• 455 Martinson, Los Angeles
  • 8 (043) 567 - 89 - 30
  • support@email.com
  • Ruxton Multi-Vider drop-lead pencil & slide rule
  • Rare Otis King Model K - white scales on black background
  • Pocket Hexadecimal Slide Adder for Computer Programmers
  • Post 1824 Dring & Fage Alcohol Gauging Rule
  • Darnley’s Rotable Lightning Calculator/Pencil Case
  • Lawrence Antenna (classified by UK & US during WWII) for Radar Beam Pattern Detection
  • Makeba Kombinator pencil & slide rule
  • Rare Carbic-made Fischer Calculator
  • For Calculating Strength of Liquids in Twaddells !!
  • PTT rule for Cable Radio (Signal Loss/dB)
  • Smallest drum (≈ 2.4m) made by LOGA

My collection ....

In 1991, while unpacking a removal box, I came across a long-forgotten slide rule from my schooldays. I was intrigued and soon a mischievous almost schizophrenic idea was born: “What else could a computer man collect but analogue slide rules!”

Slide rules come in all shapes and sizes but most are either:

  • Linear - by far the most common
  • Circular or disc
  • Drum or cylinder
  • Tubular
  • Watch (pocket or wristwatch)

They are hard wearing, do not break when dropped and unlike modern day calculators do not need batteries! Strictly speaking to be a slide rule it must have at least a pair of logarithmic scales and usually a couple of gauge marks. Most items in my collection fit this definition but the odd novel calculating aid and some hybrids have sneaked in!

For slide rule enthusiasts, collectors and users there is an excellent online Reference Manual by the Oughtred Society covering all the basics and much more. For cleaning/restoration tips try Eric Marcotte’s or Tom Dilatush’s webpage.

My speciality is acoustic (they exist!) and oversized desktop slide rules. But I am also attracted to any slide rule that incorporates a quirky or innovative scale and any novel application - e.g. for Church bells. My collection has grown to 2000+ slide rules, 100+ slide charts, 40+ Ready Reckoners, 15+ slide or dial adders and 30-odd mechanical calculating machines/aids. To find specific items of possible interest try one of the adjacent search options.

Every month or so a new batch is added but because of the sheer volume involved it will take many months, if not years, before the entire collection is uploaded! So check out the relevant NEWS item on the HOME page to see what was in the latest batch!

My wish list

Sought after slide rules still missing from the collection:
A.W. Faber-Castell4/92, 8/13, 8/14, 8/15, 8/168 & 51/88
Addiator GmbHOctadat
Albert MartzCursor for pocket System Frank
ALROCobol Analyser, HaTex & Truck Tyres + any large desktop model
Ausschuss fuer Wirtschaftliche Fertigung (AWF)SR703, SR705-709, & SR754
Controller Calculator KG200 R
DARGUE Bros. Ltd / SimplonSub-Ivory SR-1 & SR-4 + Honduras SD10, WR-2A, WR-5 & WR-7
Engineering Instruments Inc.Either circular “vinylite” model
Fearns CalculatorsBarber Shop Harmony Calculator
FowlerNautical, Artillery, Kearns & Mackay
InglisFLASH RECKONER: Pricing, Photographic Exposure, Stock Exchange, Foreign Money, Paper Trades & Health Insurance
IWA15489 Harmonik
L&C Hardtmuth / Classic10" Series III
Lawrence Engineering ServicesS-M (C.V. Ore) & Exposure (MIT)
LOGATF, T150, T300, O2, Terminator & Baumaan lighting
NestlerCursor/runner for 24b (100cm), RP 75, Kreisrechner & Disc-O-Lator
Slide Rule & Scale Engineering Co. (S.R.&S.E.)- any -
Systeem Matthijssen- any -
UniqueNorman, Perfectus, Dial & Junior
Wed. J. Ahrend & Zoon642T, 649, 651, 690, 696, 698, 699 & 701

Search by maker

Search by keyword

Tip: separate keywords (implict AND) by a space or a comma and if needed, limit the search by adding keywords proceeded by a hyphen: e.g.-Faber, -plastic. Phrases in quotes may also be used.

Browse all 1083 slide rules so far loaded from my collection

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Unusual Slide rules for sale or swop (click on model for details)

A.W. Faber-Castell111/22Business
A.W. Faber-Castell111/66 (ver. 1) DEMEGRAPH - System Schirmer
A.W. Faber-Castell2/82Technical/Log-Log
A.W. Faber-Castell2/83Technical/Log-Log long-scale
A.W. Faber-Castell2/83NTechnical/Log-Log long-scale
A.W. Faber-Castell378Electro
A.W. Faber-Castell62/83Pocket Technical/Log-Log long-scale
A.W. Faber-Castell67/74 BASFPocket Pigment-Volume-Concentration
Blundell Brothers/Rules Ltd. (BRL)G.2Enhanced Mannheim without Trig scales
Blundell Brothers/Rules Ltd. (BRL)L.4Log-Log
Dennert & PapeD 2/28Enhanced Mannheim - early
Dennert & PapeS 6/28 (System Rietz)Rietz
Heath & Co.HezzanithNavigational Mannheim
Nestler0137Pocket Electro two-tone
Nestler11Pocket Enhanced Mannheim
Nestler43Reinforced Concrete - System Hoffmann
NORMA-MechanikMekuria 190Business
Wed. J. Ahrend & ZoonELECTRO 15Electro
Wed. J. Ahrend & ZoonHOLLANDIA-REKENSTOKEnhanced Mannheim
William LangleyCarpenter TimberDesktop Coggeshall