THE EOYAL ARTILLERY INSTITUTION. 
161 
sufficient motion of the breech to allow of elevation and depression ; 
but the large one has the advantage of causing the muzzle to dip after 
firing. This dipping would be useful in allowing the muzzle to hide 
itself behind a shield or counterscarp, where it would remain sheltered 
during loading and running up, and need only be exposed at the instant 
of firing. Another shield or turret could be placed about the position 
of the trunnions, so as to protect the most vulnerable parts in rear. 
The model is designed for a 15-inch gun, and with some alterations, 
for greater convenience, and to suit the new powder, it represents a 
very powerful gun firing 200 lbs. of powder, and a projectile of 1200 lbs. 
The body of the gun could be made wholly of coiled iron, with the 
usual steel tube; or, if the suggestions I have made could be carried 
out, it might have a wrought-iron coiled barrel, and a second course, or 
a second and third course of steel, in the region of the powder-chamber. 
It would weigh about 40 tons. The breech would be almost wholly 
of cast-iron, with a wrought-iron hoop to support the trunnions and 
the plug of steel, and would weigh about 30 tons. The total weight 
of the gun would, therefore, be 70 tons, and this is about one-sixth 
heavier than the proportion of gun to shot, if we consider the present 
service guns of smaller calibre; but it would probably not be more 
than the proportion which would be necessary if the present patterns 
were extended to such a heavy gun. At all events, any excess of 
weight would be more than counter-balanced by its being divided into 
two, and by having so large a proportion of the material of cast-iron. 
I am doubtful, however, if a gun of this size could be made to stand on 
any of the present patterns, and it is for this reason I have chosen this 
particular size, though it is impossible to say to what extent the modi¬ 
fication of the pressure of gunpowder may extend the limits to which 
any pattern of gun may be carried. But if, on any of the present 
systems, a 15-inch gun can be made, I am confident that, on this 
system of mine, a 20-inch gun might be obtained, firing a 1-ton shot, 
with a breech-piece and barrel of 50 tons each. If Mr. Reed makes 
ships carrying 15 and 20-inch armour, both guns will be needed, for it 
will require 15 and 20-inch guns to pierce them. 
At the conclusion of the paper— 
The Chairman invited discussion, saying that Captain Morgan would 
be very happy to hear suggestions or answer questions on the subject 
of his gun. 
Captain Noble said that Captain Morgan had not explained how the 
gun was to be loaded. 
Captain Morgan said the projectile and ammunition would be lifted 
by a crane and inserted at the breech. There would be a space of 4 ft. 
when the breech was open. 
In answer to other questions, the lecturer showed by his model how 
he proposed to draw the breech-piece backwards and forwards. 
