This non-commercial website was a 60th birthday present from Ros. The name stems from another family member - our daughter Siân. As a teenager 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When the latest PC/tablet is out-of-date in 6 months it may come as a surprise that the Englishman in the image, the Rev.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.
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.
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. Afterwards try doing a few trial 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/Oughtred Society’s ”Beginner’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. If you are just looking for reference books on slide rules try one of these: MyList 1 or MyList 2 .
In the 1970s Munich based Controller-Calculator KG marketed a series of “Schnellrechners” or fast calculators. Distinctively all the models in the series were circular & made from aluminium - the diameter was also the model number.
The world of collecting has recently lost two world renowned experts & compilers of two of the most legendary collections. American collector Bob Otnes (1932-2019) passed away in April and in May Swiss collector Heinz Joss (1929-2019) passed away. They will both be sorely missed.
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.
In memory of long-scale expert Ed Chamberlain (†18-10-2017) fellow collector Otto van Poelje has reissued his out of print private 2013 publication: “LONG-SCALE SLIDE RULES in LIFE-SIZE IMAGES”
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||4/60, 4/92, 8/13, 8/14, 8/15 & 8/168|
|Alro||Cobol Analyser, HaTex & Truck Tyres|
|Controller Calculator KG||200 R|
|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|
|Graphoplex||6245 & 6250|
|Inglis||FLASH: Pricing, Photographic Exposure, Stock Exchange, Foreign Money, Paper Trades & Health Insurance|
|L&C Hardtmuth / Classic||10" Series III|
|Lawrence Engineering Services||S-M (C.V. Ore) & Exposure (MIT)|
|Nestler||Cursor/runner for 24b (100cm), RP 75, Kreisrechner & Disc-O-Lator|
|Slide Rule & Scale Engineering Co. (S.E.&S.E.)||- any -|
|Unique||Norman, Perfectus, Dial & Junior|