim

Serial no. 322 + 5 adjustment screws & conversion table on back


4080-5Desktop Decitrig Log-Log

Serial no. 445698


4081-5Desktop Decitrig Log-Log

Serial no. 902506


N-4053-5 Desktop Polyphase Enhanced Mannheim

N prefix for new version + serial no. 740727 + 5 adjustment screws & conversion table on back


N-4088-5Desktop Polyphase Technical

N prefix = new/modified version + serial no.: 235840​


N-4096Desktop Merchants' Business

N prefix for new version + serial no. 699855 + stripped back scale layout for just x, ÷ & proportions + 5 adjustment screws & conversion table on back​ + with the lid open can be used in box!


N-4101 Desktop Stadia Topography - 360g

N prefix for new version + serial no. 106473 + 5 adjustment screws & conversion table on back


Short Base TriangulationDesktop Military Artillery Range Finding

Specially produced chunky model with a Mannheim-like layout based on Mils - read more ...


Kienzle
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MultiplikatorWristwatch Calculator Basic

A gift from Ros - manual winding with date function​


Kingson
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Four-Rule CalculatorPocket Mannheim Addiator

Traditional 6 slides x 6 digit display slide adder on front/top with Table of Decimal Equivalents & slide rule on back but otherwise blatant Hong Kong copy of German-made ARITHMA + impractically inch & cm scales (top & bottom edges) are on front of slide but remain for the most part hidden from view    


Pocket CalculatorPocket Slide Adder

For adding/subtracting - table of decimal equivalents under subtraction section but otherwise blatant Hong Kong copy of ARITHMA


Klawun, Joe
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1001 T (F-C 67/22)Pocket Business - System Klawun

OEM version made by Faber-Castell for pre-decimal British £sd


1001 Ü (F-C 44/22)Desktop Business

OEM version made by Faber-Castell - British pre-decimal + 6 slide tension adjustment screws in bottom side edge + pictorial instructions & tables of constants on back


16 C (F-C 67/91)Pocket Enhanced Mannheim

OEM version made by Faber-Castell


KLPV - Factory for Calculating Instruments - Kiev
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(NoName)Rietz

ROCT (GOST) Russian State Standard No. = 5161-57 + two open windows with cursor line in back


Koch, Huxhold & Hannemann (KHH)
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(NoName)Electro

5 slits + name & Hamburg & V & W scales in well of stock + typical 5 slide tension adjustment screws in bottom side edge + table of conversion factors & 2 cursor windows in back


1050Desktop Rietz

On balance probably KHH-made (some but not all of typical KHH traits) but mysteriously “Sistema Rietz” (Spanish) in gold lettering on slipcase & stamped in well of stock - paper data slip missing from back​


System KorteArithmetic

German Registered Design (DRGM 699 054) from 1919 by Friedrich Korte for all 4 primary mathematical operators​ (x ÷ + - ) when calculating with large (long) numbers - inch scale upside down on bottom side edge


System MannheimEnhanced Mannheim

5 slits + name & Hamburg in well + typical 5 slide tension adjustment screws in bottom side edge + table of conversion factors & 2 cursor windows in back


Walter PfefferPipe Flow in sewerage pipes

​Special commission for German engineering company: Walter Pfeffer Nachf, Halle - two filling height tables for circle & oval profile pipes on back


KUTSUWA
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FN-401Pocket Enhanced Mannheim without Trig scales
FN-801Enhanced Mannheim

Billed as Pocket Basic Mannheim model but is too long for any pocket & has Trig scales 


L&C Hardtmuth / Classic
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Series IMannheim

Unusually for any maker top edge is flat & bottom edge is bevelled - bottom bevelled cm edge scale upside down + table of constants on back


Series IPocket MannheimTop bevelled edge inch scale upside down + table of constants on back
Series IILog-LogBottom edge cm scale upside down + table of constants on back
Series IIPocket Log-Log

Bottom edge cm scale upside down + table of constants on back


Series IIIPocket MannheimBottom bevelled edge cm scale upside down + unit of measure extension (inch) scale in well of stock + table of timber constants on back
Series IVMannheim + TrigStrange/unusual scale layout - bottom bevelled edge cm scale upside down + table of constants on back
Series VLog-Log extra

Series model no. strangely left off - unusual choice of scales - bottom bevelled edge cm scale upside down + table of constants on back


Series VIRetail & Monetary

Based on patent GB621133 (A.W. Parkes) for pre-decimal pounds sterling + bottom bevelled edge cm scale upside down


Lawrence Engineering Services
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10-B blueEnhanced Mannheim without Trig scales

Monchrome blue version of standard 10-B with conversion tables on back


10-B DeLuxeEnhanced Mannheim without Trig scalesDeLuxe = magnifying cursor. Conversion tables on back of rule
10-B DeLuxe (ver. Grosset & Dunlap)Book + Enhanced Mannheim without Trig scales

How To Use It (instructions & tests) dirty orange & black book by Sommers/Drell/Wallschlaeger & published by Grosset & Dunlap 


10-B DeLuxe (ver. Wilcox & Follett)Book + Enhanced Mannheim without Trig scales

How To Use It (instructions & tests) dark-green & gold book by Sommers/Drell/Wallschlaeger & published by Wilcox and Follett Co. with extra loose-leaf Answers addendum + slide rule in back


10-B OEMGENE LOEWY Enhanced Mannheim without Trig scalesname on enevelope not rule
10-B OEMLARCH Enhanced Mannheim without Trig scalesname on enevlope not rule
10-B originalEnhanced Mannheim without Trig scales

Early & famous 25¢ slide rule - read more ….


10-B standardEnhanced Mannheim without Trig scales

Conversion tables on back


10-CEngraver's and Photographer's Proportion Calculator

For area % up & down scaling


10-DLumber Calculator - basic version

For lumber volume in board feet


10-D0Lumber Calculator

For lumber volume in board feet


10-FPricing and Inventory Rule

For discount or profit margin mark-up per gross/dozen/each in $‘s


10-GCutting Speed Calculator

For recommended machining cutting speed in f.p.m for given drill speed & size


10-IModel Builder's Slide Rule

For calculating the scaled down dimensions (various railway gauge sizes) for replica scaled models of railroads/trains


10-NPrinter's Proportion Rule

For moving between inches & picas when printing/publishing


12-HCopyfitter printing

For font size and letter/word/line spacing in points and picas - layout © Owen T. Taylor


12-JPro-Rater

For calculating days between two dates & pro-rata premium/days


250-BTEnhanced Mannheim

Conversion tables on back


250-BT OEMCHARVOZ-ROOS SR31 Enhanced Mannheim

Conversion tables on back


250-BT OEMDU PONT Enhanced MannheimConversion tables on back
250-BT OEMLIETZ 2974N Enhanced Mannheim

Conversion tables on back


250-BT OEMUS NAVY Enhanced Mannheim

Conversion & gauge marks tables on back


250-VEnhanced Mannheim

Marketed as a “Professional Slide Rule” - conversion tables on back


6-OpPocket Photographic Calculator - early

For Photoflash Lamps but missing top colour film scale found on the later Flashrule version  - photography tips printed on back​


6-OpPocket Photographic Flashrule

For GE or Westinghouse Photoflash Lamps - photography tips printed on back


6-OwPocket Photographic Flashrule

For WABASH Photoflash Lamps - photography tips printed on back


8-AMannheim

Conversion table printed on back - Wabash made


8-BEnhanced Mannheim without Trig scales

Conversion table printed on back - Wabash made


8-B OEMANCO Enhanced Mannheim without Trig scales

Paper table of decimal equivalents on back


8-B OEMDU MONT Enhanced Mannheim without Trig scales
8-LCopper Wire Selector

For minimum wire size/volt (440/220/110) in A.W.G. - conversion tables on back


8-LCopper Wire Selector - basic Cedar Valley versionFor minimum wire size/volt (440/220/110) in A.W.G
9-KMusic Transposer

For constructing chords in any key & transposing one key to any other


B.F. GrizzleGas Displacement Meter Calculator

Specially commissioned by B.F. Grizzle for calculating gas rates through displacement meters @ various pressures - layout © B.F. Grizzle


B.F. GrizzleGas Low Pressure Line Flow Capacity Slide Rule

Specially commissioned by B.F. Grizzle for calculating open flow rates using pilot tube pressure readings - layout © B.F. Grizzle based on Spitzglass’ formula


B.F. GrizzlePipe Flow foe water

Specially commissioned by B.F. Grizzle for calculating the friction loss in a section of water pipe & head loss for a given pipe diameter, length & flow - layout © B.F. Grizzle based on Hazen–Williams equation


B.F. GrizzlePipe Flow for gas

Specially commissioned by B.F. Grizzle for calculating the gas flow capacity/hour through a pipe of a given diameter - layout © B.F. Grizzle based on Panhandle Eastern Pipe Line formula
 


B.F. GrizzlePipe Open Flow Capacity

Specially commissioned by B.F. Grizzle for calculating open flow rates based on pilot tube pressure readings & using Reid’s formula for pipe profiles - layout © B.F. Grizzle


B.F. GrizzlePipe Orifice Meter Calculating Rule

Specially commissioned by B.F. Grizzle for calculating the size of conduit restriction needed to create a required pressure drop - layout © B.F. Grizzle


Canadian Radium & UraniumGamma-Ray Radiographic

Specially commissioned by Canadian Radium & Uranium Corp. for commercial (steel or alloys) rather than medical use - for determining the appropriate exposure times for radiographic images involving radium-226 sources


CaprockConcrete Quantity Calculator

Specially commissioned by Caprock Materials Co. for calculating cubic yards of concrete needed for or in a wall of certain dimensions


Code-MakerPocket (boxed pair)

Rules carry an advertisement for Robin Company, Chicago


Code-MakerPocket Beich

Part of loyalty scheme for sales of WHIZ chocolate bars


Code-MakerPocket Dick Tracy

Because of the Dick Tracy connection presumably marketed in cooperation with the “Chicago Tribune New York News Syndicate”


Fun IncorporatedPocket Poker Meter Gambling

Specially commissioned by Fun Incorporated + © design from 1950 by Ideas Unlimited read more …


L.E. WaddingtonMusic & Music Acoustics

Specially commissioned by L.E. Waddington for adjusting relative vibration rates, degrees of scale, intervals, chord structures, scale indications & transposition data against a piano keyboard - based on several standard frequency level specifications - layout © L.E. Waddington - Reference Frequency table in well - Subscript Notation, Instrument tables, Time Signatures & nomograms on back


MadisonCutting Speed Calculator

Specially commissioned by Madison Manufacturing Company for calculating the drill and cutting speed for machining a given diameter - extra tables on back


Miller MotorAir and Hydraulic Cylinder Calculator

Specially commissioned by Miller Motor Company for calculating air & hydraulic cylinder values such such as thrusts, bores, areas displacements, etc - conversion tables on back


MIT AntennaRadar antenna performance

Specially commissioned by Massachusetts Institute of Technology (MIT) for calculating an antenna’s beam width as a function of the diameter of the antenna & wavelength being used + scales for converting imperial to metric & radians to degrees - design based on research by Roy C. Spencer (RSC) for calculating radar antenna beam patterns, beam width, gain, etc. Its use, for a slide rule, was uniquely classified by both UK & US governments during WWII. 


