162 
MINUTES OF PROCEEDINGS OF 
target; tlie wliole face is then coated with shellac, and covered over with 
silk, and afterwards given two or three coats of shellac, this insulates the pins 
perfectly. Two little double pressure screws insulated in ebonite are inserted 
in the frame. When the targets are required for use, the wire is stretched 
across them by means of the pins, a short piece being left at each end. The 
targets are then hung on the frames, and the ends of the wire put in com¬ 
munication with the double pressure screws; if these screws are also placed in 
communication with the main wires, the current will circulate through the wire 
on the target. When the wires of a target have been broken by the passage 
of a shot, it is detached from the frame, and a fresh target substituted. 
25. Several methods of construction have been adopted with regard to 
these frame targets, and the last seems to have given as much satisfaction 
as any, and is much the cheapest, viz.: the frame is constructed of common 
deal, and the pins are formed of screws run through a little piece of gutta 
percha tubing. 
26. In order to ascertain the remaining velocity of projectiles, the fol¬ 
lowing arrangements have been made:— 
The line perpendicular to the hurter of the platform has been produced 
and carefully measured to over 1000 yds., all the measurements being 
horizontal. 
Different ranges have been established on this line at the several distances 
from the gun of 200, 400, 600, and 1000 yds. Upright posts are sunk in 
the ground at these different distances, the posts are about three feet 
high, and serve as supports for the movable posts to which the wire targets 
are hung. 
The targets used at these long distances are from 6 to 9 feet square. 
Thus, let us suppose the range to be 200 yds., or that it is required to 
estimate the velocity of the projectile at a point 600 ft. from the muzzle 
picket. 
The first pair of pickets are set at 540 ft. from the picket, one on each 
side of the perpendicular line and at about three feet from it, leaving there¬ 
fore about 6 ft. between the uprights. 
The second pair of posts are set in the same manner, at 120 ft. from the 
first pair, and, therefore, at 660 ft. from the picket; so that the middle 
point between both pairs is 600 ft. or 200 yds. from the picket, 
The other ranges are completed in the same manner. 
The space of 120 ft. may be reduced by placing other intermediate 
uprights. 
The wires are carried on posts in the ordinary manner to the 200 yds. 
range; after that the wires are laid under ground, being perfectly insulated 
with indian-rubber and tarred hemp. 
The cable for this purpose was made by Messrs Wells and Hall, of 
Mansfield Street, London, and has given much satisfaction. 
The cable passes through a station, opposite each range, in which there is 
a disconnecting apparatus; by this arrangement the wires in the cable can 
be put in communication with the target on any range down the line. The 
stations are formed of hollow cast-iron cylinders with screw caps. 
