of the Trigon$?netncdl Operation . 6 1 1 
^ 2C 97 02 55 will be the radius of curvature nearly. The 
height of the ftation above low-water fpring-tides (as deter- 
mined by alternate obfervations at this place and Dover Caftle) 
was 642 feet ; hence ,999969386 1 the natural co- 
fine of 26' 54" the dip ; therefore 26 ' 54^ — 26 7 27 // = 27 // is 
what the horizon was elevated by refraction. The ftate of the 
tide however, is not taken into confideration ; but the time was 
about noon. 
The weather was calm and cloudy, and the horizon clear# 
Barometer 29.6, Thermometer 70°, at 1 P.M. 
The above obfervation was made with great care and attention. 
P. 249. in the 3, triangle, for 7680 ^5 put 76812.4, 
The opeiations alluded to in the note at the botttom of this 
page were, 
Angles obferved at f Richmond Ob. and the Pagoda 13 10 13 
Spnng-Grove < The Pagoda and St. Paul’s 23 17 15 
Houfe between l St Paul’s and Harrow Spirp 74 18 43 
Angles taken on fStretham Church and St. Paul’s 70 24 5 2 
Fulham Churchj St. Paul’s and Hampftead Church 44 50 46 ' 
between lHamp. Ch. and Hanger H. Tower 57 2 7 43 
, I n l 7 % 7 > at Hanger Hill, the angle between Richmond Ob- 
fervatory and the Pagoda was obferved 1 2 0 26' 42". At the 
Hundred Acres, that between Hanger Hill and Batterfea 
Church 23 0 51/ 44"; and that between Hanger Hill and Strut- 
ham Church 42 0 3' 57". The angle at St. Paul’s between 
Batterfea Church and the SW Pinnacle of Weftminfter Abbey 
is 9' 45 // .6. 
The refults from the obfervations made on Fulham Church 
cannot be conlidered as very exa£t, becaufe Hanger Hill Tower 
4 K 2 itfelf 
