442 THE YARD, PENDULUM, AND METRE. 



Schubert however, arbitrarily, and as I think quite inde* 

 fensibly, rejects altogether the result of the French arc r 

 ?nd assigns to the Russian double the weight of the 

 Indian ; a mode of precedure in which he will find, I 

 presume, few to agree with him. A much fairer, indeed 

 the only fair way to treat them, is obviously to ascribe to 

 each of the separate results in taking the mean, a 

 weight proportional to the total extent of the arc, and 

 this gives for the length of the axis 41,708,710-0 feet. 

 Comparing then the final results of the two modes of 

 procedure we find, 



From the former, 41,707,467 feet. 



And from the latter,. 41,708,710 



which differ only by 1 243 feet, or less than ^ of a mile . 

 so that their mean or 41,708,088-5 f. is in all probability 

 within a furlong, or one part in 64,000 of the truth. 



(25.) From each of the great arcs of Russia and India, 

 M. Schubert then obtains a separate value of the equa- 

 torial or the larger axis of the elliptic meridian to which 

 it belongs ; and by a similar treatment of the arc of Peru, 

 which, lying under the equator, is especially favourable 

 for the purpose, he obtains a third value of the equa- 

 torial diameter. The three diameters of the equatorial 

 ellipse thus obtained, with the angles they include at the 

 centre (which are the differences of longitude of the re- 

 spective meridians, and which are as favourably arranged 

 for the purpose as the nature of the case seems to admit), 

 suffice for the determination of the major and minor axis- 

 of the equator, regarded as an ellipse, and the longitudes 

 in which they lie, viz. : 



