x 86 Gen . Roy’s Account oj 
angles, to bring out thefe different refults, we (hall abide by 
the firft, that being immediately produced by the mean of the 
obfervations without any arbitrary correction whatever ; and 
being, with regard to eafting, nearly a mean between the two 
extremes ; and fince we have it in our power to fettle with 
great precifion the longitude of Dunkirk, and likewife the 
point M, with regard to Greenwich, we (hall then be enabled 
to determine the difference of longitude between the two Royal 
Obfervatories within a mere trifle of the truth. 
By Comte de Cassini’s triangles, executed in the autumn of 
1787, and communicated in January 1789, it appears, that 
Hondfcote is fouth-eaftward from the meridian of Dunkirk 
6?° 53 ' 2Q,/ 5 which angle being fubtradled from the total 
angle between Hondfcote and Calais 144 0 53" 28 // .5, being 
the fum of the three angles at Dunkirk in the XLth, XLlft, 
and XLIId triangles, there remains 77 0 o / 8 '. 5 for the angle 
that Calais is fouth-weftward from the meridian of Dunkirk. 
And this laft angle being again fubtrafted from 180°, we have 
102 0 59 / 51" . 5 for the angle between the fame meridian pro- 
duced northward, and a line drawn from Dunkirk through M 
to Calais. 
Now the two diftances 13 3775*3 and 1513*8 fathoms being 
feverally reduced in the proportion of 39809.94 to 39808.7 
the two lengths affignable to the bafe on the Strand near Dun- 
kirk, as formerly eftablifhed, we have 1 33 771.1 fathoms for 
the diftance in Britifh meafures of the parallel of Dunkirk 
from that of the Royal Obfervatory at Paris; and 1 51575 
fathoms for the diftance of Dunkirk eaftward from its meri- 
dian. Again, making ufe of the angle 7 7 0 o' 8A5, and its 
complement to 90°= 12° 59' 51A5, we have 1553.56 fathoms 
for the direCl diftance between Dunkirk and the point M ; 
2 alfo 