Murphy & MurphyConcrete Quantity Calculator

Specially commissioned by Murphy & Murphy Inc. for calculating cubic yards of concrete needed for or in a wall of certain dimensions


PioneerEpperson TV coverage calculator

Specially commissioned by Pioneer to calculate approximate 'Grade A,' 'Grade B' & 'Principal City' Coverage for all VHF and UHF Television Stations from TV station's published power & antenna height + gives approximate field strength in microvolts/meter for distances up to 100 miles from transmitter + UV/M-DB conversion scale on back - layout © J.B. Epperson


Plaza ExpressTraffic Manager's

Specially commissioned by Plaza Express Company Inc. for checking freight shipping charges or shipping rates or shipping truck/carload breaking points & calculating storage costs - layout © M.T. Brockman


RCAF.M. coverage calculator

Specially commissioned by Radio Corporation of America for estimating coverage of FM radio stations according to the type of RCA antennae


Statham LaboratoriesPoker Meter Gambling

Specially commissioned by Statham Laboratories + © design from 1950 by Ideas Unlimited read more …


Taylor PublishingCopyfitter printing

Specially commissioned by Taylor Publishing Co. with scale layout © Owen T. Taylor & identical to 12-H + CCP paper table gives Characters Per Pica for extensive list of different type faces & fonts for both upper & lower case - 


TenbrookL.P. Gas

Specially commissioned by Tenbrook Enterprises for calculating the temperature correction (°F) needed when making bulk deliveries of Propane


ThomasMusic Composition & Transposer

Specially commissioned by Thomas Specialities for composing, transposing or creating harmonies - layout © Thomas


Tokheim 92K Factor Heating Oil Supply

Specialty commissioned by Tokheim Oil Tank & Pump Corp. for calculating supply requirements of household heating/fuel oil - K factor is a way of showing (gallons/degree day) how fast a consumer uses fuel (analogy = miles/gallon in a car)


US Army (DeYOE)Military Artillery Range Finding

Specially commissioned by US ARMY + called a “Graphic Table” by the US military & used for “Bracketing” i.e. flooding an area with shells rather than precise aiming - “Y” probably refers to Howitzer gun & “OE” = observed errors + Mils range suggests mortar shelling


US Aviation UnderwritersInsurance

Specially commissioned by United States Aviation Underwriters Inc. for actuarial-based calculations + table on back for cancellation ratio’s/days - layout © Albert J. Smith


Le Girondin - ELPE
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TOTALISSlide Adder

Marketed for pre-Euro (2000) calculating in French Francs (Fr) & Centimes ​


Leningrad Factory
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(NoName)Desktop Military Artillery Range Finding

Made in the style of earlier Russian Prometei-made military/pilot slide rules. Intriguingly the military RWTL-2 labelling (in German) on the box stands for Rockets and Weapons Storage - 2 @ Hennersdorfer Heide, Lower Austria. ​


LFAI - Leningrad
ModelTypeCommentsThumbnail
(NoName)Desktop Rietz

ROCT (GOST) Russian State Standard No. = 5161-57 + conversion factors & formulas on back​


(NoName)Pocket Rietz

ROCT (GOST) Russian State Standard No. = 5161-57 + two open windows with cursor line in back


(NoName)Rietz

ROCT (GOST) Russian State Standard No. = 5161-49 + conversion factors & formulas on back


Lines Bros Ltd / Tri-ang
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C276 Scalextric Speed ComputerTime-Speed-Distance calculator

Scalextrix model car racing sets (now distributed by Hornby) date from 1950s - calculator gives scaled (32:1) equivalent MPH or KPH for distances travelled for clocked no. of seconds - track slot lengths/type in cm for finding total track length on back


LINEX
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(NoName)Enhanced Mannheim

Two spring-loaded ball bearings in top side of well to tension slide. Read more ...


1253Pocket Mannheim

Unbranded


LOFTUS, William R.
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(NoName)Alcohol Gauging, Ullaging & Reducing poly-slide(2) spile rod set

​6 round spile rods screw together to make 5 foot dipping rod with inch & imperial gallon scales + front face for Gauging & Ullaging calculations & reverse side for Reducing & Stocktaking calculations


Sikes' 61871-rule Alcohol Hydrometer set

Layout on back of Proof rule merely extends range from front + hydrometer scale runs from 0-10 range + full set of 9 brass weights (10 - 90) all stamped: 6187 + thermometer by J. Casartelli & Son


LOGA Calculator A.G.
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15m (ver. E)Desktop Basic long-scale

Serial No. 155202 (“15” correlates to scale length & “5202” = no.) + version “E” = Einfach/elementary


2.4m (ver. E)Desktop Basic long-scale - yellow

Serial No. 2237 (possibly correlates to overall scale length) + version “E” = Einfach/elementary


30E (ver. 2)Basic

Model suffix “E” = Einfach/elementary - budget 3-spoke metal backplate - see also bigger sibling


30RC (ver. 2)Business

Serial No. 65 + model suffix “R” = with reciprocal scale & “C” = commercial + turning lever - try out here the online simulation created by Andries de Man


30RZhRetail/Conversion

Serial No. 0289 + model suffix “R” = with reciprocal scale, “Z” = extra Zins/interest scale & “h” = with turning lever - see also bigger sibling


30sR (ver. 2)Basic+

​Model suffix “s” = lightweight construction & “R” = with reciprocal scale + back anodised brass colour & serrated/knurled edge to disc


30sT (ver. 1)Technical

Model suffix “s” = lightweight construction & “T” = Technisch/technical scales + budget 3-spoke metal backplate - see also bigger sibling


30Tt/360º Technical

Serial No. 64207 + model suffix “T” = technical scales & “t” = with trig scales + black turning lever - try out here the online simulation created by Andries de Man


30Tt/360ºTechnical - early

Serial No. 1659 + model suffix “T” = technical scales & “t” = with trig scales + grey turning lever - try out here the online simulation created by Andries de Man


7.5m (ver. E)Desktop Basic long-scale - white

Serial No. 751030 (“75” correlates to scale length & “1030” = no.) + version “E” = Einfach/elementary


75 Praezision 6400 A 0/00Desktop Military Artillery/Stadia Topography

Serial No. 82 with sin, cos & tan scales calibrated in 6400 NATO Mils favoured by the military + sin & cos scales are divided into 4 subscales + see also smaller siblings


75EDesktop Basic long-scale

Model suffix “E” = Einfach/elementary - see also smaller sibling - try out here the online simulation created by Andries de Man


75EADesktop Basic/Monetary/Conversion long-scale

Serial No. 3474 + model suffix “E” = Einfach/elementary & “A” = additional scales for GBP & imperial/metric conversions - try out here the online simulation created by Andries de Man


75RZ (ver. 2)Desktop Retail/Conversion long-scale

Serial No. 4100 + model suffix “R” = with reciprocal scale & “Z” = extra Zins/interest scale - see also smaller sibling


75TDesktop Technical long-scale

Model suffix “T” = Technisch/technical scales + more accurate later addition to product range marketed to both schools & commerce - see smaller sibling - try out here the online simulation created by Andries de Man


K150dPocket Technical/Business Rietz-like

Model prefix “K” = Kaufmann/merchant & suffix “d” = Duits/German version + unusually separate slide for each side of closed frame i.e. front (yellow slide) for business use & back (green slide) for technical use + many currency gauge points on front face/cursor + adjoined CI/% = ½ length scales + table of gauge points abbreviations in front well + table of constants in well on back ​- see also bigger sibling


K300dTechnical/Business

Model prefix “K” = Kaufmann/merchant & suffix “d” = Duits/German version + unusually specific slide for each side of closed frame i.e. front (yellow slide) for business use & back (green slide) for technical use + many currency gauge points on front face/cursor + adjoined CI/%/§ on front = mini scales + table of gauge points abbreviations in front well + % scale on back = 2-part - see smaller pocket sibling


Topo 6400 A 0/00 (ver. 2)Military Artillery/Stadia Topography - early

Serial No. 195 exclusively made for Swiss Army for artillery based azimuth calculations - two inner scales on front calibrated for 6400 A ‰ or NATO Mils (A ‰ = 2 x 3200) + see also larger sibling


Topo 6400 A 0/00 (ver. 3)Military Artillery/Stadia Topography

Serial No. 1119 exclusively made for Swiss Army for artillery based azimuth calculations - two inner scales on front calibrated for 6400 A ‰ or NATO Mils (A ‰ = 2 x 3200) + see also larger sibling - try out here the online simulation created by Andries de Man


Wetter (30E)Basic

Specially commissioned 30E for advertising by Zurich-based Wetter - budget 3-spoke metal backplate


LOGAREX
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27204-IIPocket Rietz

cm & inch scales, table of constants & two windows in back


27205Pocket Log-Log

Toison D’Or award logo on front face


27403-IIDarmstadt - early

Thick milky white plastic + two windows with hairline in back


27403-IIIDarmstadt-like

Inch scale, table of constants & two windows with hairline in back


27602-IILog-Log

Toison D’Or award logo on front face


27606 SKRIVAB TRIGSchool/Technical
27607-ITechnical
4542-27501Desktop Rietz-like

​Interesting & useable layout of scales


Logomat Rechengeräte
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EckardtConversion

​Slide chart specially commissioned Eckardt Mess- und Regeltechnik - pressure conversion on front & temperature conversion on back 


1300/1301Pocket Basic long-scale

​Stands out from Basic models from other makers because of quality & long-scale spiral D scale


1300/1302Pocket Basic long-scale

​Stands out from Basic models from other makers because of quality & long-scale spiral D & K scales


2001 PfiffiKUSWaistcoat Basic long-scale - early

​PffifiKUS = smart aid (later version duplex) - innovative but impractical single scale design & a pain to calculate with


2300Universal long-scale

Superb & unusual design + magnifying bar held in position magnetically + 6 interchangeable discs/scale layouts


3301Pocket Retail

Increased accuracy because of extra-long D scale​


4605 TankboyPocket Conversion

Slide chart for fuel(tank) consumption


5105 pr‰millerPocket Alcohol

For calculating legally allowable units of alcohol/type of drink for given body mass ​


De BeersRetail

​Slide chart specially commissioned by De Beers Industrial Diamond Division


Kalorien ZaehlerMedical

Calorie Counter​ based on patented (DE2160413) design by Heinrich Kundisch + table of calorific values of many foods


Long, Joseph
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(NoName)Alcohol Proof

Layout on back merely extends range from front


(NoName)Alcohol Proof - narrow

Layout on back merely extends range from front + narrow as a pocket model but longer


Lumley, L. & Co.
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(NoName)Pocket Alcohol Proof

Layout on back merely extends range from front


M & M Enterprises
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Circle-O-KeysPocket Music Composition

Slide chart patented (US2079920) design by Thomas J. Ozanda for musical signatures of various major & major keys


MARC A.A.F. / MINERVA
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Minerva No. 5 ElectricienPocket ElectroV & W scales in well of stock - from short lived MARC-Minerva collaboration before Minerva started importing ARISTO slide rules
No. 2 MannheimPocket MannheimInch scale & André et Yernaux, Courcelles on back
No. 2 MannheimPocket Mannheim - earlyEarly cursor & overall 5cm shorter than later versions - Cement-Ijzerfabriek “Wittenburg”, Amsterdam stamped in well - inch scale on back
No. 4 Sinus et TangentePocket Enhanced Mannheim
No. 5 ElectricienPocket ElectroV & W scales in well of stock - later plastic rather than celluloid stock
No. 6 RietzPocket Rietz
Master
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BusinessSlide Adder

Maker is Liege, Belgium based (no connection to US based Master Electric maker) - “man in cap” 1 of 3 company logo’s - addition only


Maurice Damien
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SP 10 Universal Rietz (Type 4)

Unusually all-metal for a European maker - table of conversion factors in German on back + company logo = dam - one only 3 known linear models


Mear & Co., M.H.
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Domestic Heating Calculator - model 4 imperialHeating installation design for traditional houses & bungalows - early

St. Helen’s Gate address - determines the heating requirements for older norms/types of domestic premises & also the sizes of all the equipment needed for ‘the installation”


Domestic Heating Calculator - model 9 metric Heating installation design for houses & bungalowsDetermines the heating requirements for older norms/types of domestic premises & also the sizes of all the equipment needed for ‘the installation”
Electrical Lighting CalculatorLighting/illumination

Should be used in conjunction with the Glare Index Calculator to calculates light requirements for commercial & industrial premises in lumens - table of coefficients of light fittings on back​.


