9M' ' ^ ACCOFNT OF EXPERIMENTS 



17, On the ninth ©f Deceraber, at noon, I veriSed my divisions,, and 

 found that the scale had sustained no alterations, I let off the pendulum 

 describing arcs of 3 inches and ^, and after accounting for the rate of the 

 clock j*^*^) the mean time elapsed was 16 minutes, S9 seconds f§^ parts. 

 There were exactly 1000 oscillations of the pendulum of experiment, 



18. At the beg'inning I had measured the pendulum „„..S9,694 



At ending it was =..-..... . = = ....,.....„. .3-9,705 



Mean length of pendulum .. = = ....„„....,.. . .39,6995 



19, It described, at the beginning, arcs of 3^ inches, and at ending 1^5 

 hence, it described, on a mean, arcs of 2^ inches, which were equal tO' 

 those described by the clock pendulum. The thermometer was, at begin- 

 ning and ending, 81^. the external air was carefully excluded during the 

 experiment, 



20. For the reasons given in par. 3d, I shall dispense with detailing. 

 the particulars of the other experiments, and merely state here, at one 

 view, the different mean lengths of the pendulum, as it was measured 

 before and after the observations. 



p. 21. By, the annexed table, it will be found, 

 that the medium length of the pendulum, at 

 these different measurements, was a feet 3,698.1 

 inches : and as an equal number of vibrations, 

 both of the clock pendulum, and that of expe- f 23 

 riment, were always taken iri even thousands, 

 I shall proceed now to shew how the time was 

 regulated, in order to ascertain what was^ the 

 duration of one vibration of the latter. 



'■^J:S 



S' ' 



JLengths 



1^-^ 



S 



of Pendulum of 



^■^^ 



^^ 



experiments. 







feetc inch. 



■ 9 



81 



3—3,6995 



12 



80 



3—3,6993 



13 



79 



S— 3,7017 



, 22 



78 



3—3,6955 



23 



78 



3—3,6970 



24 



79 



3—3,6975 



2€ 



78 



3—3,6946 



' 27 



78 



3—3,6970 



28. 



78 



3—3,6970 



29 

 Mean 



78 



3—3,6970 



78.9 



3— 3,6<)81 



(6) See article 23. 



