Courtesy of "Scientific American"
The Maxim Machine-gun Operated by the Energy of the Recoil
Courtesy of "Scientific American"
Colt Machine-gun partly broken away to show the Operating Mechanism
Gas from port A pushes down piston B, rocking lever C, which compresses coil-spring D. The cartridge fed into the gun by wheel E, is extracted by F, raised by G to breech H, and rammed in by bolt I. J, piston firing-hammer.
The French in particular used this type of mortar and the air-pump was used to compress the air that propelled the shell or aërial torpedo, or else the propelling charge was taken from a compressed-air tank. Carbon-dioxide, the gas used in soda-water, is commonly stored in tanks under high pressure and this gas was sometimes used in place of compressed air. When the gas in the tank was exhausted the latter could be recharged with air by using a hand-pump. Two or three hundred strokes of the pump would give a pressure of one hundred and twenty to one hundred and fifty pounds per inch, and would supply enough air to discharge a number of shell. The air was let into the barrel of the mortar in a single puff sufficient to launch the shell; then the tank was cut off at once, so that the air it contained would not escape and go to waste.
THE STOKES MORTAR
However, the most useful trench mortar developed during the war was invented by Wilfred Stokes, a British inventor. In this a comparatively slow-acting powder was used to propel the missile, and so a thin-walled barrel could be used. The light Stokes mortar can easily be carried over the shoulder by one man. It has two legs and the barrel itself serves as a third leg, and the mortar stands like a tripod. The two legs are adjustable, so that the barrel can be inclined to any desired angle. It took but a moment to set up the mortar for action in a trench or shell-hole.