New to slide rules? – What is a slide rule? What is a logarithm? How do you use a slide rule? What do all the scales mean?
– Let’s get started !
Returning to the site? New Rules! Vignettes – 23 short articles and stories about slide rules, calculations, and collecting.
A Searchable Table of the entire collection A Data Sheet for each rule Latest Vignette: America’s Earliest Slide Rule
Collection Photos – a chronological look at the slide rule collection Special Groupings – subgroups, such as oldest, youngest, most scales, specialty slide rules, …
Rule Makers – The collection, organized by manufacturers
A Review of the Logarithm Slide Rule Basics Slide Rule Scales References


Welcome! This database-driven web site presents a personal collection of slide rules as well as other useful information about slide rules, their operation and use. Click the arrows (> and <) on each page or use your keyboard’s arrow keys to move between pages. Use the left navigation pane to go directly to a particular chapter or subject.
-Mike Syphers


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The Oughtred Society 18 March 2023 International Slide Rule Museum