Firing the Treeby rifle requires following a specific process. First, of course, each of the 14 chambers must be loaded with powder and ball, and a percussion cap placed on the firing nipple on each one. Once the weapon is all loaded, the lever on the barrel must be rotated up. The barrel is connected to the frame by way of a very coarse thread, so lifting the barrel lever pulls the barrel forward, away from the chamber. Next, the hammer is manually cocked, which rotates the chain of chambers and indexes one into position. Then the barrel lever is rotated back down, pulling the barrel in and sealing it against the chamber. Only now can the trigger be pulled, which fires the round currently sealed up to the barrel.
Only two of these high-capacity bad boys were ever made. For a complete photo gallery and more history about the Treeby Chain Gun head over to Forgotten Weapons toot sweet.