io6 Mr. Topping's Account of the Measurement 
Angle at N 5 0 3 6' 30' 
^ A 177 24 40 
B 176 23 o 
C 178 1 15 
Angle at D 178° 37' 30 1 
E 177 2 o 
A S 6 53 o 
With which proceed thus : 
NAB i77°24' 40" 
Its supplement ■ — 2 35 20 
from 5 36 30 z. N 
gives 3 1 10 z. required at A. 
ABC 176° 23' o' 7 
3 37 0 
- 3 1 10 
o 35 50 z. required at B. 
BCD 178° 1/ 15" 
1 38 45 
+ o 35 50 
z_ required at C 2 34 35 
CDE 178° 37' 30" 
1 22 30 
+ 2 34 15 
DES 177 0 2' o" 
2 58 o 
+ 3 57 5 
6 55 5 ^ req. at 
E or S. Diff. only 2' 
from the ob- 
served angle o 
z. required at D 3 57 5 
