
430 APPENDICES 

some little practice, however, the observer will find an ordinary pocket- 
compass quite good enough for all his requirements. 
In the combined compass and clinometer here illustrated a pendulum 
hangs perpendicularly from the central point which carries the needle, 
and indicates the number of degrees the straight-edge or base, attached 
to the side, deviates from the horizontal. In the illustration the base 
being level, the pendulum points to zero. One advantage of this little 
instrument is that the straight-edge can be applied either to the upper 
or under side of a bed. Or if we are taking the angle of dip from a little 
distance, and holding the instrument between the eye and the angle to be 
measured, it is obviously immaterial whether the straight-edge occupies 
the position shown in the illustration or is inverted. 
