XI. TIME. . 125 



471. Models (ten) of Compensation Balances, showing 

 various attempts to overcome what is known as the " Error " of the 

 ordinary Compensation Balance, by the late Thomas Hewitt. 



The British Horological Institute. 



472. Marine Chronometer by Earnshaw. 



The British Horological Institute. 



473. Marine Chronometer with Mudge's Escapement. 



The British Horological Institute. 



474. Grossmann's Micrometer. 



The British Horological Institute. 



475. Model of " Ferguson's Paradox." 



The British Horological Institute. 



476. Model of Cole's Resilient Escapement. 



The British Horological Institute. 



477. Callipering Engine, by the late Richard Roberts. 



The British Horological Institute. 



478. Models of English and French Repeating Motions 

 for Watches. The British Horological Institute. 



479. Watch Movement. 



The British Horological Institute. 



480. Marine Chronometer Movement. 



The British Horological Institute. 



481. Collection of Watch and Chronometer Balance 

 Springs. The British Horological Institute. 



482. Map showing allowance of time to be made for velocity 

 of sound as applied to the Westminster Clock Bell. 



The British Horological Institute. 



482a. Working Model, for educational purposes, of 

 a Chronometer Escapement, with a 6-inch compensation 

 balance. Ignaz Herrmann. 



482b. Working Model, for educational purposes, of 

 a Lever Watch Escapement. Ignaz Herrmann. 



Working Model, for educational purposes, of a Hori- 

 zontal Watch Escapement. Ignaz Herrmann. 



Model for demonstrating the law of the compensation balance 

 or of any vibrating or rotating body. Ignaz Herrmann. 



An arm carrying movable weights revolves about a vertical axis under the 

 action of a spring. The time taken for the spring to run down is propor- 

 tional to the square root of the distance of the weights from the axis. 



