When first bringing
the gun into action, the barrel is brought into the preliminary
position by manually compressing the air or spring by means of a
lever. Thereafter the gun works automatically. When the gun is
fired the barrel is released and it flies forward. At a critical
point in its forward travel the charge is fired and the
projectile speeds on its way. The kick or recoil serves to
arrest the forward movement of the barrel and finally drives it
back again against the strong spring or cushion of compressed air
within the cylinder to its normal position, when it is ready for
the introduction of the next shell.
The outstanding feature of this system is that the projectile is
given a higher initial velocity than is possible with the barrel
held rigid at the moment of discharge, because the shell is
already travelling at the moment of firing.
The fixed anti-aircraft guns such as are stationed upon eminences
and buildings are of the quick firing type, the object being to
hurl a steady, con tinuous stream of missiles upon the swiftly
moving aeroplane. Some of the weapons throw a one-pound shell
and are closely similar to the pom-pom which proved so effective
during the South African war.
Pages:
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250