Trigonometrical Survey. 6j$ 



of the Observatory west of Greenwich. Either of these deter- 

 minations may be taken for the true result, but I shall prefer 

 the first. 



Being favoured by his Grace with the latitude and longitude 

 derived from astronomical observations, we have the following 

 comparisons : 



Degrees. Time. 



T . , J* observed 5i°5°' Z4">9 Longitude west f i° 21' 6",o 5 m 24'^ 

 e -^ com puted 51 50 28,1 from Greenwich. \ 1 21 15,9 5 25,1 



Observatory at Oxford. 



The angle at the station on Shotover, between the Atlas on 

 the top of the Observatory and the parallel to the meridian of 

 Dunnose, is 79°5o' 5i",75 N W: therefore, its distance from 

 the meridian is 14719 feet, and from the perpendicular 416985 

 feet. The figure representing Atlas is 33 -| feet due east of the 

 Quadrant Room ; consequently, no correction will be required 

 in the computed latitude. The space 14719 feet subtends an arc 

 = 2' 24^3, and 416985 feet an arc of i° 8' 3o",8. These data, 

 with the latitude and longitude of Dunnose, give 5 1° 45' 38" 

 for the latitude, and i° 15' 29",2 for the longitude, of the Obser- 

 vatory. As in the former case, with respect to Blenheim, so in 

 the present instance, it is immaterial whether the calculations 

 be carried on from the meridian of Greenwich or that of Dun- 

 nose, as differences of only o",i in both the latitude and longitude 

 are found in the results. 



The latitude and longitude of this Observatory are given in 

 the Requisite Tables ; the first is 51 45' 38", and the last 

 i° 15' 30", or 5 m 2 s in time. Doctor Hornsby, however, has 

 furnished me with what he conceives to be more accurate 



