4 i3 Mr. Pigott’s Determination of 
.Were the following circumftances attended to, the refults 
would undoubtedly be much more exadt. 
i ft, Compare the obfervations to the fame made in feveral 
other places. 
2dly, Let feveral and the fame ftars be obferved at thefe 
places. 
^dly, Such ftars as are neareft in R.A. and declination to 
the moon are infinitely preferable. 
4thly, Your advice to get as near as poffible an equal num- 
ber of obfervations of each limb, to take a mean of each fet, 
and then a mean of both means, cannot be too ftrongly urged. 
I am perfectly of your opinion, that it will confiderably correct 
the error of telefcopes and fight. 
5 tlily. The adjuftment of the telefcopes to the eye of the 
obferver before the obfervation, which you alfo recommend, 
will appear very judicious to every aftronomer, who muft have 
frequently perceived what you mention, that the fight is 
fubjedt to vary. 
6thly, As a principal error proceeds from the obfervation of 
the moon’s limb, I think it may be confiderably leffened, if 
certain little round fpots near each limb were alfo obferved in 
fettled Obfervatories ; in which cafe the libration of the moon 
will perhaps be a confideration. 
^thly, When the difference of meridians, or of the latitudes 
of the places, is very confiderable, the change of the moon’s 
diameter becomes an equation. 
Though fuch are the requifites to ufe this method with 
advantage, only one or two of them have been employed in 
the obfervations that I have reduced. Two thirds of thefe 
obfervations had not even the fame ftars obferved at Greenwich 
and York ; and yet none of the refults, except a doubtful one, 
differ 
