THE ROYAL ARTILLERY INSTITUTION. 
347 
The cast-iron shell in addition to the fuze-hole has a loading hole in 
the ogival part; further, the cavity of the shell is divided into two parts by 
a wrought-iron diaphragm with a central hole through it. 
The charge of the shrapnel shell is composed of the burster, 1*54 oz. of 
musketry powder, contained in the cavity AT; further, of 55 leaden balls, 
26J to the 1 lb., in the cavity above the diaphragm; melted sulphur is poured 
between the interstices of the bullets. The brass tube T } filled with powder 
communicates between the fuze and the bursting charge. 
The loading hole, through which the leaden balls and sulphur are intro¬ 
duced into the shell, is closed by a screw-plug after the shell is filled. 
The shrapnel fuze is BreithaupFs, with several important modifications ; 
its component parts are, the body of the fuze (Fig. 14, z) the plate s , with 
its composition ring, the cover d, and the vent v. 
At the bottom of the body of the fuze is a magazine filled with 
musketry powder; the magazine communicates with the above-mentioned 
composition ring by a vent filled with a quickmatch leader; the bottom 
of the magazine is closed with sheet brass. 
On the outer surface of the plate, into which the composition is com¬ 
pressed, is a scale of ranges between 330 and 1244 yards; the composition 
ring is primed with quick match, both being protected by tin-foil; on the 
upper surface of the plate are two studs fitting corresponding recesses in 
the cover. The vent v screws down the cover and composition plate to 
the body of the fuze; a spanner is used for slackening the nut, when 
adjusting the fuze. The cover further has two studs with holes in them, 
into these the forked ends of the spanner fit to turn the cover and plate. 
The fuze is marked “ 3-pr.” on the outside of the composition plate. 
The fuze screwed into the shell is capped with a paper and a linen cover 
over the former, the latter being steeped in pitch. Both are tied round 
with twine. 
The weight of the shrapnel shell filled and fuzed is 6*635 lbs. 
(c) Case shot . 
The case shot (Fig. 15) is a cylindrical sheet zinc cylinder with zinc cover 
and driving bottom plate; it is filled with thirty-four zinc balls, eleven to 
the 1 lb., and with melted sulphur to fill up the interstices. On the cover is 
a ring for facility in handling the shot. The case shot filled, weighs 
5*015 lbs. 
{cl) Lubrication of projectiles and canvas bags . 
The cylinders of the common and shrapnel shells and of the case shot 
are covered with a thin layer of a lubricant composed of melted tallow and 
olive oil; the object of this lubrication is to diminish the friction between 
the projectiles and the sides of the bore of the gun in loading, but chiefly to 
keep the residuum of the powder in a soft state to prevent excessive fouling 
in the bore. 
To protect all projectiles from injury, and at the same time to preserve 
the layer of lubricant, each projectile is put into a canvas bag closed with 
the same material. 
