• 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 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When the latest PC/tablet is out-of-date in 6 months it may come as a surprise that the Englishman in the image, the Rev.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.

The history - how it all began ....

history

To learn more about the history of this remarkable calculating wonder check out the “Slide Rule History” by the Oughtred Society 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. 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 .

Latest additions

newadd

Slide Rules

Baird & Tatlock, Richmond's Improved, Milk, L, Closed/solid frame, wood

news - So far 773 rules are loaded from my collection

news
01 October 2018

LATEST ADDITIONS – Differentials

As part of their P.I.C. & British Thornton ranges THORNTON made a series of models with patented direct & inverse differential trig scalessee here. Such scales offer greater accuracy than is possible with traditional trig scales.

09 May 2018

Amazing Digital Slide Rule

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

03 April 2018

We’ve MOVED!

Well the website has. Service from the old provider went downhill. So I have switched to a premium webhoster with extra security.

Please let me know if you spot anything not working.

10 January 2018

New Long-Scale EBook

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

02 February 2017

TOP SECRET !!

Lawrence made the only known slide rule conceived 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-Castell4/60, 4/92, 8/13, 8/14, 8/15 & 8/168
Addiator GmbHOctadat
AlroCobol Analyser, Ha Tex & Truck Tyres
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, 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 a 342 (50cm) & for a 24b (100cm)
Slide Rule & Scale Engineering Co. (S.E.&S.E.)- any -
UniqueNorman, Perfectus, Dial & Junior