[ Soo ] 
XLIX. An Account of Obfervathns made on Moun^ 
tain for finding its AttroBion. By the Rev. 
Nevil Maikelyne, J5. D. F, R, S, and AJirononur RoyaL 
Redde, July 6, T the year i77i, I prefented the forego- 
ing propofal, for meafuring the attrac- 
tion of fome hill in this kingdom by aftronomical obfer- 
vations, to the Royal Society ; who, ever inclined to pro- 
mote ufefnl obfervations which may enlarge our views 
of nature, honoured it with their approbation. A com- 
mittee was in confequence appointed, of which number 
I was one, to conlider of a proper hill whereon to try the 
experiment, and to prepare every thing necelTary for car- 
rying the defign into execution. The Society was already 
provided with a ten-feet zenith fe61or made by Mr. sis- 
soN, furnillied with an achromatic object glafs, the prin- 
cipal inftrument requilite for this experiment, the fame 
which I took with me to St. Helena in the year 1761;^ 
vvhich wanted nothing to make it an excellent inftru- 
ment but to have the plumb-line made adjuftable, fo as to 
pafs before and bifedt a fine point at the centre of the in- 
ftmmenh This was ordered to be done, and a new 
wooden ftand provided for it, capable of procuring a mo- 
tion of the fedlor about a vertical axis, by means of which 
it could -be more eafily brought into the plane of the me- 
ridian, 
