l68 APPENDIX. 



pendulum had gained one whole minute^ together with the 

 fifteen feconds determined by the pendulum and the revo- 

 lution of the fun : and although it appears by the 

 eleventh column of the foregoing table that the watch did 

 not lofe uniformly at the rate of four feconds in twenty- 

 four hours, yet its mean rate leaves as little doubt with 

 regard to the whole fninute gained by the pendulum, as if 

 its going had been perfectly uniform during the whole 

 time. For, if from the fum of all the periods in the 

 fecond column, and of all the accelerations in the tenth, a 

 mean rate be taken, it makes the acceleration of the pen- 

 . dulum on the watch to be 80", 7 9 in twenty- four hours, 

 which differs from the acceleration obferved by the revo- 

 lution of the fun only 5^,75; and from the rate of going 

 of the watch, determined by the revolution of the fun, 

 only i'',79 : hence there can be no poflible room to 

 fuppofe an error of a whole minute. 



Although the period of twenty-four hours, and the 

 rate of going of the watch for that time, are very accu- 

 rately determined by the revolution of the fun; it may 

 not be improper here to take notice, that from a mean of 

 fix altitudes of the fun, taken by a very good agrono- 

 mical quadrant of eighteen inches radius, the watch was 

 computed to have loft 5"^^, in twenty-four hours, which 

 differs from the rate given by the revolution of the fun 

 only \"l. \ this may ferve to {hew how far the mean of 

 a great number of obfervatlons by the fame obferver and 

 3. inftrument 



