THE ROYAL ARTILLERY INSTITUTION. 
259 
they are fitted with worm wheel heads, and are operated upon by a shaft passing 
through the front of the carriage, fitted with the necessary worms and handwheels. 
The action of this compressor is to squeeze the T iron, which forms the top of the 
slide, between the bottom of the carriage and the girder, as in a vice, and as by 
this arrangement of screws and worm wheels, an enormous amount of pressure can 
be obtained, in fact, when the compressor is set up, the carriage may be said to form 
a part and portion of the slide, and be quite immovable in the roughest weather; 
and I know that the gun was fired when the ship was rolling 16° both ways, and 
was under perfect control, which was not’the case with the other guns on board. 
The running in and out gear for this carriage is fitted as follows :—A powerful/ 
winch is fixed in rear of the turret, and between the sides of the slide; in the fore 
part of the turret a pulley is fixed to the deck fitted with a set screw, an endless 
flat chain is passed round this pully and the barrel of the winch, it also passes 
through a slot in an iron bracket under the carriage, into which a strong iron plunger 
is fitted, so as to work up and down by means of a screw fitted with an elevating 
screw head; when the carriage is to be attached to the chain for running in or out 
a turn of the screw drives the plunger down between the links of the chain and 
fixes the carriage to it, and a turn the opposite way immediately releases it when 
required for firing. 
This carriage and slide were completed in November, 1865, and a 9" 12-ton gun 
was mounted and found to work perfectly. Tour men, with the hand wheels, raised 
the gun through an arc of 10° in five minutes ; and with winch handles, they raised 
it through an arc of 14'75° in four minutes ; twelve men with long winch handles, 
raised it 14'75° in two minutes and twenty seconds, it can be run down in two 
minutes. Tour men can easily alter the elevation one degree in twenty seconds. 
On the 27th November, 1865, the gun was mounted on its carriage and slide in 
front of the Proof Butt, Koyal Arsenal, for the purpose of firing ten rounds to test 
the strength of the carriage previous to shipping it on board the “ Prince Albert ** 
which was then lying in Woolwich Dockyard. There were present on the occasion 
Major-Greneral Warde, Kear-Admiral Caffin, Commodore Dunlop, the members of 
the Ordnance Select Committee, and a number of officers of both services. The 
charge was 40 lbs. of powder and a shell of 260 lbs. The result of the firing was 
as follows:— 
1st round, 2 men at the compressors, recoil 7 ft., breeching chain broke, owing to a 
faulty attachment to the carriage. 
2nd round, 4 men at compressors, recoil 6 feet. 
3rd a 5 n a n 4*9 « 
4th n 6 n " n 4*4 a 
I suspended the firing here in order to have the defects of the breeching made 
good, which was done by attaching it to the carriage with a swivel to secure an 
equal strain on each part of the chain. The firing was resumed on the 8 th of 
December with the following results :— 
5th round, 2 men at compressors, recoil 4 
// 
9 
6 th n 
2 a u 
n 4 
7th « 
2 n n 
// 4 
8* 
8th a 
1 it n 
n 4 
8* 
9 th n 
compressor slack. 
5 
2 
taut breeching, india-rubber rings on breeching, both compressed, 2 J inches. 
10th round, 1 man at compressor, 4' 8%", everything about the carriage, slide, compressor 
and breeching perfectly sound and in good order. 
