5 o6 
The Account of a 
art. v. Of the Distances of the Objects in the Scilly Isles, (inter- 
sected from. the Stations in the West of Cornwall) from Sennen 
Steeple; the Stone near the Land’s End; and the Longship’s 
Light-house. 
As the observations made to the Day Mark, and St. Agnes’ 
Light-house, may be supposed sufficiently accurate; and the 
ball on the top of the Longship’s Light-house was also ob- 
served under favourable circumstances, it will be proper to 
apply the corrections to the horizontal angles, in order to obtain 
those formed by the chords. Taking, therefore, Pertinney as 
the angular point, and computing with the following data , viz. 
Station on Pertinney from 
the angle at Pertinney, augmented 
for calculation, between the Long 
{ Day-Mark 
St. Agnes’ Light-house 
Longship’s Light-house ~ 27883 J 
= 1 5-4-5 5 1 
— 182207 }>Feet. And 
:r 
the Day-Matk 
= 12 0 17' 30" H We get the 
, ] St. Agnes’ Light-house = 6 15 25 (distance of 
ship’s Light-house and ^ 5 ° J 
the Longship’s Light- f the Day-Mark - = 127446 feet -= 24, 14! 
house from - ] St. Agnes’ Light-house = 1545 19 feet = 29,06 j 1 
Calculating also, with the distances of the two other objects 
in the Scilly Isles, and likewise those of Sennen Steeple, and 
the Stone near the Land’s End from Pertinney, with the inclu- 
ded angles at the same station, we get 
Feet. Miles. 
= 139521 = 26,43 
= 166255 = 31,49 
= 157912 = 29,95 
from 
f Day Mark 
Sennen Steeple | St. Agnes’ Light-house 
Flagstaff in St. Mary’s 
Windmill in St. Mary’s = 155299 = 29,41 
(“Day Mark - - = 135343 = 2 5^3 
I St. Agnes’ Light-house = 162100 = 30,7 
1 Flagstaff in St. Mary’s = 153744 = 2 9>n 
^Windmill in St. Mary’s = 15 11 38 = 28,63 
Stone near the 
Land’s End 
from 
