453 



EDITOR'S NOTES. 



I. On the Ellipticity of the Earth. 



IN the 28th and 29th pages of the German original of this 

 volume (English translation, pp. 27 and 28), M. de Hum- 

 boldt has combined the results of the pendulum experi- 

 ments made by M. Biot, in conjunction with MM. Arago, 

 Chaix, and Mathieu, at several stations of the French 

 arc of the meridian, with those made by myself at several 

 stations in Europe, Africa, and America, (chosen chiefly 

 with reference to their proximity either to the equator 

 on the one hand, or to the high latitudes of the northern 

 hemisphere on the other,) for the purpose of drawing a 

 conclusion upon the important question, whether the 

 acceleration of the pendulum between the equator and the 

 middle latitudes, and between the middle latitudes and 

 the vicinity of the pole, indicates a uniformity, or an 

 inequality, in the amount of the ellipticity derived from 

 those two portions of the hemisphere. The conclusion 

 arrived at is, that from the equator to the latitude of 45 

 the pendulum results indicate T ^ i and from latitude 

 45 to the pole T J-g- ; whilst the three series taken toge- 

 ther give for the whole northern quadrant the ellipticity 



