49 S The Account of a 
No. of 
triangles 
Names of stations. 
Observed 
angles. 
Diff. 
Spheri- 
cal 
excess. 
Error. 
Angles corrected 
for calculation. 
Distances. 
XV. 
Old Sarum 
Thorney Down 
Beacon Hilt 
0 , „ 
48 26 4,5 
98 031 
33 33 2 4>75 
§ 
// 
1 
0 , // 
48 26 4,5 
98 0 30,75 
33 33 2 +7S 
Feet. 
fT 
d 
0 
0 
00 
1 
°>*3 
+ 0,12 
Old Sarum from Thorney Down 
-- 
20416,1 
XVI. 
Four Mile-stone 
Dean Hill 
Beacon Hill 
72 4 48 
39 2 9 3> 2 5 
68 26 10 
7 2 4 47»5 
39 2 9 3 
68 26 9,5 
00 
0 
0 
°>5 
+ 0,75 
Four Milestone { g ill 
56775>° 
38818,2 
XVII. 
Old Sarum 
Four Mile-stone 
Beacon Hill 
85 58 22,5 
70 I 47,5 
23 59 5i-75 
85 58 21,75 
70 1 47 
23 59 51,25 
- 
180 c 1,75 
0,14 
+ 1,61 
Old Sarum from Four Mile-stone 
- 
15826,4 
art. iv. The Length of the Base o/* Verification deduced from 
that on Hounslow Heath, and the foregoing Triangles. 
The base on Hounslow Heath is 27404,2 feet, which, with the 
four first triangles, give 76688 feet for the mean distance of St. 
Ann's Hill and Banstead. 
That mean distance, with the 5, 6, 7, 10, 11, 12, 13, 16, and 
17th triangles, will give 36574,7 feet for the base of verification. 
If the computation be made with the 8 and 9th triangles also, 
and the mean distance taken between Hind Head and Bagshot, 
the base will be 36574,3. 
