508 The Account of a 
177) that the observed angle at Hollingbourn Hill, between 
Allington Knoll and Fairlight Down, was 48° 56' 31", 5, and 
reduce it to 48° 56' 30" for computation ; then from the 
24th, 23d, and 22d triangles, and the triangle 
Hollingbourn Hill - 48° 56' 30" 
Allington Knoll - 88 25 44 
Fairlight Down 42 37 4 6 
we get 141759,6 feet for the distance of Hollingbourn Hill and 
Fairlight Down. 
The distance of those stations as deduced from the other base 
(27404,7) is 141748,5 (see remarks in Vol. LXXX. p. 595) ; 
hence 27404,7 : 27404,2 : : 141748,5 : 141746 feet nearly, 
their distance from the mean of the measurements on Houn- 
slow Heath ; therefore the mean distance resulting from both 
bases is 141753 feet nearly. Now with this distance, and the 
13th, 12th, and 11th triangles, we shall find the distance from 
Hollingbourn Hill to Botley Hill 150971 feet ; and the angle 
at Hollingbourn Hill, between Botley Hill and Fairlight Down 
88° 27' 0A25; these will give the distance from Botley Hill to 
Fairlight Down, 204275,5 feet. 
To determine this line from our triangles, we have 92632,2 
and 117190,4 feet for the distances of Botley Hill and Ditch- 
ling Beacon from Leith Hill ; also 102132,4 and 98513,7 feet 
for the distances of Ditchling Beacon and Fairlight Down 
from Beachy Head ; from these, with the included angles at 
Leith Hill and Beachy Head, we find Ditchling Beacon from 
Botley Hill 139567,4, and from Fairlight Down 167986,5 
feet, and the included angle at Ditchling Beacon 82° 41' 6", 8; 
hence the distance from Botley Hill to Fairlight Down will be 
204276 feet nearly. 
