Friction Primer

In gunnery, consists of a short tube of metal inserted into a hole near the top of a larger tube, and soldered in that position. The short tube is lined with a composition made by mixing together one part of chlorate of pota a and two of sulphuret of antimony, formed into a paste with gum-water. A serrated wire pa es through the short tube and hole opposite to it in the side of the long one, the open end of the short tube being compre ed with nippers, and the wire at the end of the serrated part doubled under to prevent displacement. The other end of the wire is doubled and twisted by machinery. The long tube is filled with rifle-powder, its upper end being covered with shellac-varnish blackened with lamp-black, and its lower end closed with shoemaker’s wax and dipped into varnish. One great advantage of the friction tube is that it gives an enemy at night no clue to the position of a piece as does the lighted port-fire or slow-match.