4 i 6 Mr . Pigott’s Determination of 
Thus I have given a comparative view of the different methods 
I employed in fettling the longitude of our Obfervatory, which 
is in Bootham, about 400 or 500 yards N. W. of the JMinfter. 
The occultations and meridian tranfits of the moon’s limb, 
which make it 2f / j, or i° 6' 2 would have been quite 
fufficient ; but ft ill it is interefting and ufeful to know how far 
the others err. With refpeft to the eciipfes of the moon’s 
fpots, I think that method is in general too much neglected ; 
and that it might be relied on infinitely more, if certain cir- 
-cumftances were mutually attended to, 
1 ft, To be particular in fpecifying the clearnefs of the Iky ; 
for in hazy weather the refults are very erroneous. 
2dly, To chufe fuch fpots that are well defined, and leave 
no hefitation as to the part eclipfed. 
3d] y, That every obferver ftiould, as much as poffible, ufe 
telefcopes equally powerful ; at leaft let the magnifying powers 
be the fame. 
A principal objection may (till be urged, viz . the difficulty 
of diftinguifhing the true fhadow from the penumbra. Was 
this obviated, I believe, the refults would be more exa£t than from 
Jupiter’s firft fatellite : undoubtedly the fhadow appears better 
defined if magnified little ; but I am much inclined to think, 
that with high magnifying powers there is greater certainty of 
chufing the fame part of the fhadow, which perhaps is more 
than a fufficient compenfation for thelofs of diftindtnefs. 
■i \ 
Concerning the meridian obfervations of the moon’s limb. 
The advantages and precifion of this method for determining 
the difference of meridians is, as I have already faid, fo little 
fufpe&ed, 
