Rui/al Astronomical Society. 



231 



V=t;(l 4- gsin B L) 

 becomes, in the present case, and according to Captain Foster's ex- 

 periments, 



V = (744.1507482 + 38666418 sin^L) 2 . 

 The following table will show the observed mean value of all the 

 pendulums at each station, as well as the computed value from the 

 above formula, together with the error, or difference, thence 

 arising: and it exhibits the final result ■ deduced from the whole of 

 the experiments. 



The values in the last column indicate most clearly that the pen- 

 dulum is powerfully affected by local circumstances; since the dif- 

 ferences between the observed and computed results, in most of the 

 cases, far exceed the probable errors of observation : and all the 

 pendulums agree in their indication of the degree of intensity at the 

 several places. This fact, however, is rendered more striking by- 

 combining all the experiments hitherto made with the invariable 

 pendulum, by the several English, French and Russian voyaeers. 

 In this manner Mr. Baily has obtained fifty-one different places, 

 where the pendulum has been swung : and at several of these 

 stations it has been swung by more than one experimentalist. The 

 results therefore being, in several instances, confirmed either by 

 the experiments of various persons, or by various pendulums swtiDg 

 by the same person, show most decidedly that there is some local 

 influence on the pendulum, at such stations, with the exact nature 

 of which we are unacquainted ; and which baffles all our efforts to 

 deduce the true figure of the earth from pendulum experiments 

 made at a. Jew places only; for the results deduced from such 

 experiments will vary according to the selection which is made of 

 such stations And it is a remarkable circumstance that the force 

 of gravity seems to be greater in islands situate at a distance from 



