The revolver chambers are drilled out of solid iron, by a drilling machine or lathe, with a centrebit and an eccentric motion, which causes each barrel of the chamber-nest to become the centre in succession; while, by means of a slide, the motion can be made to suit either a large or small chamber. The recesses communicating with the lock and trigger are cut by reversing the chamber in the eccentric “chuck,” and using a different cutting-tool, while another alteration effects the drilling of the nipple holes. THE END R. CLAY, SON, AND TAYLOR, PRINTERS, BREAD STREET