228 THE VALUE OF A HIGH SITE FOR COAST ARTILLERY. 
to prevent their being raised to a dangerous elevation. This is easy if 
the sites are high, it is difficult when they are low. 
Torpedo catchers of the “ Rattlesnake ” type often accompany a 
torpedo boat attack: they might possibly give a good account of a low 
site battery of Q.F. guns; they could not do them much harm if they 
were 100' or more, above the sea. 
In addition to this, all the other contingent advantages of the high 
site hold true with Q.F. guns almost to the same extent as with 
heavier ordnance. 
VIII. The Trajectory of the Q.F. Guns. 
If the trajectory in fig. 9 were correctly drawn and to scale, it 
would be possible, of course, to ascertain the difference between PT and 
PX by actual measurement: but from the flatness of the curve, it is 
not convenient to plot it, without exaggerating the ordinates. Tra¬ 
jectories plotted in this way can be utilized for measurements, by a 
construction for which I am indebted to Major P. A. MacMahon. 
F 
Fig. 11. 