Gas Flow Calculator - model 3High or low pressure gas flow in steel pipesSingle-sided - Model 3 = improved model based on Colebrook-White formula (replaced Lacey’s coefficients for such calculations)
Glare Index Calculator - metricLighting/illumination glare

Used in conjunction with Electrical Lighting Calculator to calculate a glare index according to the British Lighting Council method.​


Gommer Comprehensive Conversion CalculatorConversionSpecial commission for J. Gommer, Voorburg, NL - 2nd disc with multiple look-up windows on front - cursor on back
Orifice & Nozzle Flow Calculator - metricPipe Flow (liquids/gases/steam)

For calculating flow in pipes for various types of orifice plates & nozzles according to British Standard 1042 (pipe bores 40-2,000mm & orifice diameter 7-1,200mm) - front for results in volume or mass - back for flow coefficients


Pipe Flow CalculatorPipe Flow (liquid & gas - turbulent flow)

Special commission by JISKOOT Automation n.v., Breda, NL + for determining pipe size, flow or pressure loss for any liquid, e.g. water, fuel oils, acids, solvents & any gas (at low pressures) flowing under turbulent conditions in steel or cast iron pipes


Smith Conversion CalculatorConversionSpecial commission for A O Smith corp. London - 2nd disc with multiple look-up windows on front
SRA Helical Coil Spring Calculator - metricDesigning tension or compression in helical springsSpecial commission for Spring Research Association (SRA) - for designing helical soil springs according to BS 1726 part 1 - will handle springs made from round, square or rectangular section wire
Warm Air Heating Calculator - model 2 imperialWarm air domestic & small installations Divided into sections each dealing with a particular aspect of the overall calculation
Water Flow Calculator - model 3 imperialPipe Flow

Front for determining flow of water through pipes & ducts with circular cross-section according to Moody’s coefficients - back for determining flow of water in large open channels of any cross-section (Manning formula)


Mears, Neal F.
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MarvelMusic Transposer

Slide chart copyrighted design by Neal F. Mears & promoted as: The Slide-Rule of Music


Meierhofer (Hans)
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11054 Swiss NavigatorAviation - System Borner

“Book” construction with multiple ring-bound nested discs - patent no. (CH341321) by Armin Borner


MEISSNER KG
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(NoName)Rietz

Later versions followed - table of conversion factors on back


Rietz-Arcus 1731543Rietz-likeMissing usual K & A/B scales of a Rietz layout + unusually for a Rietz all scales on front face - “1” in equilateral triangle = East German (DDR) post 1950 certification mark for “1st or good quality”
TRIMTechnical

Unusual choice of scales & layout -“1” in equilateral triangle = East German (DDR) post 1950 certification mark for “1st or good quality” + heated stamped “93” on back


Morin, Henri
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Regle pour Essais des Duretes des Metalix Set for testing metal hardnessTable of conversion factors on back + 12 varying steel weights + set of test slides (wrapped) + rubber + heavy sprung testing piston/hammer 
MuseLab Inc.
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BluesessionMusic Teaching Guitar Playing

Slide chart patented (US5386757) design by Daniel Derrick displaying fingering patterns for 6-string rock & blues guitar


Music Rule Co.
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Music RuleMusic Piano Sharps & Flats

​Slide chart for finding sharps & flats for a given key on piano keyboard


Musigraph Company
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100Music Composing & Arranging

Designed by two professional musicians for professional composers/arrangers + supposedly only 5000 ever made


Muziekuitgeverij van Teeseling
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VT180 Guitar-DiskMusic Guitar Composition

Slide chart copyrighted by Dutch publishers for finding guitar keys (front) & guitar chords (back)


National Rechenwalze, A.G.
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10Desktop Basic long-scale

serial no. = 3545 with knurled metal turning knob - stand allows drum to be locked vertically to save desktop space


Nestler
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(NoName)Desktop Military

​Both non-standard scales folded & apart from NESTLER name in well no other markings


(NoName)Enhanced Mannheim

Railway track scales + German silver screws + cm scale in well of stock + patent no. 173660 + table of conversion factors on back


(NoName)Enhanced Mannheim - early

Railway track scales + German silver screws + cm scale & 4 slits in well of stock + patent no. 164885 + table of conversion factors on back


(NoName)Enhanced Mannheim - export Pickworth

German silver screws + inch scale in well of stock + table of conversion factors compiled by C.N. Pickworth on back


(NoName)Mannheim

Unusually unmarked (pi mark = Nestler) & incised scales + table of conversion factors in English on back​


0121Pocket Darmstadt two-tone

2 cursor windows in back


0123Pocket Rietz 360

aku CMC printed on back + 2 cursor windows


0123 (Reitz S)Pocket Rietz 360 two-tone

2 cursor windows in back​


0127Pocket International Conversion two-tone

primarily for imperial/metric conversions with many gauge marks on front face + WEATHERFORD printed on back + 2 cursor windows


0129 PolymathPocket Log-Log

OEM by FUJI but retailed through Hope Slide Rule Mfg. Co. - has big-brother 0291 sibling


0137Pocket Electro two-tone

Unusually W & V scales on front face + 2 cursor windows in back ​


0203 AlphaDemonstration Rietz two-tone

Instruction rule for model 0251 - Rietz layout but all scales on front face ​


0210Darmstadt

Table of conversion factors & two cursor windows in back


0215Desktop Darmstadt 360°

tables of conversion factors on back


0218Darmstadt

Table of conversion factors on back + 2 cursor windows


0232Rietz

​Late wooden model - table of conversion factors on back + 2 cursor windows


0235Desktop Rietz

tables of conversion factors on back


0238Rietz two-tone

Table of conversion factors & 2 cursor windows in back


0239School Rietz two-tone

Cheaper construction​ & possible OEM by Japanese Fuji + 2 cursor windows in back


0249 ElemathSchool Log-Log two-tone

OEM by Japanese Fuji  but retailed through Hope Slide Rule Mfg. Co. ​


0251 AlphaSchool Rietz two-tone

Cheaper construction​ & possible OEM by Japanese Fuji  + “Half-duplex” layout with trig scales on back of closed frame stock - part of mini Secondary School series


0252 BetaSchool Technical two-tone

Cheaper construction​ & possible OEM by FUJI - part of mini Secondary School series


0253 Gamma School Technical two-tone

Cheaper construction​ & possible OEM by FUJI - part of mini Secondary School series


0254 DeltaSchool Technical/Log-Log two-tone

Cheaper construction​ & possible OEM by FUJI - part of mini Secondary School series


0260Machining Time

Table of guidelines for turning speeds + 2 cursor windows in back


0270Technical long-scale

Table of constants on back + bigger sibling 0275


0275Desktop Technical long-scale

Tables of conversion factors + 2 cursor windows in back - long scales (folded @ Pi) & desktop model meant accuracy of 0.03% + smaller sibling 0270


0291 Polymath-DuplexTechnical/Log-Log

 OEM by FUJI but retailed through Hope Slide Rule Mfg. Co. - see also smaller 0129 sibling


0292 Multimath-DuplexTechnical/Log-Log two-tone
0320Petroleum two-tone - System Dr. Schmeling

​Specially marketed to Petroleum Industry for crude oil related calculations


0330Chemical two-tone

​Top 2 scales & top scale on back of slide = plethora of gauge marks = table of elements & molecular weights


0370Electro

Top non-standard scale is for rapid calculation of tension losses in copper wires + bottom non-standard scale is for calculating peripheral velocities (D scale displaced by pi/6 or 0.5326) - 2 cursor windows in back​ + bigger sibling 0375


0375Desktop Electro

Top non-standard scale is for rapid calculation of tension losses in copper wires + bottom non-standard scale is for calculating peripheral velocities (D scale displaced by pi/6 or 0.5326) - table of conversion factors & 2 cursor windows in back​ + smaller sibling 0370


0408Finance two-tone
0432Reinforced Concrete - System Dr. Schaeffer

Stress factors 1200 & 1400kg/cm2 of iron on either side of slide


0440Reinforced Concrete two-tone - System Maarschalk

​Designed by Dutchman M.C.M. van Maarschalkerwaart but Nestler felt his full surname was too long for the System accreditation & hence shortened it!


10Enhanced Mannheim

​German sliver screws + table of conversion factors on back + 2 cursor windows


11 (narrow)Pocket Enhanced Mannheim

extremely narrow & Lilliput-like footprint with no model/maker markings on rule + 2 cursor windows in back​


11 (ver. 1)Pocket Enhanced Mannheim

German silver screws + Table of conversion factors & 2 cursor windows in back


11DPocket Darmstadt

Broader than other in 11xx series​ 2 cursor windows in back


11EPocket Enhanced Mannheim

orange/dirty-brown celluloid with 2 cursor windows in back


11MPocket Enhanced Mannheim

2 cursor windows in back​


11OPocket Mannheim

unnecessarily 2 cursor windows in back​


11RPocket Rietz

2 cursor windows in back


11ZEPocket Electro

V & W scales in well of stock + 2 cursor windows in back


11ZMPocket Enhanced Mannheim

2 cursor windows in back


11ZRPocket Rietz

Model no. etc on back + 2 cursor windows


12Pocket Enhanced Mannheim

cm & inch scale on back + 2 cursor windows


12aPocket Enhanced Mannheim

unmarked but reseller, P. Trumel, in well of stock + table of conversion factors on back + 2 cursor windows


12bPocket Enhanced Mannheim

cm scale in well of stock + table of conversion factors on back + 2 cursor windows + unusual combination of magnifying cursor & extra tick marks emulates precision of 25cm model  


12cPocket Enhanced Mannheim

cm scale in well of stock + table of conversion factors on back + 2 cursor windows


17Extra long Enhanced Mannheim

Unusual length + railway track scales + German silver screws + cm scale in well of stock


18Desktop Enhanced Mannheim

cm scale in well of stock + tables of conversion factors on back


20/1 KielRietz

Kiel name (like F-C 1/94) comes from being the model favoured by German Imperial Naval Academy & School Kiel  - table of conversion factors on back + 2 cursor windows​


21Darmstadt

​Owned & used as a student by legendry Swiss collector Heinz Joss - 2 cursor windows in back


21aDesktop Darmstadt 360°

cm scale in well of stock + table of conversion factors on back


22Extra long Pocket Rietz

cm scale in well of stock + table of conversion factors on back + 2 cursor windows


23Rietz

cm scale in well + table of conversion factors on back + 2 cursor windows


23a (A/R)Desktop Rietz - late

Unusual scale length​ - tables of conversion factors on back


23RRietz

cm scale in well + table of conversion factors on back + 2 cursor windows


23R/3Rietz

table of conversion factors on back + 2 cursor windows


23R/3Rietz - early

table of conversion factors on back + 2 cursor windows


24Desktop Rietz

cm scale in well of stock + tables of conversion factors on back - ex Shell (B.P.M.)


24bExtra long Desktop Rietz long-scale

Not demonstration type but 10f only 4 engine-divided (only maker capable of desktops >50cm) + early production year from 1908-1911 style of company name - read more ....​


24RDesktop Rietz - late

cm scale in well of stock + tables of conversion factors on back


24R/1Extra long Desktop Rietz long-scale

Not demonstration type but 1 of only 4 engine-divided 100cm models (only maker capable of engine dividing desktops >50cm)​


26Business & Machining

Table of machining speeds on back + 2 cursor windows


27Technical long-scale

C & D long scales folded @ Pi + S & T also long-scale + cm scale in well of stock + tables of conversion factors on back & two cursor windows + see also larger sibling 


27aDesktop Technical long-scale

C & D long scales folded @ Pi + S & T also long-scale + desktop model meant accuracy of 0.03% + cm scale in well of stock+ tables of conversion factors on back - long scales (folded @ Pi) & - see also smaller sibling 


28Universal Stadia Topography - 360g

German silver screws - table of conversion factors on back + 2 cursor windows + see bigger sibling


28aDesktop Stadia Universal Topography - 400g

Tables of conversion factors on back - model later replaced by 0286 Geometer + see smaller sibling


3Mannheim

SUPPLIED BY ASTON & MANDER LONDON in well


31Timber

For all aspects of timber industry (round & square timber ) - same model used by Albert Nestler (1851-1901) to calculate raw material needed for making wooden slide rules - cm & inch scales + 3rd party name Vollmer-Werke A.G.


