Monday, February 3, 2014

Ciceri-Smith's Micrometer 1920





From Sell's National Directory of Large Commercial Houses and Buyers' Guide.  London:  Business Dictionaries Ltd., 1920.

Perhaps the first digital micrometer.  Ciceri Smith was from Edinburgh, Scotland and in the wire mesh business, so he made a micrometer to make it easier for employees to gauge wire thickness. The device was apparently accurate to .0001 inches!  He took out a U.S. Patent (No. 495,379) in 1893.  Apparently, Brown & Sharpe bought the U.S. rights.  Surviving examples of these devices change hands for big money nowadays.

For more information, and pics of the real thing, visit the Practical Machinist.

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