654 PHILOSOPHICAL TRANSACTIONS. [aNNO 1795. 



Latitude and Longitude of Chanctonbury Ring. 



Latitude of Chanctonbury Ring 50" 53' 48".5 



I,ongitude of Beachy Head, east of Greenwicli 15 11. 9 



Longitude of Chanctonbury Ring, west of Beachy Head .... 37 58.8 



Longitude of Chanctonbury Ring, west of Greenwich 22 46 .9 — in time 1" 31'.l 



Latitude and Longitude of Dunnose. 



Latitude of Beachy Head 50° 44-' 23" .7 



And taking 6'0o5I fathoms for the length of tlie degree upon'^ 



the meridian, we get 442.^9 feet, the distance between > 7 l6 -4 



the parallels of Beachy Head and Dunnose J . 



50 37 7 .3 latitude of Dunnose. 



The difference of longitude between Beachy Head and Dun- 1 ^,. „ 



nose has been found in the preceding section J i -J 



And tlie longitude of Beachy Head, east of Greenwich .... 15 1 1 .9 e 



Therefore the longitude of Dunnose, west of Greenwich, is 1 11 36' and in time 4" 46'. 4 



Latitude and Longitude of the Stations referred to the Meridian of Dunnose. 



Names of Stations. 



Rook's Hill 



Hind Head 



Butser Hill 



Motteston Down . . 



Highclere 



Dean Hill 



Beacon Hill 



Four Mile-stone . . 

 Thomey Down .... 



Old Sarum 



Nine Barrow Down 

 Wingreen 



The longitudes and latitudes of the stations have been computed spherically, 

 in which we have taken the degrees on the meridian, and of the great circle 

 perpendicular to it, from the following table. 



Latitude 



Degrees on the 

 merid. perp. 



Fath. Path. 



61182 j) Semi-transverse of this ellipsoid 



61185 VSe ■ 



61188) 



Fathoms. 

 .3491420 



mi-conjugate 3468007 



Ratio of the axes 1 to 1.006751 



This ellipsoid is determined from the length of the degree obtained from the 

 directions of the meridians at Beachy Head and Dunnose, and that on the me- 

 ridian in lat. 50° 41', as resulting from the application of the measured arc be- 

 tween Greenwich and Paris, to their difference in latitude. It is not however 

 to be understood, that by using it we consider the earth to be this ellipsoid : we 

 have adopted the hypothesis, because it is obvious some small increase northward 



