ON THE ELLIPTICITY OF THE EARTH. 471 



symmetrical consistency of the ellipticity of the two 

 portions of the northern quadrant shown by the ac- 

 celeration resulting from the employment of Kater's 

 invariable pendulum, I may be permitted to rectify 

 an accidental mistake which occurs in p. 27 of the 

 original (p. 27 of this translation also), regarding the 

 the origination of the experiments in which I was myself 

 employed. The experiments of Captain Kater at the 

 principal stations of the British Trigonometrical Survey 

 were those which were undertaken, as stated by M. de 

 Humboldt, at the desire of H.M. Government, pursuant 

 to an address of the House of Commons, March 15th, 

 1816, which was moved by Mr. Davies Gilbert. This 

 undertaking was completed on June 19, 1819, when 

 Captain Kater presented the final account of his experi- 

 ments to the Royal Society. The subsequent extension 

 of the inquiry to stations including "the utmost accessible 

 distance on the meridian of a hemisphere," originated in 

 a proposition made by myself to the Board of Longitude, 

 and recommended by that board (which included 

 amongst its members several of the most eminent Fel- 

 lows of the Royal Society) to the favourable considera- 

 tion of H.M. Government. The object of the proposition 

 is stated in the preface of the work in which its accom- 

 plishment is recorded, viz., "to extend the suite of 

 stations to the equator on the one side, and to the highest 

 accessible latitudes of the northern hemisphere on the 

 other ; to multiply the stations at both extremities of 

 the meridian, so that, by their general combination, the 

 irregular influences of local density (which had prevented 

 any independent conclusion whatsoever, relatively to the 

 figure of the earth, being drawn from the experiments 



