604 Mr. Dalby’s Remarks on Gen. Roy’s Account 
Dover Caffe 
o 
Swingfield 
79 
Padlefworth 
81 
Folkftone Turnpike 
6 5 
Montlambert 
27 
Blancnez 
5 1 
Calais • 
64 
Dunkirk 
<"0 
OO 
by M. Cas- 
sini’s diffance of 
Dunkirk and Calais 83 
Point M . 82 
27 47.8 NW 
11 30.1 sw 
52 45.6 sw 
56 54.8 SE 
21 c c.i SE 
8 37.1 SE 
22 52.9 SE 
22 50.2 
33 14.4 SE 
The difference between the complement of 82° 33' i4 // .4 and 
the angle at M in the XL triangle is 14 0 5 1 7 3A9, the angle 
RMC referred to in Art. 10. and 11. Se£L VI. 
P. 194. It is faid, that the angle ABu (PL X. fig. 2.) is 
equal to the angle BAr, and conl'equently at p. 199. that the 
fum of the obferved angles PAB, PBA, are equal to the fum 
that would be found on a fphere. This (though extremely 
near in any of the fpheroids hitherto affumed for the figure of 
the earth) is not geometrically true when the points of obfer- 
vation are on the furface of the fpheroid, and each angle taken 
exactly in the plane of the horizon. For, it is evident, that to 
have the fum accurately the fame, the points A , B (the places 
of obfervation) muff: be at equal diftances from G and W ; and 
therefore, if at any two points thus taken in the verticals GA, 
WB, the angles are fuppofed to be in planes parallel to the 
refpe£tive horizons at A and B, their fum will always be the 
fame. Hence, becaufe the vertical WB is greater than GA, 
if the angles are accurately horizontal ones at A and B, their 
fum muff; he greater on the north fide, and le/s on the fouth, 
than 
