CONSIDERATIONS ON THE SUBJECT OF TRAJECTORIES, 208 
angles being marked along IK. The sliding scale is placed at the 
required angle, and the curve corresponding to range is followed to its 
intersection with the sliding scale, which gives the required elevation 
in degrees. 
As a practical question, it is hoped that the above may afford a 
means of acquiring a general acquaintance with the effect of such con- 
ditions, which may be useful (partly to sportsmen) in firing down steep 
mountain sides. Also for firing at balloons, or machine-gun fire from 
the tops of ships. It appears to concern the relative value of howitzers 
and high velocity guns for mountain warfare, and might be a useful 
method of graduating sights for high site coast artillery mountings, in 
cases where the assumption of the rigidity of the trajectory might not 
be sufficiently accurate. 
