Trigonometrical Survey. 
519 
f 2 7 2 9 5 U 
I 2 7 2 9 8 >4 
And these applied to the observed angles, give - <j 27 29 5,7 
2 7 2 9 5> 2 
[27 29 6,25 
The mean of which is 27 0 29' 6",i, for the angle between the 
meridian and Jevington staff, being the same as that obtained 
from a mean of the double azimuths. 
art. hi. Determination of the Length of a Degree of a great 
Circle, perpendicular to the Meridian, in Latitude 50° 41'. 
In Tab. XLV. fig. 1. let D and B be Dunnose and Beachy 
Head, and P the pole, forming the spheroidical triangle 
D P B ; and let C and A be the staffs at Jevington and Brad- 
ing Down, respectively. 
Now the angle at Dunnose, between the meri- 
dian and the staff, or PDA, was found by the m , „ 
double azimuths to be - - - - 21 14 11,5 
And the angle between the staff and the sta- 
tion on Beachy Head, or A D B - - 60 42 41,5 
Therefore their sum is the angle between the 
meridian and the station on Beachy Head, or — — 
PDB; which is - - - 81 56 53 
Again ; at Beachy Head the angle between 
the meridian and the staff, or P B C, was found 
by the double azimuths to be - - - 27 29 6 
And the angle between the staff and the sta- 
tion on Dunnose, or C B D - - 69 26 52 
Therefore their sum is the ‘angle between the 
meridian and the station on Dunnose, namely - 9 6 55 58 
3X 2 
