Description
Arched foot with central index surmounted by vertical rule (scale of inches 1-9½). The upper section of the rule is demountable and fixed by a spring clip. The sliding sight has a fixing screw.
Acknowledgement: © History of Science Museum, University of Oxford, inv.41377
Arched foot with central index surmounted by vertical rule (scale of inches 1-9½). The upper section of the rule is demountable and fixed by a spring clip. The sliding sight has a fixing screw.