Propeller Pitchometer, J Nicolson Edinburgh.
Propeller Pitchometer Patent No 11210 J Nicolson Edinburgh, Optician Edinburgh in original case.
Ships pitch as well as roll, but this J. Nicolson optician propellor ‘Pitchometer’ is instead for determining the pitch of a boat’s propeller – how aggressively the lead edge of the prop blades grab at the water. The heavily built brass gauge has a small spirit level behind the tightening wheel, and adjusting arms to conform to the complex geometry of the propeller being measured. Unfortunately, the user manual is missing.Â Scotland C 1900 and the leather hinged is broken. Dimension case 47,5 x 6 x 4 cm.