ARMOUR AND ITS ATTACK BY ORDNANCE. 
99 
The whole structure of this mounting is balanced upon the pivot 
column, which moves up and down in the cone, and rests upon a lever, 
such as is shown in .Fig. 21, whose counter-weight balances the 
Fig. 21. 
mounting. The gun rests with its trunnions in a frame, sliding back¬ 
ward and forward in guides. Bolts, which hold the gun from recoil, 
enter grooves in these guides, and are connected with a lever, on which 
the seat of the gunner pointing the gun is made fast. When the bolts 
are drawn back the seat is raised, and when pushed forward it is 
lowered. The effect of firing is to press the armoured ring against 
the glacis armour, after which it recovers its position again immediately, 
owing to the situation of its centre of gravity. The glacis ring is of 
chilled-iron, resting on sheet-iron plates and girders. In the position 
of eclipse, the flatness of the dome causes the top of the mounting to 
be very difficult to see or to strike with artillery fire, and the roof or 
dome resting on the glacis ring, the impact of projectiles c&n produce 
very little injury to mounting or armour. 
