53 2 The Account of a 
from the meridians, and their perpendiculars from those re- 
duced, or pyramidical angles and the chords or sides of the 
triangles, independent of other data, would be very tedious. 
Great accuracy however, in these cases seems not absolutely 
necessary ; because, if the latitudes and longitudes obtained 
from those distances can be depended upon to \ of a second 
(the latitude of Greenwich, from which the other latitudes are 
derived, being supposed exact), the conclusions will certainly 
be considered as sufficiently near the truth : 25 feet answers 
to about \ of a second on the meridian ; and it is not difficult 
to show, that no uncertainty of more than about 10 feet has 
been introduced, even in the longest distances, in consequence 
of using the observed angles. 
As Botley Hill is nearly south of the Observatory at Green- 
wich, and it may be supposed, that the distance of it from the 
meridian, as well as perpendicular, must be nearly true, as 
given in the Philosophical Transactions, it has not been con- 
sidered as expedient to make this part of the operation entirely 
independent of General Roy's, by selecting Greenwich for a 
station, and observing the direction bf the meridian at that 
place with respect to Banstead, or Shooter's Hill. 
In order, therefore, to obtain the necessary data , when the 
instrument was at Botley Hill, the angle between Banstead 
and the station on Wrotham Hill was observed, as given in a 
former part of this work, and found to be 152*5/ 4",25 ; from 
which subtracting 7 g° 1 6' 28", *75, the angle which Wrotham 
Hill makes with the parallel to the meridian of Greenwich, 
(Phil. Trans. Vol. LXXX. p. 601.) we get 73* 40' 35", 5 for the 
inclination of Banstead to that parallel ; this, with 50327 feet, 
the distance from Banstead to Botley Hill, give 48874,2 feet. 