33Chemical

German sliver screws - table of atomic weights on back


33Chemical - early

​Narrow stock - German sliver screws - table of atomic weights on back + 1 cursor window


37Electro

Top non-standard scale is for rapid calculation of tension losses in copper wires + bottom non-standard scale is for calculating peripheral velocities (D scale displaced by pi/6 or 0.5326) - table of conversion factors on back + 2 cursor windows


37Electro - early

Top non-standard scale is for rapid calculation of tension losses in copper wires + bottom non-standard scale is for calculating peripheral velocities (D scale displaced by pi/6 or 0.5326) + cm scale in well of stock + German silver screws - table of conversion factors on back + 2 cursor windows


37Electro - monochrome & early

Top non-standard scale is for rapid calculation of tension losses in copper wires + bottom non-standard scale is for calculating peripheral velocities (D scale displaced by pi/6 or 0.5326) + monochrome with no CI but cm scale in well of stock + German silver screws - table of conversion factors on back + 2 cursor windows


37/15Extra long Pocket Electro

Top non-standard scale is for rapid calculation of tension losses in copper wires + bottom non-standard scale is for calculating peripheral velocities (D scale displaced by pi/6 or 0.5326) + cm scale in well of stock - conversion tables on back + 2 cursor windows​


37aDesktop Electro

German silver screws + cm scale in well of stock + Table of constants on back


39Pocket Electro - Sytem Besser

39 is one of the model no.‘s Nestler illogically reused for 2 totally different types + extremely unusual layout of scales (DBGM for Erwin Besser) + table of constants on back ​


4Enhanced Mannheim

​Retailer’s name also in well


40Retail & Monetary

Unusual incised scales + 1 cursor window in back 


40Retail & Monetary - classic

German silver screws + table of conversion factors & 1 cursor window in back


40Retail & Monetary - early

Narrow stock & probably earliest model specifically made by any maker for commerce + ​German silver screws + 1 cursor window in back


40aDesktop Retail & Monetary - late

Unusual scale layout + British pound sterling (£ s d) scales on back of slide + conversion tables on back


41Lilliput Enhanced Mannheim

cm & inch scale on back + 2 cursor windows​


42ZLilliput Mannheim

unnecessarily 2 cursor windows in back


43Reinforced Concrete - System Hoffmann

Stress factors 1200 & 1400kg/cm2 of iron on either side of slide + table of factors on back & 2 cursor windows


45Desktop Basic long-scale

Largest of only 3 cylinder/drum models


5Mannheim

Table of conversion factors on back painted white


7Business

Table of conversion factors printed on back - cheaper construction (e.g. no German silver screws) but still quality finish


8Rietz

Table of conversion factors on back painted white


9Rietz

2 cursor windows in back


939 HoehenwindmessungDesktop Military Artillery Range Finding/Meteorology

Modern day 360 degree Winkel in Grad version of High Altitude Calculator for German Armed forces (NATO NSN No.: 6660-12-127-6307) for global missile trajectories or possibly jet stream & its effect on missiles or planes flying at high altitude + read more ...


A.B.C.Military Tank Artillery

Special commission for L’arme blindée et cavalerie (ABC) or Armoured Cavalry Arm of French Army + 2 unnecessary cursor windows in back


ABCPocket Military Radiation

Specially commissioned fallout calculator for German Armed Forces (NATO NSN no.: 6665-12-136-1506) & ABC = Atomic, Biological & Chemical -- table on back lists battlefield fallout compensation/reduction factors + read more ...


ABLMilitary Vehicle Logistics & Supply

Specially commissioned calculator for vehicles travelling in column formation made for the Belgian Army (ABL) but relationship to Westf. Versandhaus is unknown - Inch scale on back


GEAPocket Enhanced Mannheim

Specially commissioned by Bochum-based German supplier of air conditioning and refrigeration technology Gesellschaft für Entstaubungsanlagen (GEA AG) + railway track scales & German silver screws + table of constants & 2 cursor windows in back 


GlanzstoffPocket Textile

Specially commissioned by Vereinigte Glanzstoff-Fabriken AG + company name & logo’s on back + more textile constants + 2 cursor windows


Hermann SchubertPocket Textile

Specially commissioned by the Zittau-based leading German sewing thread supplier Herman Schubert + ​deceivingly nondescript Mannheim layout was later granted a German DRGM registered design (1454414) on 18-11-1938 because of the thread size table on back & later modified cursor


Landis & Gyr (11O)Pocket Mannheim

Unmarked 11O special commission for Landis & Gyr A.G. - co. name printed on back with two unecessary cursor windows


Landis & Gyr (11ZR)Pocket Enhanced Mannheim

Unmarked 11ZR special commission for Landis & Gyr A.G. - co. name printed on back with two cursor windows


LuftwaffenamtMilitary Time-Speed-Distance for aircraft

Special commission for German Luftwaffenamt (Air Force) + German sliver screws - continuation of 1:30000000 top-edge scale in well +  blind stamp in back indicates military provenance 


RL 130Mannheim-like

Pre-engineered generic model made here for German Friedrich Krupp AG - back of the cursor innovatively doubles up as a clip for jacket or shirt pocket + read more ...


Sydema CorpometerBespoke Tailoring Aid

Special commission consisting of a 4-part ruler (one part missing) possibly for Wolterstorff to measure the size & shape of the female form for a made-to-measure jacket/coat  


Sytem RietzRietz

Special commission possibly for British maker/retailer A.G.Thornton but with a stock width associated more with a Mannheim type - table of constants on back + 1 cursor window.


Total StralenschutzPocket Radiation

Non-military ABC (Atomic, Biological & Chemical) fallout calculator specially made for German company: Total KG Foerstner & Co.


Norden
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(NoName) Pocket Mannheim

NIFE (Swedish company set up by Georg Vogel to manufacture optical products) logo stamped on back - company name derived from battery components Nickel (Ni) and Iron (Fe)


(NoName)Pocket Rietz

Unusual layout of the scales


2/48Darmstadt

Appears well made


NORMA-Mechanik
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Gambrinus 100Pocket Beer Brewing

Gambrinus = European folklore entity & icon for beer & brewing - easier to use than contemporary beer brewing rules from F-C, Nestler, etc + company name & logo for “Ziemann Brauerei” on back


Grafia 100Pocket Basic Paper

Many paper/graphics gauge marks & industry specific factors such as datum marks for DIN sizes


Grafia 190Basic Paper

Hanging/floating cursor + many gauge marks + many paper/graphics industry specific factors such as datum marks for DIN sizes


Mekuria 190Business

Inner ring has many gauge marks for imperial-based conversions


Simplex 100Pocket Basic

Too basic to have the typical hanging/floating cursor + simple raised lug for moving inner disc ​


Norwood Enterprises
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FPB-120Desktop Music Composition

Slide chart copyrighted design & trademarked DIAL-A-CHORD name


Oahu Publishing Co.
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Magic Music GuideMusic Guitar Chords

Slide chart with copyrighted design by John De Paul designed specifically for Hawain guitar


Oertling, Ludwig
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Excise 2611Alcohol Saccharometer set

Scales runs from 0 to 30 + 5 weights calibrated in steps of 30 from 1000 to 1120 but missing thermometer


OHICO
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Electro 15Electro

OEM version made by KHH (5 slits in well + 5 adjustment screws on botton side edge) but often mistaken as Dennert & Pape because of model no. - V & W scales in well of stock + conversion tables (in NL) on back - see also identical model sold by Ahrend & Kahn


Otto Meuter Rechenmaschinenfabrik
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PRODUXPocket Slide Adder - gold/black

Original version but being shorter adder bars are exposed when calculating + with no mechanical clear/reset function exposed adder bars are instead slid back up by pushing on a flat surface - e.g. a table top ​


PRODUX STPocket Slide Adder - green

Being shorter adder bars are exposed when calculating + with no mechanical clear/reset function exposed adder bars are instead slid back up by pushing on a flat surface - e.g. a table top


Oxford University Press
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Musical Slide RuleBook Music

Design of rule & book by tonal fanatic Llewelyn Southworth Lloyd (1876-1956) as introduction to fundamentals of musical scale​s & intervals - works in the same simple way as Oughtred’s original invention + shows & uses relationship between mathematics & music - slide rule in back


Pan American Band Int. Co.
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SimplexMusic Fingering for Flute and Piccolo

Slide chart copyrighted design published by American Mills Music Inc.


PENOL
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1005ARietz-like

Unusual & more convenient for a Rietz all scales on front face + Pen Ol(sen) was nickname for Danish founder Christian Olsen & reflects their primary product: fountain pens (incl. Parker's under licence) 


102AEnhanced Mannheim

Inch scale reverted + Pen Ol(sen) was nickname for Danish founder Christian Olsen & reflects their primary product: fountain pens (incl. Parker's under licence) 


521APocket Enhanced Mannheim two-tone without Trig scales

Pen Ol(sen) was nickname for Danish founder Christian Olsen & reflects their primary product: fountain pens (incl. Parker's under licence) 


Philips Electrical Ltd.
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Planned Lighting CalculatorLighting

​Used to calculate lighting costs & how to reduce them 


Pickett & Eckel
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Chords & KeysMusic Composition

Slide chart copyrighted design by Lynn T. Harris for organs, pianos & accordions - surprisingly made by manufacturer better known for its aluminium slide rules


PlantijnCasparie
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ECLIPS PLANISFEERDesktop Astronomy - Northern Hemisphere

Slide chart designed as planisphere by Dutchman R. Walrecht to calculate star positions in Northern Hemisphere for given date & time but in a special eclipse of the sun (11/08/1999) edition showing positions of sun, moon, planets & perseids meteor storm + based on version made by ALRO


PLASTOGRAF
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Academica Pocket Rietz

Almost certainly made by little known Brazilian maker but unusually instead San Paolo under company name it is Ind. Bros. - one open left-hand window with 1 hairline in back​​


Posterijen, Telegrafie en Telefonie (PTT)
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CWP 11Cable Radio

Well of stock & slide both shaped as isosceles trapeziums (CWP = centrale werkplaats/central workshop) + used to calculate signal loss in dB for a national cable radio broadcasting system offered to homes in The Netherlands from 1930 to 1970 - read more ...


Premia
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QuartzWristwatch Calculator Basic

Probably a CASIO or Citizen “lookalike”​


Prometheus/Prometei/Prometejs - Leningrad
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Model 1Rietz - early

Prometheus = English version of Russian company names + hand-written serial no. = 7435 (also on back of slide) + nothing in well of stock = early model + conversion factors & formulas on back ​


Refinery Supply Co.
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AC-ME Pocket CalculatorPetroleum Gas Flows for Orifice Meters

OEM by Nestler (style of Pi + MADE IN GERMANY on back) + AC-ME = Ac-curate Me-asuremet Precision Instruments (? designers) + version  by Pickett & Eckel (1080-T)


Reiss
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(NoName ver. 1)Artillery Range Finding

Maybe VEB MANTISSA made or transition model because of typical MANTISSA case & cursor


(NoName ver. 2)Artillery Range FindingEarlier (or later) ver. 1 is open frame & has a cm bevelled edge scale but no extra D scale on back of stock.
(NoName)Artillery

For calculating the amount of charge needed/range in meters for various types of charge - has no slide!


(NoName)Dummy

Showroom model (slide fixed) or possibly representatives sample


(NoName)RietzCostly “over engineered” construction to accommodate bevelled edge cm scale & supplementary mini-cursor
3223Progress log-log

Progress type = refinement of two earlier Robert Reiss’ extended scale ideas - well-engineered slide rule with unusual scale layout


Reliable Typewriter & Adding Machine Corp.
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ADDOMETERDial Adder

Extended 8 dial design (no serial no.) for simple arithmetic & based on original Pascal adding machine. 


ADDOMETERDial Adder Monetary

Serial no. 021501 & retailed by Tailors (UK) extended 8 dial design for pre-decimal calculations in British £sd & based on original Pascal adding machine. 


