222 Gen. Roy’s Account of 
25284.2 fathoms eaftward from the meridian of the Turnpike. 
Now, the latitude of Calais being 50 57' 30 // nearly (which 
is accurate enough for computation) the length ot the degree 
of a great circle, perpendicular to the meridian in that latitude, 
will be 6:246 fathoms nearly. Hence, 25284.2 fathoms = 
24' 46".8 = the arc CS ; this, with the co-latitude CP (39" 2' 
30"), give the angle CPS = 39' 19". 48, for the difference of 
longitude between the Turnpike and Calais. 
By Comte de Cassini’s Paper, communicated in January 
1789, it appears, that the angle at Dunkirk, between its me- 
ridian and Broulezele, is io° 18' 25" ; and that between Broule- 
zele and Calais 66" 41' 46"!, the fum is 77 o' w '\ for the 
angle at Dunkirk, between its meridian and Calais. In the 
fame Paper we have 19349 34 toifes for the diftance of Dun- 
kirk from Calais; this, with the angle 77 o 1 1 "{, give 
18853.7 toifes or 20093.3 fathoms for the diftance of Calais 
weftward from the meridian of Dunkirk, which, by taking 
61246 fathoms=i° (that of a great circle perpendicular to 
the meridian in the latitude of Calais), is equal to 19 4 1 
=thearcBC; and this arc, with CP the co-latitude of Ca- 
lais, give the angle CPB=3i' I5".H for the difference be- 
tween the meridians of Calais and Dunkirk. 
The angle APR, or the difference of the me- 
ridians of Greeenwich and Goudhurft, has al- 
ready been found (fee the end of the 8th article, 0 , u 
and alfo the table of general refults). 
The angles 
RPS 
SPC 
■ CPB 
= 0 
= 0 
27 39-45 
43 49.86 
= 0 39 19.48. 
= 0 31 1 5. 1 1 
Hence the total angle APB, or long, of Dunkirk, is = 2 22 
A* 
It 
