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.

No comments: