of the Cambridge Observatory. 



165 



Means of comparisons made at Cambridge by Professor Airy, 



Oct. 22, 15\ 



Means of comparisons made at Greenwich by Mr. Sheepshanks, 



Oct. 23, 3^ 



Assuming any chronometer and the Greenwich clock to have 

 gone uniformly between two comparisons at Greenwich, a simple 

 proportion would give the time shewn by the Greenwich clock 

 at the instant at which that chronometer was compared with the 



