An Optical Gear Tooth Micrometer

Published in Spring 1997  Zeiss Historica Journal

Author: Nicholas Grossman

See Page 8 – 9.

The author profiles one of the many mechanical tools developed to aid manufacturing in early 20th Century factories: The Optical Gear Tooth Micrometer.

To go to the Journal itself, click on the year 1997 in the first line above.