• 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

A man must have a hobby….

hobby

This non-commercial website was a novel 60th birthday present from Ros. But the site name is thanks to another family member - our daughter Siân. When asked as a teenager what I did, she often told her friends: “My Dad? Oh, he collects expensive sticks of wood!”

When the latest PC/tablet is out-of-date in 6 months it may come as a surprise that the Englishman in the image, the Rev. William Oughtred (1575-1660), invented a calculator around 1621 that would be in continual daily use for nigh on the next 400 years. My hobby is collecting and writing about this analogue calculating wonder - the SLIDE RULE. The analogue concept behind the slide rule was successfully adopted and adapted by many trades and professions. Being able to use one is still a licensing condition private and commercial pilots have to meet.

This site is a virtual “display cabinet” for my collection (as it gets uploaded) of slide rules and the odd mechanical calculating aid plus a “bookshelf” for my published articles - enjoy browsing.

The history - how it all began ....

history

To learn more about the history of this calculating wonder check out the “Slide Rule History” by the Oughtred Society (OS) or my 2-page summary (in Dutch!).

Anyone needing a “memory jogger” or is just intrigued how such analogue calculators of the past worked, the International Slide Rule Museum has a richly illustrated “How To Use The Slide Rule” teach yourself course or download a self-running introduction course with synchronised audio I digitalised. Afterwards try out some test calculations with Derek Ross’ online simulation of a Pickett N909-ES slide rule. If all this gets you thinking about starting your own collection then the UKSRC/OSBeginner’s Guide to Collecting Slide Rules” can be a great help.

For any educators looking for maths related inspiration & teaching aids/material then you need to look no further than Nicola Marras’ website. But if you are just looking for reference books/publications on slide rules try one of these: List 1 or List 2.

Latest additions

newadd

Slide Rules

COX & STEVENS Aircraft Corp., V (M.L. Navigatie-Doos), Navigational Boxed, L, Duplex, metal/plastic

Tech Papers

A Cheesy Tale

Gazette Issue 20

news - So far 1125 rules are loaded from my collection

news
08 December 2020

F-C BOOK GOES ONLINE

Premièred at the December 6th UKSRC Zoom meeting the popular book by Peter Holland on the slide rules made by A.W. Faber and A.W. Faber-Castell has gone digital. The 8th Edition is now free to download from here …

27 November 2020

LATEST ADDITIONS – AHREND rules

Started as a family business in 1896 by Dutchman Jacobus Ahrend, the company (still operating) became an international office supplier and was granted a Dutch royal warrant – hence the crown in their logo. Slide rules featured prominently in their catalogues. However, they were only a reseller of OEM models. Check out all my AHREND branded items here ...

14 September 2020

NEW BUMPER EDITION

This year’s bumper and attractively priced edition of the UKSRC’s Gazette Issue 20 is now available. Ordering (payment via PayPal) could not be simpler via the UKSRC subscription ordering webpage.

01 August 2020

MAGICAL SLIDE RULES

Did you know a special model exists for each house of Hogwarts School of Witchcraft & Wizardry? Depending on your Gryffindor, Ravenclaw, Hufflepuff or Slytherin affiliations select your Harry Potter inspired sorcerous slide rule simulation from Robert Wolf’s website ...

24 May 2020

1000th CALCULATING AID UPLOADED!

A milestone I expected to reach earlier. It takes ages to catalogue & capture conscientiously all the details. The upside is that I am learning a lot about my collection! The1000th entry was fittingly an unusual & extremely rare KLOOS disc for heavy-duty steel constructions

13 May 2020

STOP PRESS: new book

As a labour of love ALRO expert Otto van Poelje published: The ALRO Catalogue. The Dutch maker is famous for circular models where the lid doubles as a desk stand. In 200+ page hardback book every calculating disc, slide rule & slide chart ever made by ALRO is meticulously catalogued & photographed. Attractively priced at Euro 35 (excl. P&P) order your copy online here ...

01 October 2019

IMPOSIBLE is POSSIBLE!

Generically a slide rule can solve complex calculations but CANNOT do simple arithmetic. A rare and unusual exception is the newest addition to the collection - a System Korte slide rule that CAN add and subtract!

09 May 2018

Amazing Digital Slide Rule

Ace Hoffman has developed an awesome simulation of a linear, round, concentric and drum slide rule. From Ace’s Homepage download a function-rich version for your phone, tablet or desktop.

02 February 2017

TOP SECRET !!

Lawrence made the only known slide rule considered so vital to the WWII effort that the UK & US governments had it classified - based on research from MIT it calculated radar antenna beam patterns, beam width, gain, etc.

My wish list

wishlist
Sought after slide rules still missing from the collection:
MakerModel(s)
A.W. Faber-Castell4/92, 8/13, 8/14, 8/15 & 51/88
Addiator GmbHOctadat
AHREND (Wed. J. Ahrend & Zoon)642T, 649, 651, 690, 696, 698, 699 & 701
Albert MartzCursor for pocket System Frank
ALRO (All-Round)Cobol Analyser, HaTex, Truck Tyres & ST 9 + any large desktop
AWF (Ausschuss fuer Wirtschaftliche Fertigung)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
Graphoplex6245
Inglisany FLASH RECKONER
ITAB (Internationaler Tabellenverlag)Multicalor Flachheizkorper & Styropor-Vollwarmeschutz
IWA – F. Riehle GmbH & Co KG15489 Harmonik
Johann Faber180/080, 180/082, 9203, 9204 & 9204
Keuffel & Esser (K&E)4081-3 Braille version
L&C Hardtmuth / Classic10" Series III
Lawrence Engineering ServicesS-M (C.V. Ore) & Exposure (MIT)
LOGATF, T150, T300, O2, Terminator & Baumaan lighting
LOGAREX27705
LOGOMAT1300/1303
NestlerCursor/runner for 24b (100cm), RP 75, Kreisrechner & Disc-O-Lator
S.R.&S.E. (Slide Rule & Scale Eng. Co.)- any -
Systeem Matthijssen- any -
UniqueNorman, Perfectus, Dial & Junior