VINTAGE-KEUFFEL & ESSER Polyphase SLIDE RULE 4093-3S, Leather CASE & box. PreWW2

This pre WW2 Keuffel & Esser, New York, USA. Polyphase Slide Rule 4093-3S This particular slide rule comes with a leather case and a box for storage. It is an amazing collector's item for anyone interested in engineering and science.

The tool itself is like new. Very nice slide rule, come with worn outer box. And leather case in good condition. Case has name written inside of previous owner see pic and date Probably from the 40s.

This one is unusual because it has the original box. This is a museum piece.

It also has mahogany wooden it. The person who had it before wrote the date 1/26/29 inside it which means this is a PRE WW2 piece. There was a time when engineers and students relied on slide rules to make their calculations.