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MINUTES OF PROCEEDINGS OF 
much greater than at the point of the trail; because the axis of the 
trunnion holes lies vertically to the front of the axis of the axletree, 
and also the bearing of the elevating screw is nearer the axletree than 
to the point of the trail—in fact, because the vertical component, part 
of which acts at the trunnion holes and part at the bearing of the 
elevating screw, acts as a whole at some point intermediate between 
the two. 
Again, this being the position of the point of application, as it 
were, of the total vertical component, it is evident that the trail and 
brackets (as part of the trail) have to support the whole brunt of it, 
while the axletree has only to bear a part of that whole. If the vertical 
component act upwards, the resistances of the ground will not then be 
called into play, but the weight of the carriage acting downward at its 
centre of gravity will offer the resistance; the tendency being, as before 
said, to tear the carriage asunder. When the vertical component acts 
downwards, and the resistances of the ground are called into play, they 
will in general be less in total amount than the component itself, the 
excess of the latter being expended upon the ground. This excess 
will vary with the hardness of the ground, and the carriage will be 
saved according as the latter is more or less yielding. Just in the 
same manner, the ground, by its nature, will influence the recoil, and, as 
before mentioned, in so doing influence the amount of the horizontal 
component spent upon the carriage, and the portion transmitted to and 
expended upon the ground. 
In a similar manner, the slope of the ground to the front or rear, by 
influencing the recoil, affects the destructive effect upon the carriage. 
It only remains to be noticed, with regard to the force transmitted 
from the gun to the carriage, that in guns having the axis of the 
trunnions below the axis of the piece, other things equal, the blow 
upon the trail at the bearing of the elevating screw is more severe 
than in guns in which the axes intersect; because the impulse on the 
bottom of the bore, acting in the line of the axis, has a moment or 
twist round the axis of the trunnions. 
Carriages having a detached elevating screw are liable to a second 
and destructive blow upon the trail, from the breech of the gun and the 
screw falling back to their place, after the rebound of the trail from 
the ground has thrown them up. 
As regards serving the gun in action, it is to be observed that the 
carriage is admirably adapted for laying the gun; admitting of ready 
motion being given to the latter in a plane perpendicular to the axis 
of the trunnions and to the carriage itself, and therefore to the gun in a 
plane at right angles to the former. 
As to furnishing a stable carriage for the gun in action, the form 
adopted gives three points of support, the vertical through the centre of 
gravity falling between them, and hence a stable carriage. Hot only 
so, but a carriage that is stable when the gun is fired; as the axis of 
the gun lies in the vertical plane (the wheels being on the level) con¬ 
taining the centre of gravity of the system, while the rear point of 
support of the carriage is in the same plane, and at a sufficient distance 
from the centre of gravity. 
