New York City, 1911. Syrian immigrant children playing in the lower Manhattan neighborhood known as "Little Syria" (also called the Syrian Quarter, it was a vibrant enclave along Washington Street near the Battery where thousands of Syrians, Armenians, Greeks, and others from Middle Eastern and Mediterranean communities lived).
In 1956, in one of the laboratories of the American Navy in Maryland, the idea of scientists Crozier and Hume was realized in the form of a 40-mm two-stage helium light gas cannon. Compression of the helium ejecting projectile occurred due to the explosion of a mixture of oxygen and hydrogen. The caliber of the projectile was 12.7 mm.