Engineer's combination rule

Made:
1870
maker:
Joshua Routledge

Engineer's combination rule, c. 1870 includes protractor, depth gauge, rule and slide rule function. This combination rule includes a protractor on the jointed hinge and a brass depth gauge sliding section and a sliding logarithmic scale which could be used as a slide rule type calculator.

Details

Category:
Industrial Metrology
Object Number:
1984-414
Measurements:
overall: .1575 x 4.9213 x 1.6535 in.; .4 x 12.5 x 4.2 cm
type:
combination rule and depth gauge
credit:
Wickham, H.W.