Elisha Haydon Collier (1788–1856) of Boston, Massachusetts, invented a flintlock revolver around 1818. It is one of the earliest true revolvers, after the 1739's revolver of Iaumandreu from Manresa and 1702's of Rovira from Ripoll, exhibited in the Armouries of the Tower of London, in contrast to the earlier pepperboxes which were multi-barreled guns. Collier's revolver was not self rotating but it was self-priming: a compartment automatically released gunpowder into the pan when the hammer was cocked.