The slide rule, also known colloquially (in the US) as a slipstick, is a mechanical analog computer
ThinkGeek Resurrects Slide Rule, Breathes Life Into Dead Technology For No Reason Whatsoever
Slide rule. As a mechanical engineer he always had one close by.
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1945 Juvenia 'Arithmo' Slide Rule Watch
Slide-rule widow - why you should persuade your engineer husband to apply for a job at Boeing!
a slide rule collection! #collections
Pickett metal rules have their partisans. Some consider them an abomination. The company made a big deal about how a Pickett slide rule went to the moon. (To which one geek responded: "Yeah, but a Keuffel & Esser rule built the bomb.")