the 'Trigonometrical Operation. 
207- 
Auguft 23, 1788, at Botley Hill, the angle 
&BW, or that between the pole-ftar at its greateft 
apparent elongation and the lamp at Wrotham 
Hill, was obferved, . . . 76 21 27 
The angle WBG, by repeated obfervations, was, 40 4 42 
Their fum = angle *BG is, . . 1 16 26 19 
In order to obtain the ftar’s azimuth at each place, we may 
take, without producing any fenfible error, the latitudes of G 
and B, as they would be found on M. Bouguer’s figure, 
which we have already announced, and will hereafter prove to 
be confiftent with obfervation. Thus B, or Botley Hill, is 
fouth from Greenwich 72882! feet, and nearly on the fame 
meridian; wherefore its latitude will be 51 0 16 7 4i /7 .54, and 
its co-latitude BP of courfe 43' i 8 7 '.46. Now, P% 
the apparent diftance of the ftar from the pole at that time 
beings c° 49 7 22 / .§4, in the right-angled fpherical triangle 
P-^-B, we have fine BP : rad. :: P* : fine 2 0 54 / 54 // .2 equal 
to the angle -&BP, the ftar’s azimuth from the north. And 
this being added to the angle -^BG obferved 1 1 0° 2 b 7 we 
have the angle -&BP = 1 19 0 2i 7 13R2 for that comprehended 
between the meridian and Goudhurft. 
The diftance of Goudhurft from the perpendicular to the 
meridian of Greenwich is 132592 feet, and its diftance from 
the meridian of Botley Hill, on a perpendicular to that meri- 
dian, is 106171 feet nearly = GR. Hence the latitude of the 
point R is 51 0 6 7 52A89 ; therefore RP — 38 0 53' , and 
RG =106171 feet=; I7 7 1 9 7/ -7 nearly. Hence, as rad. : cofine 
KP :: cofine RG : fine 51° 6 7 49 7/ . 7, the latitude of G nearly; 
therefore GP — 38° io 77 .3 ; and P*- the ftar’s apparent 
diftance at the time being i Q 49 / 25A34, we have the angle 
PG 
