2I 8 Gen. Roy’s Account of 
M; and let Mg be a portion of a fmall circle of the fpheroid, 
or parallel to the meridian of Greenwich, produced from M 
northward, until it interfecis the perpendicular in the poiat g. 
Alfo, let MP rep refen t the meridian of the Royal Oufervatory 
at Paris, patting through the point M, and interlecling the pa- 
rallel of Greenwich in P. Further, let C reprefen t the 
church of Notre Dame at Calais, and making, as appears by 
the triangles, an angle RMC of *4° 5 [ ' 3 ' *9 v> i:n ^ ie P a " 
rallel to the perpendicular of the meridian of Greenwich drawn 
through the point M. 
From the annexed general table of the refults of the tri- 
angles, it appears, that MR=gG contains 53804'^ feet = 
89674.7 fathoms; and that GR = gM contains 154938 feet = 
25823 fathoms. Now, fince great circles, perpendicular to 
any meridian of the fpheroid, converge towards each other, 
as they depart from that meridian, in the lame manner as the 
meridians themfelves do in departing from tne equator, but 
by a flower rate, it is obvious, that the perpendicular to the 
meridian of Greenwich, patting through the point M, mutt: 
fall below or to the fouthward of R 011 that meridian, lo as 
that Gr : GR :: rad. : cofine MR = i° 27' 514 conttdered as 
a portion ot a great circle of the fpheroid, perpendicular to 
the meridian of Greenwich. Hence, Gr will contain 2583 1.43 
fathoms = 25' 2 y // .() of latitude, and therefore the latitude of 
r will be 51 0 3' I2".i, audits co-latitude 38° 56' 47A9. Alfo, 
R r meafures 8.43 fathoms, and fubtends an angle RMr = 
19A42. 
In the right-angled fpherical triangle, pole rM, right- 
angled at r, making ufe of the half fum and half difference 
of the containing Tides, r pole and rM, with the co-tan- 
gent 
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