James Cocker's patent decimal gauge (micrometer) from his original patent of 1857 no. 1680
earliest 1857
decimal micrometer
- Made:
- 1857 in United Kingdom
- 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), steel (metal) and cast iron
- Measurements:
-
10 x 14 x 25 cm
- type:
- micrometer
- credit:
- British Railways Board Records Office; London Midland & Scottish Railway Co.
