2 
A MANUAL FOR NORTHERN WOODSMEN 
The needle in compasses used for surveying purposes is 
commonly between four and six inches in length. It rests 
by a jeweled bearing at its center upon a steel pivot screwed 
into the compass plate, and, turning freely in the horizon¬ 
tal plane, its ends traverse the graduated circle. The plane 
of the sights passes through the center of the circle, and 
cuts its circumference at two points marked N and S, 
known as the north and south points of the instrument. 
From these points the graduation of the circle runs 90° in 
each direction to the points marked E and W. These 
Plain Surveyor’s Compass 
points on the face of the surveyor’s compass are reversed 
from their natural position for convenience in reading 
bearings. 
In using the compass, point the north end of the 
circle forward along the line and read from the north 
end of the needle. 
A compass bearing is the direction from the observer at 
