The Works Of Messrs. Schneider And Co.

324 MESSES. SCHNEIDER AND CO.’S WORKS. of the charge from returning to the rear, when firing takes place. V arnish and isolating substances are placed between the rod and the tube ; the rod is held in the rear hy a plug inserted in the bottom of the tube. The platinum wire, the incandescence of which insures firing, goes through a special composition placed in front of the tube, directly above the relay of powder. The wire is fixecl in the top end of the rod. The working of these tubes is easily seen by reference to Fig. 1042. FUSES AND DETONATORS. The Schneider-Canet fuses may be classified under three headmgs, namely, percussion fuses, double-acting fuses, and detonators. Each kind contains a whole series of distinct types, which correspond to the calibres of the guns and the dass of projectiles fired. A specirnen of each will be chosen for description. Percussion Fuses.—The Schneider-Canet patent per- cussion fuses are characterised by a double safety device, are held in place by their springs, and remain in the position shown in the illustration. When the projectile is fired, the striker tends, through, inertia, to remain back and presses down its spring, while the flange presses out the branches of the catch-spring ; these prcvent the striker from resuming its former position. The fuse is thus ready foi acting. When. the projectile strikes, the nipple is cliiven forward by inertia; it presses clown its spring, and the priming by coming in contact with the striker, gets inflamed and fires the powder inside the projectile. Double-Acting Fuses.—The Schneider-Canet double- acting fuses are of two principal patterns : a. Ring fuses, containing: the body, the two burning rings, the head and timing ring, the concussion device, and the percussion device. The body of the fuse is of brass, threaded at the lower parts, for screwing in the head of the projectile. The concussion device is contained in a threaded plug, which screws in the eye of the fuse. Each burning ring is made at its lower part with a which renders impossible the working of the interiør parts until the projectile has left the gun. The principal parts of this fuse are shown in Fig. 1043. The fuse contains : a. The body ending in a head, the outside shape of which dépends partly upon the shape of the head of the projectile. It is made with two threaded parts, one for fixmg the fuse in the projectile; the other, the inside threaded part, for holding the percussion plug : b. A slot through which the fire of the igniting charge is transmitted to tlie bursting charge of the projectile. c. The percussion-piece holder, closed by a screwecl plug, and comprising a threaded piece which ends in an extension of small diameter; it contains the striker which is constantly maintained at the lower part of its recess by a spiral spring. A catch-spring is placecl in the same recess. d. The cylindrical nipple contained in the fuse is constantly held clown by a spring; it carries the fulminate priming and a little quantity of powder. So long as the projectile has not undergone the shock caused by tlie firing of the gun, the striker and nipple Spiral Fuse. Detonators for Shells Charged with “ Schneiclerite.” circular recess, which is filled with a special powder ; the top ring is held fast by a rib, the lower ring alone being inoveable. The concussion device serves to tire the special powder when the projectile is fired from the gun. It consists of a striker and a primer, which are held apart by a spring. The percussion device consists of a nipple- seat with primer, placed in the lower part of the fuse, and of a iiipple screwecl above it, and in which is held the percussion striker. Charged vents are cut round the percussion piece, which establish a communication between the fusing device and the interiør of the projectile (Fig. 1044). Two conditions are to be considered in the working of these fuses : 1. Time Firing.—When the projectile is fired from the gun, the concussion piece is driven by inertia on its primer ; the powder is fired first in the top ring, and follows in the lower ring, the charge in the projectile getting fired through tlie slots cut in the fuse. 2. Percussion Firing.—For percussion firing, the move- able ring is turned so that it masks the vent which