the Trigonometrical Operation . 2 g 
taken in the mod convenient place inland on the range of 
chalk hills, vifible from the place of explofion, and the eafieft 
connected with the triangles of the meridian of Paris in the 
neighbourhood of Helfaui and Bouvigny. Crowhorough is about 
70 miles diftant from Montlambert, and a point in the direction 
of thefe two near Helfaut would be about 32 miles inland from 
Montlambert , which would give for the extreme diftance about 
102 miles. 
If experiments of the fame kind were to be made to the 
weitward of Greenwich, thofe very ftations, already propofed 
for the continuation of the triangular operation, would be the 
fitted: that could be chofen for the purpofe. 
Now, fuppofing the operations already mentioned in the 
parallel of Greenwich to be executed, the meridian of Pen-y- 
Voel Hill extended to the northern extremity of Scotland, and 
three degreees of longitude meafured in that latitude, while 
the Eaft India Company were carrying on operations of the 
fame nature on the coaft of Coromandel and in Bengal, every 
thing would then be done that Britain could do within her 
own dominions, in regard to the determination of the figure 
and dimenfions of the earth. If, after this, any doubts re- 
mained, thefe might eafily be removed, by Portugal’s mea- 
furing a degree or two of the meridian under the equator, and 
alfo a portion of the earth’s equatorial circnmference ; while 
fome other nation repeated the operations at the polar circle, 
or made new ones ftill nearer to the pole, if fuch Ihould be 
found practicable, all which has been fuggefted in the Paper 
of 1787. For the farther illuftration of this fubjed, it will be 
proper to refer to fig. 3. in Plate X. 
With regard to the execution of any future operation that 
may, and which it is hoped will, be hereafter undertaken in 
Mm2 " Britain, 
