APPENDIX. 



It appears by the original obfervations that the pendu- 

 lum began its vibrations at 60", the inflant in which the 

 lirft hmb of the fun was obferved to touch the fide of the 

 vertical wire in the telefcope of the Equatorial, that 

 is, at five hours, nineteen minutes, twenty-eight feconds 

 in the afternoon by the watch, on the i6rh of July ; and 

 by every comparlfon of the pendulum with the watch, 

 that the pendulum was conftantly gaining on the watch, 

 and in a period of twenty-four hours, four minutes, 

 forty-one feconds, had gained on the watch feventy- 

 nine feconds j and when the revolution of the fun was 

 completed, it appeared, that the watch had loft four 

 feconds in the exadl period of twenty-four hours ; there- 

 fore, if four feconds loft by the watch, be fubtra(9:ed from 

 feventy-nine, the time gained by the pendulum on the 

 watch, it will leave feventy-five feconds for the time 

 gained by the pendulum on the mean^ or true time, no 

 dedudion being here made for the contraction of the pen- 

 dulum-rod by the cold. 



The odd fifteen feconds are determined by obferving, 

 that the pendulum fhewed four feconds and a half exadlly 

 when the fun had again returned to the vertical wire ; fo 

 that this period is determined wholly by the fun, and 

 totally independent of the watch ; but as the watch is 

 found by the fame obfervation to have loft only four 

 feconds, recourfe is had to the intermediate comparifons 

 of it with the pendulum, which clearly {how that the 



C c pendulum 



167 



