the mean Denjity of the Earth. 725 
lections, that an example of it is unneceffary : and the 
few horizontal fedtions need no computation, but only an 
allowance for the height of the theodolite. 
In the following abftradl of the refults of the compu- 
tation of the fedtions, the firfl column contains the num- 
ber of the pole, the lecond and third the vertical and 
horizontal angles, and the laft the difference of altitude in 
feet, between the foot of each pole and the point from 
whence the vertical angles were obferved, after making 
the allowance for the height of the theodolite above the ' 
ground. At the end of this abftradt is a plate of the 
figures referring to the number of the fedtion, {hewing 
the direction in which it was carried,, with the degrees 
and minutes in the angle formed by it and the bafe. 
line. 
S E C- 
