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THE VALUE OP A HIGH SITE FOR COAST 
ARTILLERY. 
BY 
MAJOR J. R. J. JOCELYN, R.A. 
“ On heights, less protection is needed, the guns cannot so easily be rushed by landing 
parties, their practice is better, their target is always larger, while they are difficult objects 
for a ship to hit.—” 
Col. J. B. Richardson, R.A. 
R. A. I. Proceedings, Jan. ’93. 
The following notation will be used throughout the paper, 
a—Height above sea-level of a given objective. 
b = Length, measured in the plane of the trajectory, of the same objective. 
e = Distance between the place where a certain shot, fired from a level site , strikes 
the water and the nearest point of the objective. 
e' or E' = Distances, similarly measured, in the case of certain shots fired from a 
high site. 
All these quantities are measured in the same units. 
R = Range in yards to the nearest point of the objective. 
h = Height in feet, above mean tide, of a given site. 
I — Length in yards of 50 per cent, zone as given in the Range Table of any gun. 
I' = Length in yards of same zone, when modified by influence of site. 
m=ratio depending on the amount of quadrant elevation, necessary to change 
the range by 100 yards, in the case of a low and high site, respectively. 
n = ratio of the longitudinal errors, which will just cause a certain objective to be 
missed, in the case of a low and high site, respectively. 
q = Angle of Quadrant Elevation, due to h and R. 
co = Angle of descent, due to the trajectory, as given in the range tables. 
0 = Angle of depression due to h and R. 
3 =Angle at which shot strikes, which angle, it is proposed to call the angle of 
arrival. Thus 3 = 0-f&>. 
Suffixes are used to connect certain of the above quantities with different values 
of h, thus 3 100 would mean the angle of arrival when A = 100, m m would mean that 
the ratio referred to a level site and one 100 feet high and so on. The gun is always 
supposed to be at 0 , and HR' is the mean tide level. 
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