拍品專文
it appears that by sub-dividing the travel of the pendulum in this way, the neccessary travel of the arm is approximately halved.
細節
An unusual early 19th Century brass clinometer
with weighted "pendulum" indicator sub-divided to interact with a secondary "pendulum", the scale divided from 0-30 for port and starboard -- 20in. (51cm.)
See illustration
with weighted "pendulum" indicator sub-divided to interact with a secondary "pendulum", the scale divided from 0-30 for port and starboard -- 20in. (51cm.)
See illustration