98 



KHRONOMETERS. 



Table and Rules for regulating Clocks. 



By the following Table, clocks and watches may 

 be so regulated as to measure tri 



The stars make 366 revolutions from any point 

 of the compass to the same point again, in 365 

 days and one minute ; and therefore they gain a 

 365th of a revolution every twenty-four hours of 

 mean solar time, near enough for regulating any 

 clock or watch. This acceleration is at the rate of 

 3 minutes, 55 seconds, 53 thirds, 59 fourths, in 

 24 hours, or, in the nearest round numbers, 3 

 minutes 56 seconds, by which quantity of time 

 every star comes round sooner than it did on 

 the day before. Therefore, if you mark the pre- 

 cise moment shown by a clock or watch when any 

 star vanishes behind a chimney, or any other 

 object, as seen through a small hole in a thin 

 plate of metal fixed in a window r -shutter j and do 



