The Most Important Instrument: Slide Rules and the Making of the Modern World

There was a time however, when either you knew how to use it or you didn’t. If you did, you could make things bigger, faster, stronger. You could make things that had never existed before. Look around you. If the things you see (and many you don't) were designed before the mid-1970s, then it is almost guaranteed someone used a slide rule to design them. Simply put, the slide rule is one of the most important technological instruments of the 20th century that has never been studied, written about or presented in any significant manner to a general audience.

For the first time, the MIT Museum will put on exhibition the Keuffel & Esser Company Slide Rule Collection, one of the world's finest, encompassing everything from the Beatley I-Q rule (used by New York City school psychologists) and braille rule (used by an engineer who lost his sight in World War II) to the most classic engineering rules of all time. You don't have to know a single thing about trigonometry or calculus to appreciate the ingenious design of these instruments, and how important they have been to history. And of course, if you do know a thing or two about how to use a slide rule, we imagine you will still be surprised and fascinated by the variety and purposes of the slide rules on display.

Credits: The MIT Museum gratefully acknowledges the family and friends of Alfred E. Busch for their generous donations in support of this exhibition. Additional support has been provided by The Oughtred Society, which is dedicated to the preservation and history of slide rules and other calculating instruments.

Learn more:

• The Oughtred Society, for everything slide rule
• How to calculate with a slide rule
• Keuffel and Esser Slide Rule Collection Donated to MIT Museum 2005