Reliance Nameplates Ltd
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Rule Slide 10"Enhanced Mannheim

top & bottom side edges reinforced with metal  mesh - two windows, conversion table, helmeted head logo & UK government broad arrow mark on back


Ricoh / Relay Keisanjaku
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102Enhanced Mannheim

Metal backing plate + Table of constants & cursor window with 1 hairline in back


120Darmstadt

Metal backing plate + Table of constants & cursor window with 1 hairline in back


403 (Relay)Lilliput Enhanced Mannheim

Metal backing plate + Table of constants & 1 cursor window with + 1 hairline in back


403 (Ricoh)Lilliput Enhanced Mannheim

Metal backing plate + Table of constants & 1 cursor window with + 1 hairline in back


505 (Relay)Pocket Enhanced Mannheim

Table of conversion factor & 1 cursor window with 1 hairline in back 


505 (Ricoh)Pocket Enhanced Mannheim

Table of conversion factor & 1 cursor window with 1 hairline in back 


80Mannheim

Metal backing plate


Rijnja, P.
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BeamsWooden Floor & Ceiling Beams - System Van Gerven

Tailor-made blank & cursor Hans Seehase but Rijnja added the scales - in this design Van Gerven included adjutment for beams bowing - table of building construction standard reference values in well of stock


Beams - basicPocket Wooden Floor & Ceiling beams - System Van Gerven

Tailor-made blank & cursor by Hans Seehase but Rijnja added the scales - table of building construction standard reference values on back


ConcreteReinforced Concrete Floors - System J.L.H. Strackee poly-slide (2)

Tailor-made blanks supplied by Hans Seehase but Rijnja added the scales


RiSta (H.Stam)
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darmstadt 3Darmstadt

riSta = ri(chel)Sta(m) - OEM rule probably made by UTO - two cursor windows + hairline in back


darmstadt 33Pocket Darmstadt

riSta = ri(chel)Sta(m) - OEM rule probably made by UTO - give-away from CONTROL DATA Corp - two cursor windows + hairline in back


rietz 1Rietz

riSta = ri(chel)Sta(m) - OEM rule probably made by UTO


rietz 11Pocket Rietz

riSta = ri(chel)Sta(m) - OEM rule probably made by UTO


Robson & Co., F.
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(NoName)Desktop Steel & Iron Weight Calculator - imperial

One of earliest weight calculators for rectangular & square section bars from little known UK (Newcastle on Tyne) instrument maker/optician 


Rodgers, J.N. Ltd.
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Musician'sMusic Composition & Transposer

Slide chart designed for constructing chords, transposition and general music theory


ROYAL
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1503School Darmstadt two-tone

OEM by Uchida - cm & 1/20 inch on back


Rudolf Bauer & Co.
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FedraLog-Log

OEM model probably made East German VEB MANTISSA uncommonly is a closed-frame duplex model - i.e. back of slide just has Greek symbols & names for 1 to 20 for show + notch on top of right-had end to stop cursor falling off


Ruxton Multi-Vider Corp.
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Multi-Vider (Standard)Pencil Basic

Mechanical drop-lead patented (FR670320) pencil incorporating an octagonal split-cylinder slide rule barrel


RUYI (Si Da Rule Factory)
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1015-1Log-Log Hyperbolic

Grey end braces


1083Log-Log Hyperbolic

Adjustable screws in metal end braces + similar to K&E 4083-3


S.R.&S.E. (Slide Rule & Scale Eng. Co.)
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KoehringConcrete Quantity Calculator

For calculating no. of batches need to concrete over a specific area when using particular models of Koehring & KwikMix pavers/mixers - design by G.L. Lockhart & copyrighted 1948


REDI-MIXCircular Construction CU.YD. / Concrete Calculator

Unusal duplex construction with two (front & back) closed frame slides - copyrighted design + patent applied for


Victor L. PhillipsConcrete Quantities and Areas

Calculator for computing imperial concrete quantaties & areas with company details on back - copyrighted design


W.H. PipkornBrick & Tile

1940 copyrighted design for determining bricks or tiles (also other masonary units) needed/used to build a wall of given dimensions (l x h) - tables on back show various types & sizes of masonry units + wastage


SANTOK / SANTOKU
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(NoName)Pocket Rietz

Unbranded


(NoName)Technical two-tone

Unbranded apart from case


93Pocket Enhanced Mannheim without Trig scales
Schacht & Westerich
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2771 System Cuntz (ver. A)Pocket Complex Number

Made by KHH - inch & cm scales on back - patented design (US1168059 & D.R.G.M. 536689) by Gregor Cuntz - sophisticated scale arrangement to keep the orders of magnitude of numbers in line that sadly failed in the market


Scientific Instruments Company (SIC)
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4030Lilliput Enhanced Mannheim

Serial No 30842 + Table of conversion factor & 1 cursor window with 1 hairline in back 


Scientific Publishing Co.
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Type T (2BT1)Pocket-Watch Textile

Transition model as company name changes to Fowler - yellow lens face - two milled winders (one with crown ring) - table of weaving-related values on front face + table of weaving-related factors on back​


Seehase, Dr. Ing.
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(NoName)Pocket Mannheim

Model often used as a promotional gift/giveaway with a company name/logo on the back


ConversionPocket English and German MeauresIncorporates 34 different imperial to metric conversion “gauge marks/factors
System SchirdewanTextile

Used in a leading textile factory of the day Scherg (Brasov, Romania) + tables of constants on back - read more ...


Seger
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No. 52DarmstadtName “Seger” & “MADE IN NORWAY” blind stamped in well of stock + indistinct blind date-stamp on back = lookalike Norwegian-made copy of Faber-Castell 111/54?
Service Slide Rule Co.
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ElectroLog-Log

Although called an Electro the scale layout does meet the Bob Adams criteria for this type & PS gauge mark is wrong 746 = HP + table of conversion factors on back + 2 cursor windows - read more ...


ReedElectronic Engineers

innovative gauge marks + D/L (Diameter to Length) Nagaoka coefficient scale in well + table of conversion factors & 2 cursor windows in back - read more ...


Servo Calculator Co.
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Boonshaft & FuchsDesktop Control Engineering

After preloading 11 of 25 removeable slides the chosen scale layout can "simply" calculate overall amplitude ratio & phase of a multiterm transfer function


SHUBB
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TG1Pocket Music Guitar Transposer

​Slide chart for transposing chords & placing guide for a capo on guitar fingerboard + UPC 700682010013 or EAN 0700682010013 barcode numbers - still sold


SIMI
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154/47DarmstadtName “SIMI MALMÓ” & “MADE IN SWEDEN” printed in well of stock & on box = lookalike Swedish-made copy of Faber-Castell 1/54 (even the model numbering!) but not of the same quality
Smallwood, I & D (John & Daniel)
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(NoName)Folding Shoe Size Stick - metric

For French shoe sizes 10-48 in increments of a Paris point (⅔ cm) + not only folding but when closed, heel rest & slinging toe marker lock the stick folded


SPZ - Voronezh
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NL-10mAviation

Flight Computer + identical model made by another Russian factory - LFAI ​


Staedtler-MARS
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544 28Log-log

OEM Nestler Multimath Duplex 0292


544 ATechnical

Probably made by Fujj (F-100) - unusual choice of scales & layout common to Japanese makers - possibly retailed as a package with OHP version


544 A AVDemonstration OHP Technical

Unusual choice of scales & layout - only other known examples are from Japanese makers - overhead projector version for model 544 A


Standardgraph
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900Basic/Conversion

​clever interaction of conversion gauge marks & scales on front - table of conversion factors on back 


Stanley Rule & Level Co. (USA)
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Carpenter Timber No. 12Joint 2-fold Old Arched-hinged Coggeshall

D Girt line = 4-40 + four-entry ¼ to INCH scale table on front + ¾-length E & M scales (split over 2 legs) on back


Carpenter Timber No. 46Joint 2-fold Large Plate-hinged Coggeshall

No D Girt line - unbranded but font & model numbering identical to Stanley (USA) but mysteriously only has B,C scales on front + ¾-length E & M scales (split over 2 legs) on back - or is it a later copy/forgery?


Stanley, W.F. (GB)
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(NoName)Pocket Rectangular Protractor/Diagonal Scale - imperial

Early 0-360 degree model as address is Great Turnstile, Holborn.


GoochDesktop Gauge for Centering poly-slide (2)

Invented & patented (GB189313940 - 1894) by Charles Gooch as an impoved gauge for centering & mounting photographic prints et al - the 2nd slide is attached on top of the slide in the stock by means of a metal sleeve/clamp ​


M3613 Professor Fuller's Type 1Desktop helical long-scale

Patented (GB187801044 & US219246) design by George M. Fuller - serial No. 4869 with conversion tables, natural sines & Birmingham Wire Gauge on inner fixed cylinder


M3656Enhanced Mannheim
M3686Electro

For Electrical or Mechanical Engineers - V & W scales in well of stock - table of conversion factors on back


M3689 Student Mannheim

Cheaper version (celluloid facings only one front face) of M3656 - MADE IN ENGLAND and STANLEY LONDON stamped on slide


Pilot Balloon Mark IIDesktop Meteorology

Meteorological Office (MO) No. 1979/43 - possibly made for Stanley by J.J. Hicks or A.G. Thornton - adoption of standard rates of ascent removed need for Mark I poly-slide (2) but 4th cursor needed for “tail method”


Professor Fuller's Type 0Desktop helical long-scale - early production

A 48th Wedding Anniversary present from Ros - patented (GB187801044 & US219246) design by George M. Fuller - hand-held early shorter version with no spigot & no serial no. + conversion tables, natural sines & Birmingham Wire Gauge on inner fixed cylinder


W.H. GlaserDesktop Textile Conversion poly-slide (2)

Unusual fixed cursor extending the range of a relatively short scale length - read more ...


Sterling Plastics (USA)
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(NoName)Pocket Octal/Hexadecimal calculator for computer programmers

Based on 1973 American patent US3716186A (Kent B. Comfort) - promotional give-away for Environmental Dynamics Inc. (EDI)


556 Multiply-RulerChild's Teaching Aid/Calculator for Simple Arithmetic

Simple arithmetic slide calculator & pencil sharpener


587Pocket Enhanced Mannheim

Typical raised moulded back of stock


Dial-A-MaticDial Adder

Basic 4 dial design based on 1957 patent (US2797047) by Otto Springfield for simple arithmetic ​


PrecisionEnhanced Mannheim

Typical raised braces & pillar supports part of the stock


Stevens Engineering Co.
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Rally Indicator - model 25 Time-Speed-Distance rallying calculator California based maker specialising in rallying equipment, clocks, etc - road rallying tool popular in North America - long metal arm = “T” + 2 short metal arms = “E” & “M” - imperial/metric conversion table on back
Stichting Jazz Beheer Amsterdam
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AccoordenschuifMusic Chords

Post-WWII Amsterdamse Jazz Club was a nightspot for traditional jazz that later became a non-profit foundation for jazz-related projects as this educational slide chart for learning to improvise through choice of chords + developed by musician, game creator & foundation member Fred Hoorn + it was accompanied by a book & cassette of musical examples


Sunrise - Moscow
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Krougovaia Logarifmioueskaia KL-1Pocket-Watch Basic

Model name = Circular logarithmic in Russian + black dotted winder for A & C scales wheras red dotted winder moves both pointers simultaneously ​


Systeem Matthijssen
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370Desktop Technical

Use/purpose of the many gauge marks is unknown - SR built into desktop stand for Nederlandse Kabelfabriek (NKF - Dutch cable factory in Delft)


386Desktop Technical

Possibly a basic model for other specially commissioned designs but use/purpose of the many gauge marks is unknown - SR built into desktop stand


412Desktop Transport

​Commissioned by Coöperatieve Condensfabriek Friesland (CCF a Dutch dairy specialising in condensed milk) - for checking the waybills for shipping/tranporting goods   


Tavernier-Gravet
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(NoName)Desktop Pipe Flow - System Aisenstadt

​Narrow body design by E.A. Aisenstadt & date stamped in back


(NoName)Rietz

Left & right small window with cursor lines in back - paper table on back missing​


