Designer: The Great Leon
Patent Number 1,500,507
Originally known as The Silent Weird Gun, Leon would use this illusion as part of an entire "scientific" act that would demonstrate the power of his new ray gun.1 He worked on the illusion for four years and finally premiered the illusion in Sep of 1925.
The illusion was constructed in his warehouse and the cannon itself ended up measuring 11 feet in length. Leon ended up using a Hollywood stunt woman named Lillian White for shooting out of the cannon.2
The effect was that the Ray Gun could project physical objects through solid barriers. Leon created a 4x7 ft steel wall with a wooden frame. The frame would have paper (signed by participants) that was tacked on either side of it, obscuring the steel wall. The assistant would be shot through the paper and steel, breaking the paper apart but passing harmlessly through the solid steel plate.3 The girl was fired from the cannon through the first paper but the wall and second paper were left in tact.
Photo Credit: Mike Caveney, Magical Publications
SOURCES
[1] Caveney, Mike. The Great Leon. 1987. Pasadena: Magical Publications. p. 84
[2] Ibid. p. 85
[3] Ibid. p. 89