All my items are hand picked, checked, cleaned and described to my best knowledge after serious research. I do not waste time on uninteresting pieces. You won’t find stupid flaws like crack and parts missing. Condition will be described in detail and shown in pictures. Feel free to roam around and if you have any questions or concerns, just send me a short message. Do keep in mind that most items are pretty unique and I do not often come across the same item twice.

What is a slide Rule?

A slide rule is a mechanical calculating device that was handled by hand or laid flat on a desk. It has a stationary (outer) part and a sliding (central) part, both marked with logarithmic scales. In most cases values are chosen en read with the help of a moving see-through curser with one or more focus hairlines. There are scales for easy and complex calculations. More scales give more possibilities for different calculation. The slide rule was the predecessor of the electronic calculator and used for over 4 centuries.

What does a slide rule look like?

A slide rule is an often ruler shaped, far wider than high, but it can also have a circular shape in order to allow for longer scales which offer more accuracy. Slide rules can come in many sizes, forms and materials. Though the basic color is often white for easy reading, they can also have different colors. Slide rules can be generic for mathematical use in school or can be manufacture for a certain profession with only very dedicated calculations. It can be one sided or double sided, allowing for more scales.

Interesting slide rule brands from Europe

From the many slide rule manufacturers around the world there are a few very well known ones in Europe, which you can find on this website.

Alro: A small brand from Holland in the city of The Hague, specializing in round slide rules in metal cases. Their model 200R sold the most and was mandatory in schools in Holland in the 1950’s. Here you find an article about this Alro slide rules from Holland.

Faber-Castell: From Germany, a name associated with all kinds of drawing equipment made many different slide rules over the years and is still in business today. Their most famous model is the 2/83N which is often called the best in the world. You find it in the article World famous slide rules

Nestler: or Albert Nestler. A brand from Germany that made many different models and were in business until the end of the slide rule era. Their most famous rule must be the 23 Rietz model that was the favorite of many scientists including Einstein.

Graphoplex: a brand from France, also known for their writing and drawing materials and still in business today. Their best know model would be the model 1600 which was also used at many schools.

Slide rule brands from around the world

Beside the brands above, you can find slide rules branded Ahrend (the Netherlands), Aristo Dennert & Pape (Germany), Blundel Harding BRL (United Kingdom), British Thornton (United Kingdom), Flying Fish (Japan), Fuji (Japan), IWA (Germany), Keuffel & Esser (USA), Logomat (Germany), Otis King (United Kingdom), Pickett (USA), Royal (Japan), Reiss (Germany), Sun Hemmi Post (Japan) and various other small brands.