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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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You searched for: ac-1. -plastic
MakerModelTypeMaterialCommentsThumbnail
ALRO (All-Round)100 R (AC-1.04a)Rietz - Hmetal/paper

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

ALRO (All-Round)100 R (AC-1.04b)Rietz - earlymetal/paper

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 

ALRO (All-Round)1010 Commercial (AC-1.17)Business long-scalemetal/paper

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

ALRO (All-Round)1010 Commercial (AC-1.18)Business long-scalemetal/paper

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

ALRO (All-Round)200 R (AC-1.05a)Rietzmetal/paper

​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

ALRO (All-Round)200 R (AC-1.05a)Rietz - green finishmetal/paper

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

ALRO (All-Round)200 R (AC-1.05a)Rietz - H earlymetal/paper

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

ALRO (All-Round)200 R (AC-1.05a)Rietz - two-tone paper discsmetal/paper

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

ALRO (All-Round)200 R (AC-1.05b)Rietz - chrome finishmetal/paper

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

ALRO (All-Round)200 R (AC-1.05b)Rietz - copper finishmetal/paper

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

ALRO (All-Round)200 R (AC-1.05b)Rietz - earlymetal/paper

Conversion chart (fractions/decimals) in lid

ALRO (All-Round)200 R (AC-1.05b)Rietz - green paper discsmetal/paper

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

ALRO (All-Round)200 R (AC-1.05b)Rietz - Hmetal/paper

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

ALRO (All-Round)200 R (AC-1.05b)Rietz - H zincmetal/paper

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

ALRO (All-Round)200 R (AC-1.05c)Rietz - no standmetal/paper

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

ALRO (All-Round)300 D (AC-1.08a)Darmstadtmetal/paper

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

ALRO (All-Round)300 D (AC-1.08b)Darmstadt - earlymetal/paper

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

ALRO (All-Round)400 D (AC-1.09)Darmstadtmetal/paper

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

ALRO (All-Round)500 N (AC-1.11)Basicmetal/paper

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

ALRO (All-Round)500 N Vergouts (AC-1.11)Basic metal/paper

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

ALRO (All-Round)600 E (AC-1.19)Electrometal/paper

Rare example of circular Electro type ​

ALRO (All-Round)746 De Muiderkring (AC-1.27) Radio Electronicsmetal/paper

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

ALRO (All-Round)AL-RO (AC-1.01)Basic Retail- prototypemetal/paper

 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 (All-Round)ALRO-PATENT (AC-1.02)Basic Retail - prototypemetal/paper

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 

ALRO (All-Round)BoB3 (AC-1.nn)Reinforced Concrete - System Dusselmetal/paper

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

ALRO (All-Round)Chem (AC-1.23)Chemicalmetal/paper

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 

ALRO (All-Round)DISCABOIS (AC-1.24)Forestry - System Brouhonmetal/paper

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 

ALRO (All-Round)Ha Tex (AC-1.15) Business/Textile - earlymetal/paper

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

ALRO (All-Round)Ha Tex (AC-1.16b) Business/Textile metal/paper

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

ALRO (All-Round)Ha.A2 (AC-1.12)Basic Retailmetal/paper

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)

ALRO (All-Round)Klinische Rekencirkel (AC-1.39)Desktop Medical - System Lipsmetal/paper

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 

ALRO (All-Round)KLM CONVAIR 240 (AC-1.nn)Aviationmetal/paper

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  

ALRO (All-Round)KLM CONVAIR 240 (AC-1.nn)Aviation - prototype metal/paper

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

ALRO (All-Round)KLM Petrol & Oil Tables (AC-1.29)Petroleum/Conversion - earlymetal/paper

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

ALRO (All-Round)KLM Petrol & Oil Tables (AC-1.29)Petroleum/Conversion - prototypemetal/paper

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

ALRO (All-Round)KLM SYST ALRO - System van Roon (AC-1.35)Desktop Aviationmetal/paper

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 

ALRO (All-Round)MILITAIRE REKENSCHIJF (AC-1.32)Military Terrain Analysismetal/paper

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 

ALRO (All-Round)MILITAIRE REKENSCHIJF (AC-1.33)Military Terrain Analysis - monochromemetal/paper

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 

ALRO (All-Round)MILITARY CALCULATOR (AC-1.nn)Military Terrain Analysismetal/paper

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 

ALRO (All-Round)Ned. Octr. Aangevr. (AC-1.03)Rietzmetal/paper

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   

ALRO (All-Round)Roulette (AC-1.nn)Gamblingmetal/paper

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 … 

ALRO (All-Round)SIRKORSKY S-51 (AC-1.nn)Aviation - prototypemetal/paper

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

ALRO (All-Round)Truck Tyre Performance (AC-1.20)Commercial Transportmetal/paper

 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

ALRO (All-Round)WeM (AC-1.nn)Rietzmetal/paper

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

ALRO (All-Round)WeR2 5 (AC-1.07b)Rietzmetal/paper

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