206 Gen. Roy’s Account of 
when at Fairlight Down we had no obfervations of the ftar, 
being at that time fo much engaged with the other effential bufi- 
nefs of the triangles, and particularly with the interfeftion of the 
lights on the Coaft of France, as to render it impoffible to 
attend to any thing elfe, even if the weather had proved lets 
unfavourable than it was at the period alluded to, for celeftial 
obfervations. 
Art. III. Pole-far obfervations at Goudhurf and Bothy Hill 
applied to computations on the mean fphere . 
Let B (Plate X. fig. 5.) be Botley Hill ; PER its meridian ; 
GGoudhurft; W Wrotham Hill ; T Tenterden; RG an arc 
of a great circle paffing through G, and falling perpendicu- 
larly on the meridian BR ; alfo let % % rep refen t the circle of 
the pole-ftar’s apparent declination; and B*-, G*, be two 
azimuth circles touching that circle. 
Auguft 14, 1788, at Goudhurft, the angle 
#GT, or that between the pole-ftar, when at its 
greateft apparent diftance from the pole on the eaft 
fide of the meridian, and the reverberatory lamp 
at Tenterden was obferved t, • • 104 32 19I 
The angle BGT, between the lamp at Botley 
Hill and Tenterden, was repeatedly obferved, 167 43 56 
Their difference — angle -*GB is, , 63/1 36! 
f The obfervations of the pole-ftar at Goudhurft and Botley Hill were repeated for 
feveral nights at each place ; but thefe here given are the inoft exa£t. At Goudhurft 
the angle which the ftar made with the lamp being noted, the telefcope removed, and 
the plane of the inftrument being turned 180 0 , or half round, the telefcope re- 
placed and directed again to the ftar, the difference on the circle was found to be 
only i"J. The fame method was univerfally adhered to in all places where 
obfervations of the ftar were obtained. At Botley Hill, in particular, the dif- 
ference between the readings was no more than i"4. 
Auguft 
