100 ADJUSTABLE POINTERS. 
though in that case it would be better to have a swinging pointer, thus, 
giving a larger arc for the graduation of corrections. 
Fig. 3. 
Front HLEVATION. 
Note.—As a general rule for guns far apart and large corrections the swinging pointer will be 
most suitable. For small intervals and corrections the revolving pointer. 
The swinging pointer can be made to any desired degree of accuracy 
by increasing the length of the upper arm. 
Now taking the other correction for extreme angles of training it 
will be easiest to have these two ares for corrections one above the 
other, thus :— 
Fie 4, 
with a vertically sliding pointer moving up and down in a collar on the 
