Automatic revolver

An automatic revolver is a revolver that uses the energy of firing for cocking the hammer and revolving the cylinder, rather than using manual operations to perform these actions. Despite the name "automatic", such revolvers are actually "semi-automatic" as the gun will not continue shooting and the shooter still needs to manually actuate the trigger to discharge each shot.
Examples of genuine semi-automatic revolvers are extremely uncommon, and the term is more often applied to break-open revolvers with linkaged ejector that automatically empties the spent casings from the cylinder upon opening the breech.
History.
An automatic revolver was communicated to Moses Poole, a patent agent, in 1841. The exact identity of the inventor of this weapon is unknown but in all likelihood it was a Frenchman by the name of Philippe Mathieu, who patented, amongst several different types of revolver, an almost identical design two years prior. Another automatic revolver was communicated to British patent agent William Edward Newton by the Americans Mershon and Hollingsworth in 1854. Both of these weapons used clockwork as the power for achieving automatic operation. In 1863 a gas piston-operated revolver was designed by a Spanish gunsmith by the name of Orbea. The Webley-Fosbery Automatic Revolver was designed in 1895 and would go on to become the first commercial and best known automatic revolver.
Description.
A standard revolver is a manually operated weapon, using the action of cocking the hammer to advance the cylinder in a single-action, or the action of pulling the trigger to advance the cylinder and cock the hammer in a double-action. The idea behind an automatic revolver is to automate both actions, removing the need to manually cock the hammer between shots while retaining the lighter trigger pull of the single-action.
This is accomplished by use of a reciprocating slide on the upper part of the frame, the motion of which is used to rotate the cylinder and cock the hammer in much the same way as is used in the majority of semi-automatic pistol designs.