2 
The diagram of the velocity of recoil as demonstrated by Seberts’ velocimetre, 
shows that the force which urges the gun back during recoil, is subject to a series 
of oscillations, which, however, succeed each other so rapidly, that the force may 
be considered as continuous—the changes in the velocity of recoil, i.e. its alter¬ 
nate increase and decrease are due to the elastic reaction of the bore. 
It has been ascertained by this velocimetre that the velocity of recoil of a gun 
not provided with the apparatus we are discussing, increases up to a certain 
maximum which is reached soon after the projectile has left the bore. This 
maximum (in the gun experimented with i.e. 80 mm ) was about 4*1 m.s. (13’45 f.s.) 
and was reached in • 04" after the projectile had left the bore. When the same 
gun was fitted with the gas bridle (as we may appropriately term the apparatus) 
the velocimetre showed that the velocity of recoil at first increased, reached its 
maximum as the projectile left the bore, and then began to decrease. According 
to experiments made, the maximum velocity of recoil was 3*45 m.s. (1P32 f.s.) 
and was reached in less than *01" after the projectile had left the bore ; further, 
that *03'' or '04" after it had left the bore the velocity of recoil did not exceed 
2 m.s. (6'56 f.s.). . It was also ascertained that the initial velocity of the projec¬ 
tile increased from 476 m.s. (1561 f.s.) to 481 m.s. (1578 f.s.) which increase 
may be attributed to the action of the gas on the base of the projectile during its 
passage through the aperture in the cap. It may be dednced from this that the 
accuracy of the piece must infallibly have been increased. 
The gas thrown back by the Bridle causes some annoyance to the detachment: 
this inconvenience might be overcome by continuing the sides of the cap still 
further back and joining their inner ledge to the chase, or a fan (or screen) might 
be attached to the breech portion of the gun, which would serve as a shield. 
Such an arrangement applied to Quick Firing guns would render possible the use 
of larger calibres than those which have now been adopted for repelling torpedo 
attacks. 
The recoil of a 80 mm field gun provided with the ordinary recoil break, but 
without the Be Place “ gas bridle ” had, according to experiments made, a velo¬ 
city of 1-54 m.s. (5’05 f.s.), with the Be Place “bridle,” only *4 m.s. (P31 f.s.). 
Fig. 2 a . 
The similar apparatus invented by Signor Nottbeck (Fig. 2 a ) consists of a thin 
plate of metal C solidly united, in the way we shall describe, to the gun D , the 
plate has a central hole C, which gives passage to the projectile, and is furnished 
with a notch b which allows of the gun being laid by means of the foresight b. 
By means of the strong clamps B,B, the plate is attached to a collar (lit muff) A 
provided with a slot parallel to the axis of the piece, from which two other slots 
a t a, open at right angles—the foresight fits into one or other of these slots and 
thus fixes the apparatus. 
The mode of action is the same as in Be Place’s apparatus. The size of the 
plate C and its distance from the muzzle of the piece, as well as its strength, 
must be determined by experiment for each nature of gun or small-arm. 
