The Account of a 
564 
Triangles for finding the Distance of Portsmouth Observatory 
from Dunnose. 
Dunnose from Motteston Down 55104,3 feet. 
No. 
Triangles. 
Angles 
observed. 
Distances of the stations from 
the intersected objects. 
155 
Dunnose - 
Motteston Down - 
Spindle of the Wind 
Vane on Portsmouth 
Church Tower 
92 44 48 
48 44 27 
1 Portsmouth J 
J Church [ 
Feet. 
66524 
8 8393 
156 
Dunnose - 
Motteston Down - 
Ball of the Cupola of 
Portsmouth Academy 
9 1 35 3 2 
5° 43 3 6 
1 Portsmouth Aca- f 
j demy - | 
C3787 
90113 
In order to ascertain the situation of the Observatory, Mr. 
Bayly, Master of the Academy, measured two angles in the fol- 
lowing triangle, viz. 
* 1 n 
Portsmouth Academy 124 9 15 
Observatory - 53 6 15 
Portsmouth Church 
The included angle at Dunnose between the Ball on the Cu- 
pola of the Academ}', and the Spindle of the Wind Vane on 
Portsmouth Church, is i° 9' 1 6", and the distances of those ob- 
jects from Dunnose are 66524 and 69787 feet ; therefore the dis- 
tance between the Academy and the Church will be 3540 feet : 
