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When the latest PC/tablet is out-of-date inside 6 months, it may come as a surprise that the Englishman in the image, the Rev.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

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 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.