20 
MINUTES OF PROCEEDINGS OF 
can be dealt with in a structure possessing little more strength than would 
be required for statical support. Moreover greater durability to material 
may be anticipated under continued action, than is obtained with carriages 
on which recoil is stopped by friction alone. 
In the proposed arrangement the recoil is stopped without injurious 
strain by an arrangement of forces analogous to those which stop the 
rolling of a ship, where the gradual rising of the centre of gravity of the 
whole structure puts a limit to the movement in one direction. The curve of 
the elevators can be made to control the meta-centre, and express the same 
movement, with nearly the same results. 
Tig. 1 shews the general arrangement of a Moncrieff carriage for a 7-ton 
gun. It consists of three principal parts, viz.— 
The Carriage Proper, A; The Elevators, B; and The Platform, C. 
A "R 
~ and ^ shew the carriage and elevators near the loading position. 
It traverses on a central pivot and a single circular racer 14 ft. in 
diameter, and the platform is about 16 ft. 6 in. in length. A counterweight 
I), sufficient to balance the weight of the gun, is placed between the two 
elevators. 
In the firing position, the centre of gravity of counterweight, and the 
fulcrum, on which the elevators rest, are nearly coincident, and are both in 
nearly the same vertical plane as the trunnions of the gun. 
On the discharge of the piece the elevators roll backwards on the platform 
causing the gun to descend in a cycloidal curve, while at the same time the 
counterweight rises (at first with an increasing velocity). The centre of 
gravity of both the gun and the counterweight together, is also the centre 
of the circular part of the periphery of the elevators ; this being the portion 
on which the elevators first roll after firing, it follows, that the common 
centre of gravity of the gun and counterweight travels backwards in a 
horizontal plane. And as this circular part is about a quadrant, the 
detachment is enabled to work the gun for drill purposes, or to place it 
under cover, from the firing position, with ease, the whole structure being 
