This non-commercial website was an amazing 60th birthday present from Ros. But the website 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When the latest PC/tablet is out-of-date inside 6 months, it may come as a surprise that the Englishman in the image, the Rev.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. Remarkably being able to use such an elegant analogue instrument from a bygone age is still a licensing condition for all private and commercial pilots.
This site is a virtual “display cabinet” for my collection (as it gets uploaded) of slide rules, slide charts and the odd mechanical calculating aid plus a “bookshelf” for my published articles - enjoy browsing.
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 35mm “diafilm” Introduction Course with synchronised audio I digitalised. Afterwards try out some test calculations with Robert Wolf's online simulation of the classic Nestler 23R wooden slide rule. If all this gets you thinking about starting your own collection then the UKSRC/OS “Beginner’s Guide to Collecting Slide Rules” is a must read.
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.
Today I uploaded the 1215th item from my collection – a Magna Carta style milestone I expected to hit earlier. It takes an age to catalogue the details for each item but the upside is that I am learning a lot about my collection! The milestone entry was fittingly an extremely rare & unusual Desktop model from Dutch maker ALRO for the Dutch airline KLM.
Two new catalogue lists have been added to Rod Lovett’s Major Makers search facility. So if looking for details of a model made by ALRO or UNIQUE look them up HERE …
After going digital 15 months ago and over 1,000 free downloads it was time for an update. Edition V 8.1 of Peter Holland’s definitive book (in English and German) on every slide rule made by A.W. Faber and A.W. Faber-Castell is now free to download from here ….
Rod Lovett’s latest facility makes the data compiled on Electro types over many years by Bob Adams easy to search. Use it to find all known specialist Electro and Electronic slide rules – try it out here …
HEMMI with its sunburst logo is a highly respected Japanese maker of slide rules. The company has a rich history – operating from 1895-1975. HEMMI chose to make most of their models from bamboo with celluloid veneers. An understandable choice as bamboo was better suited to the humid conditions of their “home market”: Asia. They sold an impressive range of models - many with usual scale layouts. Click HERE to see the ones I have – including two models that each need 4 cursors to work!
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 ...
ALRO expert Otto van Poelje has published: The ALRO Catalogue. This Dutch maker is famous for circular models where the lid doubles as a desk stand. The 200+ page hardback book has every calculating disc, slide rule & slide chart they ever made - all meticulously catalogued & photographed. Attractively priced at Euro 35 order your copy online HERE ...
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!
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.
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.
|A.W. Faber-Castell||8/13, 8/14, 8/15 & 51/88|
|AHREND (Wed. J. Ahrend & Zoon)||642T, 649, 651, 690, 696, 698, 699 & 701|
|Albert Martz||Cursor for pocket System Frank|
|AWF (Ausschuss fuer Wirtschaftliche Fertigung)||SR703, SR705-709, & SR754|
|DARGUE Bros. Ltd. / Simplon||Sub-Ivory SR-1 & SR-4 + Honduras SD10, WR-2A, WR-5 & WR-7|
|Engineering Instruments Inc.||Either circular “vinylite” model|
|Fearns Calculators||Barber Shop Harmony Calculator|
|Fowler||Nautical, Artillery, Kearns & Mackay|
|Inglis||any FLASH RECKONER|
|ITAB (Internationaler Tabellenverlag)||Multicalor Flachheizkorper & Styropor-Vollwarmeschutz|
|IWA – F. Riehle GmbH & Co KG||15489 Harmonik|
|Johann Faber||180/080, 180/082, 9203, 9204 & 9204|
|Keuffel & Esser (K&E)||4081-3 Braille version|
|KOSMOS||Book: "De Rekenliniaal" - 11th & 12th Editions|
|L&C Hardtmuth / Classic||10" Series III|
|Lawrence Engineering Services||S-M (C.V. Ore) & Exposure (MIT)|
|LOGA||TF, T150, T300, O2, Terminator & Baumaan lighting|
|Nestler||Cursor/runner for 24b (100cm), RP 75, Kreisrechner & Disc-O-Lator|
|S.R.&S.E. (Slide Rule & Scale Eng. Co.)||- any -|
|Systeem Matthijssen||- any -|
|Unique||Junior, Study 500/700/900 & J180/181/182|