873 
Lithological Survey of Schehallien . 
quarter cylinder itself has been found = 53.3532, from which 
taking away .2534, there remains .53.0998 for the entire sum 
of the sines belonging to the quartz under the level of O in the 
north-west quarter of the mountain. 
In like manner the sum of the sines computed for the mica- 
ceous columns and parts of columns in the north-west quarter 
cylinder, is 23.0124, from which taking away 13.2806, the 
deficient or negative part, there remains 9.7318. The num- 
bers thus found being multiplied by £22, give the coefficients 
of O and M for the north-west quarter of the mountain below 
the level of O, and make its attraction = (2949.93) Q -J- 
(54°- 6 55) M. 
A similar computation being made for the quarter cylinder 
on the north-east of O, we have its attraction = (2974.299) 
Q -j- (577.98) M, to which adding their former attraction 
( 2 949-99) Q + (540-655) M, we have S— V, or the attrac- 
tion of the mountain on the north side of O, and under the 
level of O = (5924.289) O -j- (1 118.635) M. In like manner 
the attraction of the south-west quadrant deduced partly from 
the quarter cylinder, and partly from Dr. Hutton's calcula- 
tions = ( 1049,18) Q 4- ( 1813.66) M, and of the south-east 
— (1567.394) Q + (1052.129) M; the sum of which, or 
S' — V', gives (2616.574) O -f (2871.7,89) M; to be subtracted 
from the former, in order that we may have the total disturb- 
ing force of the part of the mountain below O, which is there- 
fore — (33°77t5) Q - (1753 !54) M. 
Lastly T, or the attraction of the part of the mountain above 
O (which is on the north), when computed from the sums 
of the sines of the elevation of the columns above O, as given 