L. MosséHeating

L. Mossé was a leading French academic on heating


Technical Sales / Emblem
ModelTypeCommentsThumbnail
1051 TUTOR Technical two-tone

OEM by Uchida


1053 OLYMPIC LLDarmstadt two-tone

OEM by Uchida - cm & 1/20 inch on back


1071 COMMERCIALMonetary two-tone

OEM by Uchida -  ​£-s-d on back


1081 TECHLOG Log-Log two-tone

 OEM by Uchida


Tecnostyl
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41/RPocket Rietz

Promotional gift from office furniture supplier: ASPA ​


CalcolatorBasic - early

Novel graduated ring of raised marks to aid lining-up/turning inner disc ​


CalcolatorBasic - late

Novel graduated outer ring to aid lining-up/turning inner disc + gauge marks added to later more colourful version ​


TEKNOR
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1051 GrundskolaTechnical

Swedish retailer selling an OEM by Japanese maker Ushida Yoko + unusual layout for entry or Elementary School model


1081 GymnasiumLog Log

Swedish retailer selling an OEM by Japanese maker Ushida Yoko


525Pocket Mannheim

Swedish retailer selling an OEM probably by Danish maker UTO


57/KPocket Rietz

Swedish retailer selling an OEM an OEM probably by Danish maker UTO + 1 cursor window in back 


Thomas Hart Ltd.
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Lambeth Horse Power CalculatorSpeed

Promotional giveaway (possibly part of a series) for finding the HP needed for steam engines driving a line shafting set-up in a factory - design possibly by Pickworth - table on back for max HP for ropes of a given diameter/weight


Thomlinson, C.J. Ltd
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Equivalent Paper Slide Scale"Pocket" Paper poly-slide (2)

Extensively used in paper making industry - uneven alignment of letters and numbers


Thornton A.G. / P.I.C. / British
ModelTypeCommentsThumbnail
A.G. (NoName)Desktop "prototype"

Unbranded but attributable to Thornton (horizontal/flat diamond box identification marks & reversed bottom edge scale) - traditional B scale replaced by upward pointing arrow - read more ...


A.G. (NoName)Poly-slide (2) Steel Weight Calculator

Possibly made by D&P (Pi symbol) for naval steel shipbuilding where all weights in construction are recorded to calculate final displacement.


A.G. ClementsonWater Pipe Sizing

Bottom “duo” scale for pipe diameters according to Rietschel formula (in black) & according to Meier formula (in red) - table on back for friction equivalents in various fittings


A.G. D6957Improved Perry Log-Log

Made by Nestler (German silver screws + DRGM 164885 in well) with top edge 1/50ths inch scale for steam engine indicator diagrams, bottom rare Perry scale (0.91-10-4) patented (GB190123236) = reciprocal variant of LL (e-1) & Inch scale in well of stock + A.G. Thornton Manchester + conversion tables on back


A.G. English ElectricLilliput A.C. Power Factor Electro

Specially commissioned by English Electric Co. + B1 & C1 Power Factor scales (A.J. Riches patent GB520442) on back of slide easily mistaken for reciprocal BI & CI scales - read more ...


British 0552/1448Naval Time-Speed-Distance calculator

Later version of model Pattern 1448 with identical scale layout & labelling but obviously without the UK government upward arrow mark 


British AD 050School Differential Log-Log

Extra Thornton patented differential Trig scales ≡ to model P271 - superseded by model AD 150


British AD 060Standard

≡ to model P281


British AD 070Rietz

Rietz type without Trig scales


British AD 150Log-Log

Later replacement for model AD 050


British P221Differential Comprehensive Log-Log

Extra Thornton patented differential Trig scales & Vector analysis scales - superseded by model AA 010


British P271School Differential Log-Log

Extra Thornton patented differential Trig scales - superseded by model AD 050


British P281School Standard

superseded by model AD 060


PIC (NoName)Pocket Mannheim

Advertising “give away” for High Duty Alloys Ltd, Slough, UK​


PIC 111/PC 8Differential Rietz

Rietz type without Trig scales but with extra Thornton patented differential Trig scales - conversion tables on back


PIC 112Desktop Differential Rietz

Rietz type without Trig scales but with extra Thornton patented differential Trig scales - conversion tables on back - “big brother” version of PIC 111


PIC 120Pocket Differential Log-Log

Extra Thornton patented differential Trig scales - “kid brother” version of PIC 121


PIC 121/PC 18Differential Log-Log

Extra Thornton patented differential Trig scales & Vector analysis scale - conversion tables on back


PIC 122Desktop Differential Log-Log

Extra Thornton patented differential Trig scales - conversion tables on back - "big brother" version of PIC 121


PIC 131Differential Electro

Extra Thornton mini Y & Z scales for financial calculations + patented differential Trig scales + Vector analysis scale - V & W scales in well of stock (metal well cursor) - conversion tables on back


PIC 131/PC 18Differential Electro

Extra Thornton mini Y & Z scales for financial calculations + patented differential Trig scales + Vector analysis scale - V & W scales in well of stock (plastic well cursor) - conversion tables on back


PIC 132Desktop Differential Electro

Extra Thornton mini Y & Z scales for financial calculations + patented differential Trig scales + Vector analysis scale - V & W scales in well of stock (plastic well cursor) - conversion tables on back - “big brother” version of PIC 131


PIC 141 (Model E)A.C. Electrical Electro

Designed for calculating with vector quantities - front face has Trig scales, rapid √squares of 2 numbers scale & temperature resistant (°C & °F) copper scales - angle to Log conversion scale on bottom edge - conversion tables on back + see also PIC 144 sibling


PIC 144 (Model F)A.C. Electrical Electro

Designed for calculating with vector quantities - front face layout has Trig scales, rapid √squares of 2 numbers scale & temperature resistant (°C & °F) scales for Copper - Angle to Log conversion scale on bottom bevelled edge - conversion tables on back + see also PIC 141 sibling


PIC 221Differential Comprehensive Log-Log

Extra Thornton patented differential Trig scales & Vector analysis scales - superseded by models P221 & AA 010


PIC 241Differential Log-Log

Extra Thornton patented differential Trig scales - identical to model no. 271


PIC 271School Differential Log-Log

Specially commissioned by Lennig Chemicals Ltd. before relocating to Croydon, Surrey in 1968 + extra Thornton patented differential Trig scales - claim SR made from “high impact acrylic oroglas t”


PIC F 3649Log-Log

“F” model no. prefix = mahogany - mini resistance of copper wire scale for temperature variations on back of slide - conversion table on back


PIC F 3651Desktop Electrical & Mechanical Engineer Electro

V & W scales in well of stock - conversion tables on back of stock


PIC F 3654Mannheim

Mini resistance of copper wire scale for temperature variations on back of slide - conversion tables on back


PIC F 3658School Mannheim

wooden back


PIC F 3756Desktop Mannheim

conversion tables on back


PIC F 4865Engineer Commerce Electro

V & W scales in well of stock - mini Copper resistance scale on back of slide - conversion tables on back of stock


PIC JuniorSchool Mannheim

wooden back


PIC P251Standard

“P” prefix = plastic - oddball PIC


PIC Pattern 1435Naval Time-Speed-Distance calculator

Upward arrow preceding model no. on front face is UK government mark + all time related scales black & all speed/distance related scales red - identical front scale layout as Pattern 1448 sibling BUT missing Longitude (D.Long) scale on back of slide


PIC Pattern 1448Naval Time-Speed-Distance calculator

Upward arrow preceding model no. on front face is UK government mark + all time related scales black & all speed/distance related scales  red BUT unlike Pattern 1435 sibling has a Longitude (D.Long) scale on back of slide for converting between degrees & nautical miles


PIC Rule SlideMilitary Gunnery Royal Artillery

Extra gunnery gauge marks - typical 2 cursors (in case 1 gets lost!) for military version


PIC StandardMannheim

Mini resistance of copper wire scale for temperature variations on back of slide - conversion tables on back


PIC Standard Rule Slide Mannheim Royal Artillery

trig formulae on the back + “R.A.” for Royal Artillery


PIC VF 0123Mannheim Military

“VF” model prefix on back of stock = military - mini resistance of copper wire scale for temperature variations on back of slide - identical to standard Mannheim - conversion tables on back


PIC VP114/PC 1Pocket Differential Rietz

VP prefix = Vest Pocket - Rietz but patented (GB411090) differential Trig scales - cm scale on back


Tiger Toys
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DurfordDemonstration Mannheim

Smaller of two models made & name comes from Durford Mill where the company was located + accurate for a demo rule having 4 spring-loaded tensioning metal balls in bottom slide track


Tombeur
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A2Advanced Juggler's - System Tombeur

Specialist/advanced rule for throwing patterns & juggling mechanics. Serial no. 004 blind-stamped in back.


Radix 2/10Desktop Log - System Leibniz

Decimal/10-bit binary (base/2/base 10) rule. Serial no. 019 blind-stamped in back


S3Pocket Simple Juggler's - System Tombeur

Simple rule for throwing patterns & juggling mechanics. Serial no. 011 blind-stamped in back.


Trascacco
ModelTypeCommentsThumbnail
(NoName)Music Guitar Chords

Slide chart designed by Gianluca Govoni - still sold


Trebb Sales
ModelTypeCommentsThumbnail
Chord-O-MaticMusic Guitar Chords

Slide chart with registered designed specifically for Spanish (flamenco) guitar


Troeger (Hans)
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(NoName)Desktop Pricing long-scale

Uncannily similar (visual & construction) to much earlier Swiss-made Lightning Calculator (Blitzrechner) of Ernst Billeter - extra % scale for discount &/or profit margin mark-up calculations - son of K. Emil Tröger who took over the company his father founded


Troeger (Karl Emil)
ModelTypeCommentsThumbnail
Lung Volumes and BreathingDesktop Medical long-scale

Standard values of AG Pathophysiologie d. Atmung - “1” in equilateral triangle = East German (DDR) post 1950 certification mark for “1st or good quality” - Karl Emil founded the company later taken over by son Hans - 8 mini specialist scales overlaid on D scale


Neues Deutschland (ND)Desktop Typography printing - System B. Burghardt

Unmarked but obviously Karl Emil made - Neues Deutschland = East German daily newspaper - Cicero is a typographic unit of measure similar to a pica but with 15th century origins


No. 1 (ver. 37/393/6004) Desktop Basic+ long-scale

1” in equilateral triangle = East German (DDR) post 1950 certification mark for “1st or good quality” - Karl Emil founded the company later taken over by son Hans


No. 2 (Haefele)Basic

For G. Haefele spinning & weaving mill - Karl Emil founded the company later taken over by son Hans but NOW operating out of same Kirchenthumbach address (see instructions) - Haefele mill now private car museum (Patina)


No. 2 (ver. 37/393/6004)Basic

“1” in equilateral triangle = East German (DDR) post 1950 certification mark for “1st or good quality” - Karl Emil founded the company later taken over by son Hans


Trow, Isaac
ModelTypeCommentsThumbnail
Routledge EngineerJoint 2-fold Old Arched-hinged Coggeshall

D Girt line = 1-40 + “improved version” with gauge points & tables of engineering information on front + four-entry (split over 2 legs) INCH to ¼ scale table on back


TU - Kiev
ModelTypeCommentsThumbnail
125-10m Pocket Rietz

Equivalent ​ROCT (GOST) Russian State Standard No. = TY 25.01.610-72


250-10mRietz

ROCT (GOST) Russian State Standard No. = 5161-72


250-14mLog-Log

ROCT (GOST) Russian State Standard No. = 5161-72


Uitgeversmaatschappij Interland
ModelTypeCommentsThumbnail
ToonliniaalBook Music do-it-self scales

Dutch language book by Anne Klein Geltink for calculating scales, chords & transposing major & minor chord combinations with a do-it-self scale transposition rule in back ​


Unique
ModelTypeCommentsThumbnail

10G LegibleMannheim

Self-defeating innovation: less “tick marks” + more labelling = legibility but also less accuracy + table of trig conversion factors on back - read more ...


