400 
7 C ITALIAN FIELD GUN. 
method of turning down the iron to a right angle is a great advance on 
the angle-iron and riveting all round in the English carriage. 
The bracket sides are parallel to each other for about one-half of their 
total length; they are there bent inwards, and meet between the jaws of 
the trail plate. The form of the trunnion seat is peculiar. The trun¬ 
nion, it should be stated, is not cylindrical but slightly tapered from 
shoulder to face ; the trunnion seat is of similar form, but “ freed ” 
below the trunnion, so that the lower surface of the trunnion is not in 
contact with the lower surface of the trunnion seat. The trunnion, in 
a cross section, bears at two points as near the horizontal diameter of 
the trunnion as possible, so that at the moment of recoil the bearing 
points shall be in, or as near as possible in the line representing the 
force of recoil. This ensures the gun and the carriage recoiling to¬ 
gether. This, perhaps, will be better understood by considering the 
reverse case. If the trunnion be supposed to lie very loosely in the 
trunnion seat, at the moment of firing the trunnion is driven back 
violently against the trunnion seat; the whole carriage then takes up 
the motion, after suffering the strain thus suddenly applied. If, on the 
other hand, the trunnion bear on only two points, in a cross section, 
and those two points are in the line of recoil, there is no intermediate 
stage between the recoil of the gun and that of the carriage. 
The bearing of the axle-arm in the pipe-box is arranged on the same 
principle. The clearance or difference of their diameters is very small 
(0*01 in.)* 
The wheel and its axle were imitated from some specimens sent from 
Woolwich to the Exhibition of 1864 in Paris; consequently they must 
have been, judging from the date, the original Madras-pattern wheels. 
The Italian form of that wheel and axle seems to have succeeded 
admirably, while the English attempts in the same direction can hardly 
be said to have done so. 
The length of the pipe-box in the clear is 7*4 ins. The inside dia¬ 
meter of the aperture is 2*254ins. and the outside 1*713in., with a 
length between these diameters of 7*2 ins. It is of hard bronze, and 
has oil channels cut internally which end in two circles at right angles 
to its axis at a short distance from the faces. 
The nave is of cast-iron in two pieces, one being a movable disk with 
a central hole which fits the taper of the fixed piece and leaves a 
distance between it and the circular flange of the fixed piece equal to 
the width of the shank of the spoke. The width of the nave is 7*2 ins. 
The gun-carriage axle is of iron. The body is cylindrical in the 
centre and tapers slightly towards the shoulder. There are no holes in 
it. The length of the arm in the clear is 8*27 ins., a length of 0*4 in. next 
the shoulder being parallel to the axis; the remainder is taper. The 
diameter at this shoulder is 2*24 ins.; while that of the body at this part, 
bulged out slightly to a trumpet shape, is 2*6 ins. On this is shrunk 
* It is stated by the best possible authority that the clearance between the axle-arm and the 
pipe-box is all towards the front of the gun-carriage, and that contact is thus ensured between the 
two surfaces towards the rear, and that at the moment of recoil there is no jerk in finding the 
bearing. How this is effected is not very clear* 
