Despite the fact that this weapon looks like a joke, I checked in the US patent database, and it turned out that it was not a prank - the shooting helmet was patented on May 16, 1916, the patent documents were filed on July 14, 1915.
Page from Pratt's patent.
Albert Bacon Pratt proposed a special helmet for military use with a built-in "pistol". The weapon is multiply charged, semi-automatic, the automation works by recoil of the shutter. The caliber is unfortunately not known. A special window is provided for the extraction of the shells in the helmet. To fire, you need to blow into the tube connected to the "pear" located at the trigger. When the shooter blows into the tube, the "pear" inflates and interacts with the trigger, a shot occurs. The compartment of the helmet with the "pistol" is separated from the shooter's head by a special "comforter" for safety. The sighting device is at eye level and is shown in the patent.
Modern reconstructions of Pratt's helmet.
The patent describes that the recoil does not cause inconvenience to the arrow, since a special spring is used to extinguish. Aiming is much faster than using a weapon with your hands, on an instinctive level. According to the inventor, the soldier reacts faster to danger by turning his head, and after a simple training he could hit the target. Modern sources say that the recoil when firing from the helmet could break the neck, but there is no data on the caliber used, so it is impossible to speak with confidence about the strongest recoil. In 2011, Pratt's shooting helmet was recreated on American television in an analogue program of the famous "legend destroyers" and it was clearly proved that it was possible to shoot in this way.
Of course, this invention can be attributed to weapons curiosities, but the inventor did not stop and patented a slightly modified version of the helmet in 1917. Aiming with the head with the ability to leave hands free did not give rest to the next generation of inventors - in 1953, a certain DE Salardi patented a submachine gun worn on the head.
How, in practice, it is possible to conduct automatic fire from a submachine gun mounted on the head is a mystery to me.
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