5 ° 3 
Trigonometrical Survey. 
these triangles been considered as independent of those in the 
first branch, and the side Hind Head and Leith Hill been used 
as derived from the base on Hounslow Heath, nearly the same 
conclusions would have taken place ; for the distance between 
Beacon Hill and Old Sarum would in that case be 36574,2 feet, 
which is only two and an half inches less than the measured base. 
This may be considered as a proof, that the angles of the tri- 
angles forming this branch are sufficiently correct, since the 
series which joins the two bases by this route, is nearly an hun- 
dred and twenty miles in extent. Some little variation in that 
result might be produced by a different correction of the angles 
of the 24th triangle : but as the angle at Butser Hill must be 
very nearly true, the other angles cannot, on any reasonable 
supposition, be so corrected as to make the computed base differ 
from the measured one more than six inches. 
art. vi. branch hi. Proceeding from the Side Hanger Hill and Ban- 
^tead to Botley Hill and Leith Hill, and from thence to Brightling and 
Beachy Head, joining the Triangles with those of the late General Roy, 
at Botley Hill and Fairlight Down, being bounded to the westward by 
the Sides connecting the Stations Hanger Hill, Banstead, Leith Hill, 
Ditchling Beacon, and Beachy Head. 
Hanger Hill from Banstead 77547,4 Feet. 
No. of 
triangles 
Names of stations. 
Observed 
angles. 
Diff. 
Spheri- 
cal 
excess. 
Error. 
Angles corrected 
for calculation. 
Distances. 
XXX. 
Shooter’s Hill 
Hanger Hill 
Banstead 
54 43 49>75 
62 18 50 
62 57 22 
" 
" 
" 
54 43 49- 2 5 
62 18 49,5 
62 57 21,25 
Feet. 
180 0 1,75 
M 
+ °>35 
Shooter’s Hill ( Hanger Hill - 
\ Banstead 
84596,3 
84107 
3T 2 
