Slide Rules

About Vintage Slide Rules

The slide rule, invented by William Oughtred in 1622, consists of two divided scales, one fixed and one movable, and a sliding window called a cursor. Slide rules were the primary tool for performing multiplication, division and other scientific functions up through the 1960s and the development of the electronic calculator.

There are straight, circular and cylindrical slide rules, all collectible. Major manufacturers included Keuffel and Esser, Pickett, Gilson, Dietzgen, Post (which became Teledyne), Faber-Castell, Aristo, and others. Early slide rules were made of wood and celluloid, while later ones tended to be plastic or metal.

The rarest slide rules are 19th Century hand-engraved instruments such as Palmers Computing Scale (a circular model), first published in 1843, or the cylindrical ‘Thacher’s Patent Calculating Instrument’ slide rules produced by Keuffel and Esser Co in the 1880s. These can run close to $1,000 in good condition.

Whatever you do, be sure any slide rule you buy is fully intact and working, as finding replacement parts for a specific model (especially the cursor) can be next to impossible.

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Interviews & Articles

An Interview With Vintage Slide Rule Collector Mike Konshak

An Interview With Vintage Slide Rule Collector Mike Konshak

I’m 61 now, and I’m an engineer. I was thinking if I ever wanted to collect something, I would probably c…  [more]



Best of the Web (“Hall of Fame”)

Slide Rule Museum

Slide Rule Museum

Mike Konshak's amazing antique slide rule reference site 'dedicated to students and engineers of the past and prese…  [more]


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Top eBay Auctions    (get weekly Slide Rules email)

Status       Display       How this works
7 Foot Classroom Slide Rule $99.00 Ends Saturday 1 bid
Aristo 0968 Studio Slide Rule, New $18.13 Ends Saturday 3 bids
Vintage 1944 Slide Rule Manual Keuffel Esser $15.50 Ended 2 mins ago 9 bids
Circular Slide Rule $8.25 Ends Sunday 2 bids

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See also

Tools