Dr. Charles Hutton on 
278 
the visible effects may thus be nearly equal, by the reciprocal 
balancing between magnitude and distance. Hence the visi- 
ble effect of the mountain, is that of the small angle of eleven 
or twelve seconds, by which the plummet is drawn aside 
from the perpendicular ; thereby showing that the attraction 
of the earth, on the plummet, is to that of the mountain on 
it, as radius is to the tangent of those seconds ; while, in the 
other experiment, the small pendulous balls are drawn aside 
by the large ones the space of between one-seventh and two- 
thirds of an inch ; the distance of each ball from the middle 
of their connecting rod, being a little more than thirty-six 
inches. The first or immediate small results of the two 
experiments, thus appearing so far to be about equally fa- 
vourable, it will be necessary to examine the circumstances 
of each of them separately, that we may be able to judge 
more particularly of their merits; and, first, of the Schehal- 
lien experiment. 
This experiment, it is well known, was conducted by the 
late Astronomer Royal, Dr. Maskelyne, than whom a more 
correct, faithful, and experienced individual probably never 
existed. The account of his measures and observations, 
taken in conducting it, is minutely detailed in the Philoso- 
phical Transactions of the year 1775, or in my edition of the 
Transactions, vol. xiii, page 702 ; where all the instruments 
and operations are particularly described, in the most plain 
and satisfactory manner. The principal instrument was the 
ten foot zenith sector ; with which the meridian zenith dis- 
tances of forty-three stars by three-hundred and thirty-seven 
observations, were carefully taken, both on the north and 
south sides of the mountain. The medium of all these, with 
