COMBINED HAND LEVEL AND CLINOMETER 93 
For these uses a light and cheap form of the level, some¬ 
times called the architect’s level, costing about half as 
much as one adapted to railway work, is commonly 
sufficient. 
SECTION III 
COMBINED HAND LEVEL AND CLINOMETER 
A pocket instrument capable of a great variety of uses 
is shown in the accompanying figure. The eye is placed 
at a peep hole at the right end (a) of the main tube. 
The cross-wire is over ( b ) in the figure, and beside it, 
occupying half the orifice of the tube, is a mirror set at 
an angle of 45°. Directly over the wire and mirror is a 
spirit tube (c), shown inclined in the figure. It is fixed to 
the milled wheel ( d ) which turns it, and the graduated 
arm (e), which serves to set the bubble parallel to the 
line of sight of the instrument, or to read the angle of 
inclination between them. When the bubble is in the 
center of the tube, the mirror below reflects it side by 
side with the cross-wire back through the peep hole. 
This instrument is largely used by northwestern lum¬ 
bermen in laying out roads, locating dams, etc., and it 
ought to be in the outfit of every woodsman. To use it 
as a hand level the zeros of the graduated arm and the 
scale must first be set together. The observer then sights 
an object through the tube, which he brings to a level 
by the bubble reflected in the mirror. He may then place 
himself on a level with the object by sighting at it directly, 
