Elephant mounted with a M1895 Colt-Browning machine gun, WWI; ca. 1914-18.

The least they could have done was give the elephant some giant ear plugs.

A corporal aims a Colt M1895 atop a Sri Lankan Elephant.  The M1895 was developed by John Browning during the 1890s, it was a belt-fed, air cooled, gas operated machine gun.   As the weapon was air cooled it did not require the water cooling system used by the Maxim Gun, as a result it was much lighter weighing just 35 lbs.

The M1895 was lever actuated which meant that the gun was cocked by retracting the lever and once the first round was fired the propellant gas was tapped from a gas port several inches from the muzzle this gas pushed the lever down and swung it back towards the receiver to cock the gun for the next round.   If the gun’s tripod was set too low, or impeded by cover, then the lever would catch any obstruction, as a result it quickly became known as the ‘potato digger’ by troops.  There looks to be more than enough clearance on top of the elephant.

While there is historical precedent for the use of elephants in warfare for over 1000 years, used by the Persians, Alexander the Great, Indian Sultans, Siamese warriors who mounted Jingals (small guns often mounted on walls) on elephants well into the 1880s, and later by the British Army in India as pack animals capable of carrying mountain guns and supplies over difficult terrain.  Why the corporal is atop the elephant is a mystery but it was never a weapons platform adopted by the US Army.

(Source)