THE ROYAL ARTILLERY INSTITUTION. 
257 
The compressors for this carriage (Fig. 13) serve a twofold purpose, 
namely, the usual one of controlling the recoil, and the other of tying the 
carriage securely down upon the slide; they consist of plates hinged to the 
bottom of the bracket, with a screw at their upper ends, working in a female 
thread against the face of the other, their lower ends are fitted with hanging 
plates, to grip the wooden fittings of the platform, which are slightly tapered 
towards the lower edge, so that the action of these compressors, when their 
upper ends are forced outwards, will be not only to grip the wood on the 
sides of the slide, but also to bring the bottom of the carriage and top of 
the slide into closest possible contact. 
The arrangement for compressing the cradle to the main carriage was 
difficult to manage, as the only available space where the compressors could 
act on the cradle at all degrees of elevation and depression is occupied by 
the pinion and toothed wheels; the only way I could think of to get over 
this dilemma, was to make the compressors moveable. Their own weight 
keeps them in place when the gun is fired at elevation, and when fired at 
depression a stop on the bottom of each girder raises them to their proper 
position; they act on the cradle and carriage by jamming a small bevelled 
plate attached to the eccentric lever of the compressor against a similar 
bevelled plate fixed to the girder, and so tying the cradle to the side plates, 
by which means the teeth of the pinions and racks are relieved from the full 
force of the concussion arising from the discharge of the gun. 
I have now brought you to the point where this system is at present. 
I consider it as yet quite in its infancy, and have no doubt great improve¬ 
ments will be made in it. I do not see why, with proper management, steam 
power, hydraulic pressure, or compressed air, might not be brought to bear 
their part in lifting very heavy guns mounted on this principle; but 
whatever progress may be made in the working of this system, I do not 
think the fundamental principle of pivoting the muzzle by working the gun 
on arcs moving in the direction of the circumferences of concentric circles 
due to their common centre at the muzzle, will be much improved upon* 
I hope you will not consider that I am wandering from my text, if in con¬ 
nection with this subject I venture to say a few words on the mounting of 
our very heavy guns. It is my opinion—and I know that opinion to be 
shared by numbers of our most experienced officers of artillery—that all 
guns of 12-tons and upwards, whether for land or sea service, should be 
mounted in revolving turrets or cupolas. It is surely a pity to confine the 
range of these powerful guns to the limited angle of training to be obtained 
in any port or embrasure; whereas a gun mounted in a turret is completely 
protected, and, at the same time, has an unlimited range and field of view. 
This is the only method of mounting a gun that combines these two con¬ 
ditions. Two guns mounted side by side in a turret would be quite equal 
to six mounted in any other way. It is also my opinion that no gun heavier 
than 12 tons ought to be mounted on board ship, either in turrets or at 
broadside. I do not say for a moment that a 22-ton gun could not be 
worked in a turret in tolerably smooth water, on the contrary, nothing would 
be easier, and if the gun could be a fixture, like the engine or boilers, there 
would be little danger; but, unfortunately, to be useful, a gun must be 
moveable, and the only way to secure it in rough weather is by chains and 
