High Quality Content by WIKIPEDIA articles! The QF 1 pounder universally known as the pom-pom, was an early 37 mm British autocannon. It was used by several countries initially as an infantry gun and later as a light anti-aircraft gun. It was originally designed in the late 1880s by Hiram Maxim as an enlarged version of the Maxim machine gun. Its longer range necessitated exploding projectiles to judge range, which in turn dictated a shell weight of at least 400 grams (0.88 lb), as that was the lightest exploding shell allowed under the St. Petersburg Declaration of 1868 and reaffirmed in the Hague Convention of 1899. Early versions were sold under the Maxim-Nordenfelt label, whereas versions in British service (i.e. from 1900) were labelled Vickers, Sons and Maxim (VSM) as Vickers had bought out Maxim-Nordenfelt in 1897. They are all effectively the same gun.