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When the latest PC/tablet is out-of-date in 6 months it may come as a surprise that the Englishman in the image, the Rev.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

Controller Calculator KG, (NoName), Waistcoat - early, C, Other, metal

Tech Papers

What is it ?

Skid Stick No. 61

news - So far 809 rules are loaded from my collection

news
01 July 2019

LATEST ADDITIONS – German CONTROLLER

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.

27 May 2019

SAD NEWS

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.

15 February 2019

IM2019 NEWS

The 25th International Collectors Meeting will be held in Scheveningen, The Netherlands. ​Check out the Information Sheet for all the details and complete the Form to register.

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.

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 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-Castell4/60, 4/92, 8/13, 8/14, 8/15 & 8/168
Addiator GmbHOctadat
AlroCobol Analyser, HaTex & Truck Tyres
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 & 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 24b (100cm), RP 75, Kreisrechner & Disc-O-Lator
Slide Rule & Scale Engineering Co. (S.E.&S.E.)- any -
UniqueNorman, Perfectus, Dial & Junior