Keywords: Early Chronometer Balance Wheels.png Drawings of temperature-compensated marine chronometer balance wheels These were designed during the 1st half of the 19th century by British chronometer makers attempting to improve on the standard Earnshaw balance and win prizes at the British Admiralty Chronometer Trials These are all attempts at solving the 'middle temperature problem' An Earnshaw balance when adjusted to keep time at high and low temperatures gains as much as 4 seconds/day at middle temperatures from nonlinearity The one on the right actually uses a tube of mercury for compensation From Glasgow David 1885 Watch and Clock Making Cassell Co p 247-256 Chronomètres de marine à température compensée Downloaded from http //books google com/books id 9wUFAAAAQAAJ pg PA252 David Glasgow 1885 Watch and Clock Making Cassell Co New York p 247-256 on Google Books 1885 David Glasgow Public Domain - author died more than 70 years ago <br /> PD-old PD-old Balance wheels Chronometer Old horology prints Cassell Co |