598 Mr. Calby’s Remarks on Gen. Roy’s Account 
P. 182. &c. The triangles after the XXXVI, and what fol- 
lows to the end of the article, do not feem neceflfary, on our 
part, to complete the triangular connection between Green- 
wich and Paris, becaufe it may be done in the following man- 
ner from the triangle formed by Dover, Calais, and Dunkirk, 
In this triangle, the fide between Dover and Calais is 157449.9 
feet (fee the XXX VI triangle); and by M. Cassini’s Paper, 
communicated in 1789, it appears, that the fide between Ca- 
lais and Dunkirk is 19549.34 toifes (= 123729.3 feet), and the 
included angle at Calais 139° 35 .6 ; thefe give 19" 14' 
I3 // .i and 21 0 28 / 11X3 for the other two angles, and 244919 
feet for the diftance of Dover and Dunkirk; alio 28232.7 for 
what Dunkirk is fouthward, and 243 2S 7 feet for what it i9 
eaftward, from Dover : this laft added to 307366.8, the dif- 
tance of Dover from the meridian of Greenwich, gives 
547053.8 feet for what Dunkirk is eaft from the meridian of 
Greenwich on a parallel to the perpendicular ; but the length of 
the arc of the great circle which paffes through Dunkirk, and 
is perpendicular to the meridian of Greenwich, is very near 
the fame as the length of this parallel, or 547053.8 feet (though 
accurately fomewhat lefs) ; hence, if we take 61247! fath. = 
i°, we have i° 2$ / 19T1 for that arc, and the latitude of 
Dunkirk being $ l ° z' 9 // *3 (See Se<ft. VI. Art. 12.); there- 
fore, cofine 51 0 'll 9". 3 : rad, :: fine i° 29' : fine 2 0 
22 7 5 /7 .8 the longitude of Dunkirk (agreeing with that in 
Art. 12.); and rad. : tang. 51 0 2' 9' ' *3 :: tang. i° 29' 19A1 : 
cofine 88° g / 34 7/ for the other angle of this triangle of which 
the co-latitude of Dunkirk is the hypothenufe. 
Dunkirk is eaft from the meridian of Paris 1416, or 1430 
toifes (fee Art. 12. Se<St. VI.), a mean of thefe give i 7 29 /7 .i4 
as an arc of a great circle; this, with the co-latitude of Dun- 
c kirk 
j 
