decimal micrometer

Made:
1857
modifier:
Joseph Whitworth and Company Limited

James Cocker's patent decimal gauge (micrometer), and wooden box, unmarked, United Kingdom, 1857

Patented by James Cocker in 1857, this decimal gauge micrometer did not rely on a micrometer screw. It was modified by Messrs. Joseph Whitworth and Co., to measure from zero to two inches with a scale graduated in thousandths of an inch.

Details

Category:
Industrial Metrology
Object Number:
1931-328
Materials:
brass (copper, zinc alloy), cast iron and steel (metal)
type:
micrometer
taxonomy:
  • furnishing and equipment
  • measuring device - instrument
credit:
British Railways Board Records Office; London Midland & Scottish Railway Co.