Volley gun
The Ribauldequin was a medieval version of the volley gun. It had its barrels set up in parallel. This early version was first employed during the Hundred Years' War by the army of Edward III of England, in 1339. Later on, the late Swiss army employed it.
Bailey machine gun
The Bailey Machine Gun was a rapid-fire weapon developed in the late 19th century. It was a multiple barrel weapon similar to the much more commonly known Gatling gun, and was the first weapon of this type to be belt-fed. Although commonly referred to as the Bailey Machine Gun, it is technically not a machine gun since it is externally powered using a hand crank. However, rapid-fire weapons of this type are commonly referred to as machine guns, even though this usage of the term is technically incorrect.