Relating to the FIGURE of the EARTH. 17 



19. We may apply thefe formulas to the computation of -» 



&c. from the degrees of the meridian and perpendicular, mea- 

 fured in the fouth of England. We find, in one example, 

 (Phil. Tranf. 1795, p. 537-)» tnat D = 60851 fathoms, D' = 



61 182, the latitude, or <p being = 50 . 41'. From this c - — 



n ~~ r . = — ^ — .. w 3 . 3I f>H , .., = — 5—, which is nearly the 

 2B cof a p 2 X61182 x (.coi 50°. 41 y 143.4' J 



fame refult with that deduced in the pafTage juft referred to. 

 Indeed the folution of this problem, contained in the Trigonome- 

 trical Survey , is quite unexceptionable ; and the theorems here 

 offered are not given as containing a more accurate folution, 

 but one that is in fome refpecls more fimple. 



The above comprefTion, if the remarks already made be well 

 founded, is much too great, being more than double of what 

 was obtained from comparing the whole arch of the meridian 

 meafured in France with the whole of that meafured in Peru. 

 At the fame time it is right to obferve, that all the other com- 

 parifons of the degrees of the meridian, with thofe of the 

 curve perpendicular to it, made from the obfervations in the 

 fouth of England, agree nearly in giving the fame oblatenefs 

 to the terreftrial fpheroid. For this circumflance, it is certain- 

 ly not eafy to account ; the unparalleled accuracy with which 

 the whole of the measurement has been conducted, makes it 

 in the higheft degree improbable that it arifes from any error ; 

 and even if errors were to be admitted, it is not likely that 

 they fhould all fall on the fame fide. The authors of the Tri- 

 gonometrical Survey feem willing, therefore, to give up the el- 

 liptic figure of the earth, {Ibid. p. 527.) ; but before we aban- 

 don that very natural and fimple hypothefis, it may perhaps 

 be worth while to attend to the following confiderations. 



Part I. C In 