10L/L Log LogLog-Log

Table of decimal equivalents of fractions in well of stock & Trig tables on back


10L/L Log LogLog-Log - early

Early model made by Technical Supply Co - Trig tables on back


5G Legible Pocket Mannheim

Self-defeating innovation: less “tick marks” + more labelling = legibility but also less accuracy + table of trig conversion factors on back - read more ...


5L/L Log LogPocket Log-Log

Log Log type unhyphenated + no CI scale - Trig tables on back


5L/L Log LogPocket Log-Log - early

Early model made by Technical Supply Co - Trig tables on back


Area CalculatorPocket Surface Areas - imperial

For calculating areas of 2-dimensional figures or shapes in imperial square yards or square feet - bottom scales 2 parts of a single folded scale (folded @ 6 sq. feet)


B BrightonDarmstadt

Only Unique with Trig edge scales - despite unusual order of scales probably least unique Unique - table of decimal equivalents of fractions in well of stock & Trig formulas on back


C CommercialBusiness

Unconventional rule for merchants working pre-decimal & in imperial - conversion tables on back


Caterers and ConfectionersRetail Cost & Portion Control

Unusually the majority of the scales are calibrated for pre-decimal British £sd – a non-decimal currency that does not directly lend itself to a logarithmic scale.


Concrete Volume ComputerPocket Concrete

Made for Pioneer Concrete (UK) Ltd to calculate volume in cubic metres of concrete needed to fill conventionally shaped cavity (imperial or metric) - company name  on back


CostingMonetary - business

Copyrighted design for calculating (i) pre-decimal ​£-s-d & (ii) piece-rate pay - table of decimal equivalents of fractions in well of stock


CraftPocket Retail Costing

Despite the misleading model name a deceptively simple to use calculator for working in imperial feet & inches (l x w) of 2 dimensional areas + total pre-decimal cost for a given price/square foot for timber, sheet metal, hardwood, plywood, etc.​


D Dualistic High-Speed (1)Pocket Log-Log long-scale

Unusual mixture of long-scales & folded (√10) scales - table of Decimal Equivalent of Fractions in the well & tables of properties of materials on back - see bigger sibling


D Dualistic High-Speed (3)Log-Log long-scale

Unusual mixture of long-scales & folded (√10) scales - table of Decimal Equivalent of Fractions in the well & table of properties of Trig Ratios on back - see smaller sibling 


Double HLog-Log - prototype

Only known duplex model by Unique - name possibly derived from the profile of aluminium end braces - nonstandard scale layouts - simplex cursors glued back-to-back​


E ElectricalElectro - early

Unconventional layout (CF & DF & gauge points instead of W scale) - possibly made by Technical Supply Co. - Resistivity & Temperature Coefficient table on back


F FloridaEnhanced Mannheim

Extra narrow + imperial/metric conversion factors on back - model name possibly chosen for the US market - see smaller sibling  


F.S. Ratcliffe Spring CalculatingSprings poly-slide (2)

For helical tension & compression spring calculations - upper slide for stress & load/lower slide for spring rate + two tables & graph on back


F5 Florida Pocket Enhanced Mannheim

Extra narrow with no Trig scales- table of decimal equivalents of fractions in well of stock + trig ratios on back - model name possibly chosen for the US market - see larger sibling  


Five-TenPocket Mannheim long-scale

Double-length scales giving 10” precision - table of Trig ratios on back - see larger sibling


Friel-Sturdy Radiographic Exposure CalculatorRadiographic Exposure

For determining exposure times for medical X-rays - developed (prov. patent 29187/45) by two esteemed radiographers: Friel & Sturdy - table of conversion factors in well - table of bone densities (?) on back of slide - table of absorption values on back


Harfield Weight Calculator Steel - George Mancell

Extra narrow & made for George Mancell (London) Ltd to calculate (imperial) total weight of steel bars (l x Lbs/ft) + tables of conversion factors & calculating aids on back


Harfield Weight CalculatorSteel - Harrison & Whitfield

Extra narrow & made for Harrison & Whitfield (Steel Stockbrokers) to calculate (imperial) total weight of steel bars (l x Lbs/ft) + tables of conversion factors & calculating aids on back


Interval CalculatorCalendar

For calculating # of days between two dates in a year - table of decimal equivalents of fractions in well - conversion tables on back for pre-decimal Shillings & Pence to decimal £'s + Cwts & Quarters to Tons


JiffyLilliput Enhanced Mannheim without Trig scales

Unbranded - provenance of name possibly from “done in a jiffy” citation on cover of instructions - could be most cloned slide rule as many versions exist & UNIQUE was not known as an OEM supplier


M MonetaryMonetary

Stripped back version (fewer scales) of the Commercial - monetary scales (M1, M2 & M3) 3 parts of single folded scale (1d-£5000) – folded at 10/- & £50 - Table of decimal equivalents of fractions in well of stock


Mini-MannheimLilliput Enhanced Mannheim without Trig scalesParallel line logo
N NavigationalEnhanced Mannheim

Apart from linear edge scales for measuring distances on maps it has no specific air navigation-related scales but unconventionally has S & T scales on front face = ideal layout for general calculations - air & wind speed conversions factors on back


O Chemical Chemical/Log-Log

Parallel line logo + overall longer & wider than standard Unique 10” model for chemical volumetric analytical calculations - tables of chemical atomic weights (A to Zr) in the well of the stock & a table atomic numbers for elements up to Nobelium on back


Percentage ButtingMetal Seams

Made for Metal Box Co. (MB) as in metal can production the overlap is a key integrity factor of the finished product ​- % butting = amount of overlap in imperial inches needed for a sound seam - another version was made by BH


Pioneer Long ScaleDesktop ?? long-scale

Extra wide (3¼") ​body with mysterious non-standard  folded long-scales + 3 extra § scales in well & table of possible constants on back


Rolling Mill CalculatorSteel poly-slide (2)

Extra wide with nomogram in the centre for separating Force and Torque & made for Loewy Engineering Co. + based on 1973 UK patent GB659754 (Antolij Mogiljanskij) - company give-away to buyers of Loewy equipment


Rolling Mill CalculatorSteel poly-slide (2) - prototype

Extra wide with nomogram in the centre for separating Force and Torque & made for Loewy Engineering Co. + based on 1973 UK patent GB659754 (Antolij Mogiljanskij) - company give-away to buyers of Loewy equipment - given the style of text almost certainly a prototype version ​


Ten-TwentyMannheim long-scale

Double-length scales giving 20” precision - table of decimal equivalents of fractions in well of stock - various conversion tables on back - see smaller sibling


TER No.1 Cabling

1/5 set for calculating the Transmission Equivalent Resistance for 50 V. BALLAST in General Post Office (GPO) telephone cable design - overall longer & wider than standard 10” models - table of supplemental factors on back


TER No.2Cabling

2/5 set for calculating the Transmission Equivalent Resistance for 50 V. NON-BALLAST and SIEMENS No. 16 in General Post Office (GPO) telephone cable design - overall longer & wider than standard 10” models - table of supplemental factors on back


TER No.3Cabling

3/5 set for calculating the Transmission Equivalent Resistance for 40 V. C.B. in General Post Office (GPO) telephone cable design - overall longer & wider than standard 10” models - table of supplemental factors on back


TER No.4Cabling

4/5 set for calculating the Transmission Equivalent Resistance for 22 V. C.B in General Post Office (GPO) telephone cable design - overall longer & wider than standard 10” models - table of supplemental factors on back


TER No.5Cabling

5/5 set for calculating the Transmission Equivalent Resistance for all exchanges in General Post Office (GPO) telephone cable design - overall longer & wider than standard 10” models - table of supplemental factors on back


Tubemaking and Deep DrawingMachining

Extra wide & made for Tube Investments Ltd for drawing sheet metal through a dye to create tubes - various conversion tables & aids on back


U1 Universal ILog-Log

Universal I = Trig scales on stock - tables of conversion factor/densities of metals/densities of non-mtal materiels on back


U1 Universal One Log-Log

Parallel lines logo - tables of conversion factors on back


U1/2 Universal IPocket Log-Log

Tables of conversion factors/densities of metals/densities of non-mtal materiels on back


U2 Universal IILog-Log

Universal II = Trig scales on slide - Trig formulaes on back


Unique Mannheim (type 2) - early

One of the earliest model’s - table of Trig values & formulas on back


UniversalLog-Log

On all Log-Log models LU unconventionally = Log Upper (LL2) & LL = Log Lower (LL3) - incl. CI scale + tables of properties of materials on back


Wilkinson SugarRetail/Conversion

Unusually a slide rule specifically designed for Anglo-American pre-decimal commodity market & incorporating scales for 2 different currencies - table of decimal equivalents of fractions in well of stock


Unknown
ModelTypeCommentsThumbnail
"Consul" The Educated Monkey Replica Child's Teaching Aid/Calculator for simple arithmetic

Replica sold by ARITHMEUM - original Invented & patented (US1188490) by William Robertson in 1916 - “Consul” = name of famous performing monkey of the day - set x & ÷ problems with feet - results framed by monkey’s hands ​(+ & - problems need Addition Table card)​


(NoName)Alcohol Proof

Layout on back merely extends range from front


(NoName)Cheese making - System K. Von Henning

Possibly designed by Dutch poultry farmer & factory owner Karel von Henning (1896-1955) - helped Dutch cheese makers calculate optimum yield of cheese in Kg’s per 100L of milk - read more ... or try out here the online simulation created by Andries de Man


(NoName)Desktop Gunter Rule

Invented by Edmund Gunter (1581-1626) - standard layout for a Gunter i.e. ​Diagonal scale on front face + full-length scales on back


(NoName)Desktop Poly-slide (2) Steel Bars & Sections Weight Calculator - imperial

Wide-bodied model possibly made by BH ​


(NoName)Desktop Steel Weight Calculator - imperial

Wide-bodied & well made but otherwise no clues as to the maker​ - scale layout identical to Robson model


(NoName)Enhanced Mannheim

Japanese maker as JAPAN blind stamped in back of stock but blatant copy of Sterling Plastics, Inc. 589 Senior with red coloured scales on both sides of slide    


(NoName)Gaugung Diagonal Line Rod

½ inch square rod with brass shaven tip used to measure diagonally the approximate content of casks (max 240 gallons) of similar aspect ratios


(NoName)Half Gunter Rule

​Diagonal scale on front face + full-length scales on back but no A scale


(NoName)Hatters Gauge

Probably made in continental Europe + unusually calibrated in metric & imperial - read more … 


(NoName)Lighting

​Probably of Polish origin with table of factors/constants on back


(NoName)Machining Time

German origin + outer scale = cutting speed mm/min, inner scale = diameter & spiral inner scale = main feed time per rev 


1246 Gevaert Separation Control ChartColour Separation

Graphic arts control chart made for Belgium company Gevaert (better known as Agfa-Gevaert) for separating colours & black to white 


1410 PlanisphereDesktop Astronomy - Northern Hemisphere

Slide chart to calculate star positions & star signs but apart from being German & having 1410 as a possible model number on the back, its provenance is a bit of an enigma


Atlas CopcoPocket Pipe Flow - imperial

Specially commissioned by Atlas Copco - a Swedish company suppling industrial compressors, generators, pumps, etc. + table of correction factors for pipe bends on back - see also sibling metric model


Atlas CopcoPocket Pipe Flow - metric

Specially commissioned by Atlas Copco - a Swedish company suppling industrial compressors, generators, pumps, etc. + table of correction factors for pipe bends on back - see also sibling imperial model


Atlas CopcoPocket Pipe Flow for Compressed Air - metric & imperial

Specially commissioned from unknown Japanese maker by Atlas Copco - a Swedish company suppling industrial compressors, generators, pumps, etc. + table of correction factors for pipe bends on back - uncommonly dual metric & imperial calculator (black coloured scales for metric but red coloured scales for imperial)


B.F. GrizzleWater Line Capacity

For calculating the friction loss in a section of pipe & head loss for a given pipe diameter, length & flow - layout based on Hazen–Williams equation - modern adaption of Lawrence-made model but with © renewed 1971


BalkenschuifWooden Floor & Ceiling Beams

Designed by K. Schippers & made by in-house whilst working as building superintendent for Rotterdam city council for calculating size/weight of wooden beams - see also smaller version


BMI CalculatorPocket Dietary

Mechanical calculator to determine (metric or imperial) an individuals  Body Mass Index (BMI) based just on height & weight +  automatically retracting tape measure part manages body fat based on the circumference of the waist. Read more …


Carpenter TimberJoint 2-fold Large Plate-hinged Coggeshall

D Girt line = 4-40 + four-entry ¼ to INCH scale table on front + E & M scales (split over 2 legs) on back


Carpenter TimberPocket Joint 4-fold Old Arched-hinged Coggeshall

D Girt line = 4-40 + 12-24 “Pence per Load” table & eight-entry ¼ to INCH½ scale table (split over 2 legs) on front


Darnley's Rotable Lightning Calculator Child's Multiplication Table Teaching Aid/Pencil Case

Invented & patented (GB167699) as a teaching aid for 1 - 20 multiplication tables by Percy Darnley & Barnett Richards in 1920 - possibly inspired by earlier 1885 German patent (DE33155) of Peter Wiesenmüller - dark-blue & green versions also made + German 4-colour series branded ROKA


DieterleDancing

Slide chart based on registered design for German dance school Kurt und Marga Dieterle showing the basics needed for 8 different ballroom dancing styles + advert for various dancing classes on back


Easy-Keys!Waistcoat Music Chord Indicator & Transposer

Slide chart copyrighted design by American Norton Gross + table chords & chord structure on back


ElectrofloBoiler Efficiency & Energy Costs

© design by H.W. Healy 1923 to optimise efficiency of commercial bopiels ((150-250 lbs/inch) + form & pinned construction suggests OEM rule by L&C Hardtmuth for London-based Electroflo Meters Co.


