442 
MINUTES OF PROCEEDINGS OF 
evident that the elements of the shooting of the piece with various 
charges must be known, to enable the artilleryman to give an answer 
to this question. For this purpose a series of tables of fire for each 
piece is thus constructed :— 
The gun is fired with its service charge at upright wooden targets 
at 500, 1000, and 1500 yds.; further, practice is made with such eleva¬ 
tions as shall give ranges of about 2000, 2500, 3000, and 4000 yds., 
the ranges being measured on the plane. At the shorter ranges fifteen 
rounds are fired at each elevation, exclusive of trial shots; at the longer 
ranges twenty rounds are fired, as the disturbing influences acting on the 
projectile increase with the range. The positions of the mean points 
of impact are calculated, the elevations being corrected so as to bring 
them to what they would have been had the ranges been measured on 
a horizontal plane through the muzzle of the gun. 
In Prussia no notice was taken of the angle through which the gun 
jumped on discharge; in Russia it seems to have been taken into 
account, the angles of elevation being corrected accordingly. 
The positions of the seven mean points of impact are laid down on 
lattice-paper, the angles of elevation being taken as ordinates and the 
ranges as abscissae; the origin being at the muzzle of the gun. A 
curved line is traced connecting the seven points as advantageously 
as possible with the origin; that is, if a continuous curve, starting 
from the origin, cannot pass through the seven points, it should leave 
as many points above it as below it. The elevations for intermediate 
ranges can now be read off at will. 
The gun is next fired with about the lowest charge with which it 
will fire with accuracy. For guns intended more especially for flat 
shooting, the charge is found to vary from 43 -th to -g-^th of the weight 
of the shell. Finally, it is fired with two charges equidistant between 
the service and the lowest charges. The elevations are such as will 
give ranges of about 500, 1000, and 1500 yds.; fifteen rounds being 
fired at each elevation. If the angles of elevation and projection are 
found to be the same, no correction is required beyond that due to the 
height of the gun above the plane, as in the previous case. The points 
are plotted on lattice-paper as before. The elevations for intermediate 
ranges can be found by inspection. 
The elevations for the fundamental charges are used to obtain eleva¬ 
tions for all intermediate charges as follows :—For four fixed ranges of 
500, 1000, 1500, and 2000 yds., four separate curves are struck, 
elevation and charge being taken as abscissa and ordinate. Having 
thus got four elevations giving fixed ranges for any charge we please 
between the lowest and the service charge, a curve is traced for each 
proposed charge, elevation and range being taken as ordinate and 
abscissa. 
In the Russian tables there are fifteen or sixteen charges for each 
gun; the increase of charge being at first one-half what it is as the 
service charge is approached. Thus, on the same sheet of lattice-paper 
the whole of the fifteen curves are traced/and from these curves fifteen 
tables are made out of the shooting of each gun. 
The following is a specimen of the Russian tables :— 
