90 
MINUTES OF PEOCEEDINGS OF 
As the front set of arcs have a less radius than the hind set, when the 
gun is raised or lowered they would have a shorter distance to go through 
than the latter. This proportion is regulated by the diameter and number 
of teeth in the pinions which work the arcs. In this case the proportion is 
as 5 to 8; and,, consequently, the front pinions have 10 teeth and a diameter 
of 5 in. while the hind set have 16 teeth and a diameter of 8 in. The front 
set of pinions are keyed on a shaft which goes through both brackets in 
front of the transom; on the outer ends of this shaft are worm-wheels 
16 inches in diameter. The hind set of pinions are not connected by a 
shaft but are each attached to a worm-wheel outside the bracket by a short 
shaft that works in the gmu-metal bearing before alluded to. 
The worm-wheels are worked by a shaft passing under the hind wheels 
and over the fore. This shaft has a right-hand screw worm, one inch pitch, 
for the hind wheel and a corresponding left-hand screw worm for the front 
wheel. These shafts are worked by a hand wheel at each end, 2 ft. in 
diameter. 
The whole of this machinery is geared together by the two side shafts 
and the shaft that connects the two front pinions. A compressor is fitted 
on each arc, which, when set up, takes the strain off the pinions. The 
degrees of elevation are marked on one of the w T orm-wheels, and the degrees 
of depression on one of the hind arcs. With a power of 30 lbs. applied to 
each hand wheel a weight of about 22,400 lbs. can be raised. 
I now propose to explain how the gun is attached to the arcs. On the 
insides of these arcs, and 4 in. above and below the axis of the gun when at 
point blank, solid pieces of wrought-iron are forged, 8 in. high, 4 in. wide, 
and projecting inside the bracket T5". 
The gun is prepared to receive these supports by having its trunnions 
cut off, and having coils of suitable thickness shrunk on, and slots cut in 
the sides of these coils to correspond with the supports on the arcs,—these 
slots being cut at distances from the muzzle of the gun corresponding to the 
radii of the arcs. These slots are cut through from the lower part of the 
coil to 4 in. above the plane of the axis of the bore, w r here 1*5 in. of metal is 
left to support the gun upon the projecting pieces on the arcs. 
The gun when required to be mounted is slung in the usual manner, care 
being taken to keep it horizontal, and is lowered on to the supports on the 
arcs, which have been previously laid at point blank. 
Owing to this carriage being altogether of a new construction, and in the 
absence of special machinery, much of the work had . to be done by hand, 
special tools had to be made, and new patterns prepared, so that it was not 
finished till early in Spring, when the gun was mounted, and without further 
fitting or alteration was easily worked by four men; and it pivoted exactly 
on the muzzle. 
The gun and carriage were first inspected in the Pattern Eoom by the 
Select Committee, when the gun was worked several times from extreme 
elevation to extreme depression, and it took 2 min. 35 sec. to raise the gun 
from 10° to point blank. The Committee on a subsequent occasion inspected 
the gun at the Proof Butt, when it was fired 10 rounds, with 16 lbs. of 
powder and solid 68-pr. shot. The carriage was not the least shaken, and 
the gun was worked quite as easily after the firing as before. The gun has 
now been ordered to Shoeburyness for a more extended trial. 
