448 
MINUTES OF PROCEEDINGS OF 
The Hotchkiss Revolver Cannon.* 
This is a species of mitrailleur meant to fire small percussion shells, 
weighing (when filled) 570 grammes—about lbs. 
In external appearance it much resembles a Gatling gun, but its 
mechanism is quite different. 
Six barrels of steel pass through two discs, secured to a shaft or 
axis which is capable of revolution in a rigid frame of wrought-iron. 
Underneath the system there is, as in the Gatling, an arrangement to 
allow of the gun pivoting for lateral spread, and also trunnions to 
allow of movement in a vertical plane. 
A spindle, with a worm at the interior end, and at right angles to 
the main shaft, gears with a pinion at breech end of the latter, so that 
by turning a handle on the other end of spindle, at the right side of 
the piece, the axis and barrels are made to rotate. 
The thread of the worm is an interrupted one, about one-half of 
each turn being at right angles to axis of spindle. The system does 
not therefore rotate during half of each turn, and in this half discharge 
takes place. 
There is only one lock, opposite to which each barrel is brought in 
turn. This lock consists merely of a striker and a strong spiral 
spring. 
The spring is compressed by a cam, as rotation proceeds; and when 
a barrel comes round so that its breech end fits against a piece of 
steel let into breech part of mechanism, the spring is released and the 
charge exploded. 
The full cartridges are pushed into, and the empty ones extracted 
from, the barrels by a plunger and extractor, secured respectively to 
the ends of two ratchet bars, which are caused to advance and retire 
by means of an arm with projecting pin secured to the end of the 
spindle which rotates the main shaft. 
This pin works in a slit-bar, fastened at its centre to the lower ratchet ; 
and so, with the assistance of a loose pinion gearing into both the 
ratchets, they are made to advance and retreat alternately as the handle 
goes round. 
When the ratchets are in their extreme positions, the slit-bar remains 
for an instant motionless. The pin does not act for that time > one side 
of the slit being cut out in a curve. The barrels are not rotating just 
at that moment, so the cartridge is in one case pushed in, and in the 
other withdrawn, as one ratchet or the other acts; 
* For the reasons given (pp. 425-6), it does not seem probable that a weapon of this description 
will be found to answer. Though firing shells, the latter would be too small to penetrate cover at 
any distance. Still, the idea is somewhat novel, as well as the mechanism, in which ratchet bars play 
a prominent part. 
