2io Gen. Roy’s Account of 
with the former, although the latitude of B be now taken on a 
fphere whofe degrees contain 61253! fathoms, it obvioufly 
follows, from thefe recent obfervations, that whatever the prc- 
afe figure of the earth may be, or the ratio between its diameters , 
the degree of a great circle upon it perpendicular to the meridian , 
cannot in thefe latitudes differ much in length from 6 1 fathoms. 
Art. V. The pole far obfervations at Folkfone Turnpike applied 
to computations on the fame greater fphere. 
Let G (Plate X. fig. 6.) be Greenwich; PR its meridian; 
F, H, and T, the Rations at Fairlight Down, High Nook, and 
Folkfione Turnpike, refpe&ively ; alfo let PF and PT be me- 
ridians paffing through F and T ; and FR and T r great circles 
cutting the meridian of Greenwich PR at right angles in R and r . 
At the Ration T, on the 7th of September, 
1788, at night, the angle between the pole-flar, 
when at its greateR apparent elongation from the 
pole on the eaR fide of the meridian, and the re- 0 , „ 
verberatory lamp at H, wasobferved, . 1 23 1 9 3! 
On the following morning, Sept. 8th, the 
angle between the Rar, when at its greateR 
diffance on. the weR fide, and the flag-Raff at H, 
was obferved, . . • IX 7 3 ° 5 2 ^ 
The difference or double azimuth is, . 5 48 io| 
And the half fumis, . . 120 24 57.87 
This half fum 120° 24'' 57 // .8y * is the angle PTH, or that 
comprehended between the meridian PT and H. The angle 
HTF, 
* By taking the latitude of T as determined on M. Booguer’s fpheroid,— 
-j° 2' 45^.3 nearly, the co-latitude or TP is equal to 38° £ 4 / * 7 > an( ^ 
flax’s apparent diftance at the time being 1° 48' i 8".03, we have, as fine 
38 ° 
I 
