propofed trigonometrical Operation, 
'97 
Comparifon of the celejlial arc of the meridian , comprehended 
between the parallels of Greenwich and Perpignan, with the 
correfponding portions , meafured and computed , of the terreftrial 
arc of the faid meridian , between M Perpignan. 
Ill the confideration of this matter it is to be obferved, that 
M. Cassini has divided the celeftial arc between the parallel 
of Dunkirk,, or, which is the fame thing, between the parallel 
of M and Perpignan, into four principal fed ions ; viz. that 
from M to Paris, from Paris to Bourges, from Bourges to 
Rodes, and from Rodes to Perpignan ; aligning to each fedioiv 
the meafured portion of the correfponding terreftrial arc, refult-- 
ing from the triangles of the meridian. 
By pages no, ill, 1 12, of the firft part of the book it appears, 
from the mean obferved zenith diftances of four Bars, that the arc 
of the heavens, between the parallels of Dunkirk and Perpignan, 0 / fi //; 
contains - — — — — 820226 
And from the mean of the observations of a like number of liars, 
the parallel of Rodes is diftant from that of Dunkirk, — 6 50 51 14. 
Wherefore Rodes is north from Perpignan - 1 39 1 1 1 2 
Bourges, by the mean zenith diftances of two Bars, is fouth from 
Dunkirk, - - - - - 3 S 6 59 55 
Wherefore Bourges is north from Perpignan, - 4 23 2 31 
And by another mean, in p. 112.it is - - 4 23 2 35 
The mean of which two means gives for the diBance of their 
parallels, - - - - 4 23 2 33 
Perpignan 
