• 455 Martinson, Los Angeles
  • 8 (043) 567 - 89 - 30
  • support@email.com
  • 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 disk
  • 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. Most items in my collection fit this definition but the odd novel calculating aid + some hybrids can also be found.

For cleaning/restoration tips try Eric Marcotte’s or Tom Dilatush’s webpage.

My special niche interest is acoustic (they exist!) and oversized desktop slide rules. But I am also attracted to any model with a quirky or innovative scale. 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, many months before the entire collection is uploaded! Monitor 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-Castell4/60, 4/92, 8/13, 8/14, 8/15 & 8/168
Addiator GmbHOctadat
AlroCobol Analyser, Ha Tex & Truck Tyres
Blundell Harling Ltd. (BH)P4463 Holophane Illuminance Calculator
Dargue Brothers Ltd / SimplonSD10 Duplex & any WRn model + Sub-Ivory SR-1/3/4/6
Engineering Instruments Inc.Either circular “vinylite” model
Fearns CalculatorsBarber Shop Harmony Calculator
FowlerNautical, Twelve-Ten, Kearns & Mackay
Graphoplex6245 & 6250
InglisFLASH: 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)
NestlerCursor (runner) for 342 (50cm) & 24b (100cm)
Slide Rule and Scale Engineering Co.- any -
UniqueNorman, Perfectus, Dial, Pioneer Long Scale & Junior

Search by maker

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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 754 slide rules so far loaded from my collection

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Unusual Slide rules for sale or swop

Aristo 939Reinforced Concrete - System Göttsch
Blundell Brothers/Rules Ltd. (BRL) E.3Electro
Graphoplex 1614Demonstration School Log-Log
Hemmi 30Lilliput Enhannced Mannheim
J. A. Nicholl & Co. Mark VI Desktop Artillery for Indirect Fire
Nestler 0440Polymath Reinforced Concrete - System Maarschalk
Rijnja, P. Beams - basicPocket Wooden Floor & Ceiling beams - System Van Gerven
William Langley Carpenter TimberDesktop Coggeshall