522 Mr. Cavendish's Experiments to determine 
equal to the difference between this and the extreme ; and, 
therefore, it seems very unlikely that the density of the earth 
should differ from 548 by so much as of the whole. 
Another objection, perhaps, may be made to these experi- 
ments, namely, that it is uncertain whether, in these small 
distances, the force of gravity follows exactly the same law as 
in greater distances. There is no reason, however, to think 
that any irregularity of this kind takes place, until the bodies 
come within the action of what is called the attraction of co- 
hesion, and which seems to extend only to very minute dis- 
tances. With a view to see whether the result could be affected 
by this attraction, I made the 9th, 10th, 11th, and 15th expe- 
riments, in which the balls were made to rest as close to the 
sides of the case as they could ; but there is no difference to be 
depended on, between the results under that circumstance, and 
when the balls are placed in any other part of the case. 
According to the experiments made by Dr. Maskelyne, 
on the attraction of the hill Schehallien, the density of the 
earth is 4-j times that of water ; which differs rather more 
from the preceding determination than 1 should have ex- 
pected. But I forbear entering into any consideration of 
which determination is most to be depended on, till I have exa- 
mined more carefully how much the preceding determination 
is affected by irregularities whose quantity I cannot measure. 
1 
