214 Gen. Roy’s Account of 
their parallels, which on this fpheroid correfponds to 27248.2 
fathoms, lefs only by 1.1 fathom than the fpace found, in the 
laid article, to anfwer to an arc of 26' 4i /7 .5, being the dii- 
tance of the fame parallels on the greater fphere. 
Thus the meafured length of the arc between Greenwich 
and M, 27248.2 fathoms, being added to the meafured dis- 
tance of M from the Royal Obfervatory at Paris, we have for 
the total length of the arc between Greenwich and Paris 
160658 fathoms, which exceeds the computed length or the 
fame arc on M. Bquguer’s hypothecs by no more than 7 f 
fathoms. 
Rut it hath been already fhewn, that whatever the precife 
figure of the earth may be, a degree or a great circle upon it, 
perpendicular to the meridian, cannot in thefe latitudes differ 
much in length from 6125.51 fathoms, being but i6| fathoms 
Jefs than 61270 fathoms, the length of the correfponding 
degree on M. Bouguer’s fpheroid. 
As far therefore as we are enabled to judge from the refult 
of thefe obfervations, the earth differs but little either in its 
latitudinal or longitudinal dimenfions from what hath been 
affigned to it by M. Rquguer. 
Art. VIII. .Application of the pole far obfervations at Botley 
‘Mill and Goudhurf , for determining the length of the degree of 
a great circle, perpendicular to the meridian. 
Since M. Rouguer’s fcale for the degrees of the meridian 
hath been found to agree almoft exa&ly with obferved latitudes 
in this part of the earth, let us take the latitudes of B and R 
(fig. 5.) as they would be found on his fpheroid nearly, and 
apply the pole-ftar obfervations at B and G, in order to find 
the length of the degree of a great circle, perpendicular to 
7 the 