Ernst Gerber Heating CalculatorHeating requirements for rooms

® design by Ir. Ernest Gerber but clearly values obtained were internationally accepted norms for commercial projects - “bible” for heating industry - many nomograms compliment complex layout ​


Everard4-sided Alcohol Gauging poly-slide(4)

Post 1824 because of Imperial based units/gauge marks + back of slide Face “A” = Divisors for various liquids + back of slide Face “B” = scales for correcting calculations for spheroid casks & other models + back of slide Face “C” = more Divisors + back of slide Face “D” = blank


Flexider BeneluxPipe Expansion poly-slide (2)

Unusual patented design (? made by UK maker Blundell) with windows on both sides of stock revealing scales on 2 non-reversible slides + pictogram explaining formulas on back + Flexider Benelux b.v. was a NL company but is now part of Anamet Europe


Forcing DiscHorticulture

Slide chart designed by Dutchman W. Granneman in 1975 to calculate how to alter/change flowering/harvesting time of tulip bulbs + can also be used for other perennials & other countries with different seasons + issued by Dutch International Flower Bulb Centre - see original by ALRO


HABSChild's Multiplication Table Teaching Aid

German patented (D.R.P.) teaching aid for 1 - 20 multiplication tables - name HABS attributable to the German “Ich habe es” or “I have it” - Spanish “El Calculador” version also known to exist ​


II3-I05-0I-I3Music Guitar Chords

Russian slide chart with revolving wheel for choosing chords


MAGIC - BRAIN CALCULATORSlide Adder - silver/red

Although branded as from Japan possibly made by Hong Kong based Kingson - single adder design for both addition & subtraction​ - many, many similar looking OEM versions sold


Merchants CalculatorRetail

1946 © Sears, Roebuck and Co. dual purpose design: (i) top 3 scales for staple & seasonal requirements & (ii) bottom 4 scales for % mark up, mark on, cost & selling prices + scale groups cannot be used in conjunction


MERK-o-GRAAF MERKENZOEKER Business

Slide chart from defunct Dutch marketing company Van der Graaf & Co. to help compose a trademark or brand name + company slogan = your brand is your silent salesman - read more (in Dutch) ...


MiraccordMusic Guitar

Slide chart for choosing guitar chords


Noel-BentleyDesktop Paper Roll Computor poly-slide (2)

Robert Noel-Bentley design (patent CA489176 - 1952) for calculating (pre-shipment) physical characteristics of commercially manufactured large & heavy rolls of paper - possibly made by Blundell.


Orgelbau-Fachverlag Desktop Music Organ Pipes - System Rensch

Made for specialist German music publisher Orgelbau-Fachverlag for scaling organ pipes (wood metal flues & reeds) but a follow-on cheaper & thinner version of original limited high-quality Laukhuff Orgelpfeifen model by F-C + Table of frequencies on back


Orgelpfeifenmensuren-Rechenstab (ver. 2)Music Organ Pipes

Copyrighted design by Dr. Wolfgang Adelung (1920–1994) using Töpfer's index for scaling organ pipes - Adelung was a well-known German organist who published many books related to building & playing of organs + "simpler" predecessor to limited high-quality Laukhuff Orgelpfeifen model by F-C  


Petit & Fritsen (ver. F)Music Carillons

Specially commissioned slide chart by Dutch bell foundry (still operating) Petit & Fritsen + designed by Hien Fritsen to help carillonneurs choose optimum set-up of bells (tones) for carillons of 1-46 bells + on back a table to calculate strength of housing needed for a given bell weight when being rung - see also GB & NL versions


Petit & Fritsen (ver. GB)Music Carillons

Specially commissioned slide chart by Dutch bell foundry (still operating) Petit & Fritsen + designed by Hien Fritsen to help carillonneurs choose optimum set-up of bells (tones) for carillons of 1-46 bells + on back a table to calculate strength of housing needed for a given bell weight when being rung - see also NL & F versions


Petit & Fritsen (ver. NL)Music Carillons

Specially commissioned slide chart by Dutch bell foundry (still operating) Petit & Fritsen + designed by Hien Fritsen to help carillonneurs choose optimum set-up of bells (tones) for carillons of 1-46 bells + on back a table to calculate strength of housing needed for a given bell weight when being rung - see also GB & F versions


RG-44Demonstration Military Artillery Range Finding - System Grigorovich

Made for NVA 266 & 256 = German Nationale Volksarmee Infantry Division - instruction model for field version of RG-44 ​


Sikkens Blind ColorColour Blending

Slide chart made for Dutch paint company Sikkens (now part of Akzo-Nobel) for ensuring blends/combinations of basic Dutch standard NEN colours are “colour blindness proof”  


Slide Rule of MusicMusic Chord Indicator & Transposer poly-slide(3)

Designed & copyrighted by American musician Henry E. Pendleton


Smarty CatChild's Teaching Aid/Calculator for Simple Arithmetic - early

Based on a 1953 Spanish patent (ES38332) by Cándido - snappy model name ​comes from cat face on both sides of cursor (line-up windows = eyes + mouth) + cat paw mark impressions on ends of stock (front & back) - 1 side for simple arithmetic + other side for multiplication - later version with multi-coloured bands on stock


Smarty Cat/Skole-RegnestokChild's Teaching Aid/Calculator for Simple Arithmetic

Multi-coloured version based on a 1953 Spanish patent (ES38332) by Cándido - snappy model name ​comes from cat face (line-up windows = eyes + mouth) + cat paw mark impressions on ends of stock on the original - 1 side for simple arithmetic + other side for multiplication


Total StralenschutzPocket Radiation

Non-military ABC (Atomic, Biological & Chemical) fallout calculator specially made by possibly NORMA or CONTROLLER for German company: Total KG Foerstner & Co. - see also Nestler made version


TwaddellStrength of liquids

For calculating acidity or sweetness of liquids + slide much longer than stock + see Hezzanith Hydrometer for taking measurements in Twaddell’s - read more ...


VISCALEXPocket Petroleum Pipes

Specially commissioned by Mulhouse-based engineering company Société Alsacienne de Constructions Mecaniques with French patented  design for calculating pressure drop in petroleum/fuel pipes or conduits + company name & table of constants on back 


Viskositaets-Temperature KalkulatorViscosity-Temperature Calculator

Made for German chemical specialities Schwegmann (still in business) but maker unknown + general viscosity calculator for liquids according to various norms e.g. Engler, Gardner-Holdt, etc  


кнп-57Aviation poly-slide(2)

Russian-made flight computer equivalent to classic Dalton designed American E6-B


US Navy Hydrographic Office
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2102-C Rude Star IdentifierDesktop Astronomy - Northern & Southern Hemispheres

Slide chart A-N Type 1 for aeronautical use based on an original design by Gilbert T. Rude but later modified by Elmer Collins + set consists of a double-sided white base plate (side for each hemisphere) & 6 transparent plastic overlays  


Van Oosterhout, A.
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(NoName)Desktop Replica Gunter Rule

Invented by Edmund Gunter (1581-1626) - replica made by KRING member Ton van Oosterhout ​- standard layout for a Gunter i.e. ​Diagonal scale on front face + full-length scales on back


Napier BonesReplica Calculating Rods

Invented by Scot John Napier (1550-1617) replica set made by KRING member Ton van Oosterhoutset consisting of 1 multiplier rod + 10 multiplication table rods + 1 larger squares & cubes rod ​


VEB Fuellhalterfabrik MAKEBA
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Makeba-KombinatorPencil Mannheim

Mechanical drop-lead pencil incorporating a crude slide rule as part of the barrel


VEB MANTISSA
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1731 523/4Wallet Darmstadt

Given quality finish probably special commission by military 


1802Climate, Dew Point & humidity

Made for Feutron Klimasimulation GmbH for calculating with a max atmospheric pressure of 760 Torr


MultiPocket log-log

Company logo top right-hand corner


Véma Drukwerk bv
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Akkoorden-VinderMusic Chords

Slide chart for any instrument for finding 9 most popular chords for 17 different tones + sibling Table D'Accords green version in French also issued 


Venetsianos (Panagiotis)
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Dr. HaroLogarithms of numbers

Concept invented by Dr. Haro, a French army medical officer, & presented to a conference in 1887 but probably never went into production - CD version ingeniously made by Pano


W.H. Harling
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702Desktop Enhanced Mannheim - early

No makers name or logo - catalogued by Colin Barnes as “Lloyds Register Slide Rule” - table of constants on back


Waltman Jr., J.
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BalkenschuifjeLilliput Wooden Floor & Ceiling Beams

Designed by K. Schippers for rapidly calculating size/weight of wooden beam needed to conform to Amsterdam or Rotterdam building regulations - see also larger version


West & Partners, A.
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GliderRietz

Possibly made by John Davis & Son - Glider name from slide-long slotted metal patented (GB232037 - L.E. Edwards) tensioning spring for “automatic” smooth sliding - steel back + paper table of conversion factors


White & Gillespie (W&G)
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432Electro Dualface Comprehensive

Highly innovative thumb-wheel cursor for extra cursor positioning accuracy


476Dualface Trigonometrical/Stadia

Very unusual scale layout incl. Exsec-Versine & Arc-Chord


William Langley
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Carpenter TimberDesktop Coggeshall

Rare duplex Coggeshall with 4–40 GIRT LINE for volumes of round timber + 2 sets of brass gauge pins (marked 0,16, 8 & 8,16, 0 respectfully) for round, 8 or 16 sided timber + INVERTED LINE (AI scale) for volumes of rectangular timber - compared to Dring & Fage version layout front & back reversed


Wizard Werke GmbH
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CALCULATING MACHINESlide Adder - silver/black

Single adder design both addition & subtraction ​


WK-Wohnen
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FarbschieberColour combinations for Interior Designers poly-slide (3)

Developed in cooperation with German Institute for Colour Psychology - all 3 slides & inside top/bottom edges of cursor “tongue and grooved” - all slides interchangeable & reversible - read more ...


Wolters-Noordhoff
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112Technical two-tone

OEM by FUJI + cm on back


1200 (ver. 2)Darmstadt-like two-tone

OEM by FUJI


87Rietz two-tone

OEM by FUJI


FJ 102Technical two-tone

OEM by FUJI + cm scale on back


JE 650Technical two-tone

OEM probably by Faber-Castell as strikingly similar to F-C 52/81