304 NEW FIELD CARRIAGE (IRON) FOR LONG-RANGE GUNS. 
The correctness of these considerations is fully proved by experience. 
The first carriage for the long-range 9-pr. was made without a buffer, 
upon the type of the Swiss carriage, and was furnished with a cylin¬ 
drical axletree 3*3 ins. in diameter, securely fixed by three straps to the 
brackets and to its middle point. At the end of 30 rounds fired with 
the 9-pr. the axletree broke, and was replaced by one still more solid, 
the body of which was square in section, of 4*04-in. side. This new axle- 
tree broke also after 10 rounds with the 9-pr. with a charge of 5*4 lbs. 
The carriage was then mounted on the ordinary field axletree strength¬ 
ened by tie-bars, but it broke at the end of 250 rounds; the rupture 
probably taking place from the bad quality of the iron. When the 
broken axletree was removed, it was discovered that all the bolt-holes 
connecting it with the carriage, had worked oval, and that all the bolts 
themselves were twisted and sheared. 
After this accident a buffer was fitted, and thus modified the carriage 
stood, without the least damage, 604 rounds from the ordinary 9-pr. 
and the heavy 4-pr., of which 80 were fired with the trail sunk in the 
ground, so as to stop all recoil. At the end of the firing, the trail was 
buried almost up to the elevating gear. 
On this model a new carriage was made, which stood without damage 
1190 rounds from the long-range 4-pr. After this first trial, the axle- 
tree was replaced by a stronger one, in order to be strong enough for 
the 9-pr. The carriage with axletree thus strengthened received then 
a long-range 9-pr., with a chamber enlarged, in order to obtain a muzzle 
velocity of 1200 f.s. With this gun, 404 rounds were fired with a 
charge of 5’631bs. of large-grain powder, of which 100 rounds were at 
20°. The carriage stood this trial without damage. 
Two seats were then fitted, also fixed on buffers of india-rubber. 
Before this modification the seats had begun, at the end of 200 rounds, 
to show such damage that at the end of the trials of the carriage, they 
were nearly entirely detached. The seats fixed on buffers are not 
exposed to this danger. 
With the third carriage, 1600 rounds were fired with the long-range 
4-pr. The carriage, &c., stood this trial without damage. The excess 
of strength thus shown in the carriage allowed of a further improve¬ 
ment—viz., of fitting across the end of the trail a square plate, which 
fixes itself in the ground (see sketch), for the purpose of checking the 
recoil. This modification reduced, as a general rule, the sum of recoils 
of 20 rounds to 7 paces ; that is to say, that at the end of 20 rounds, 
the recoil had only driven the gun back 7 paces from the spot it occu¬ 
pied before firing. This diminution of the extent of the recoil has the 
great advantage of facilitating and accelerating the working of the 
gun. 
The trial endured with the 9-pr., with a velocity of 1200 f.s., showed 
that that velocity could be increased still more, as also could that of 
the light 4-pr. 
We find in Table B that the velocity of recoil of the system is 18 ft. 
per second for the long-range 9-pr. with a velocity of 1200 f.s., while 
it is only 17*3 f.s. for the light 4-pr. with a velocity of 1404 f.s.; while 
the 9-pr. weighs 12*2 cwt., and the light 4-pr. only weighs 6*43 cwt. 
