The Works Of Messrs. Schneider And Co.

200 MESSES. SCHNEIDER AND CO.’S WORKS. fired fuse being ejected automatically ; the whole of the device is placed in the breech-block. All the pieces are so arrangée! that they can be titted together separately from the gun, so as to form a whole block, which can be placed on the end of the movable head shank before attaching the lever, the latter holding the whole mechanism in place. The gun is absolutely safe against prématuré fire, for the action of opening the breech causes the automatic éjection of the fuse, whether it be fired or not ; and as long as the breech is not closed, it is impossible to introduce a fresh fuse in the vent, or to set the striker. The firing mechanism consists of a fuse-cover, a fuse-cover support, a key for the working of the fuse-cover, a per- cussion frame, with main-spring and needle ; a trigger, and an extractor. The breech is opened by pressing on the lever handle ; this causes the clutch to leave the socket made in the gun, the lever is then turned a quarter round to the right, dis- engaging the breech-screw. In this action the working key driven by the breech-block, and bearing on the breech- block support, turns round on its centre and lifts the fuse-cover which acts on the heel of the extractor, thus forcing it to eject the fuse, When the breech-block is disengaged, the working key bears on the block support, preventing all action of the firing mechanism. On drawing the breech-block out of the breech, the key is withdrawn also, but is prevented from turning owing to its heel ; the varions parts keep their relative positions, and render the introduction of a fresb fuse impos- sible, thus insuring complété safety. To close the breech, the above actions are repeated inversely. When the breech-block is completely screwed home, the key, under the action of the fixed handle, returns into position with the fuse-cover and frame. The fuse can then be placed in the vent after raising the fuse-cover. Firing is effeeted by means of a line attachée! to the trigger-lever. The percussion frame, on being drawn back, presses on the main spring which bears on the trigger-return device; after a certain travel, the frame is released, the spring driving it on the fuse. In case of a missfire, it suffices to pull again on the line to produce another percussion action. 3. ONE-MOTION BREECH OPENING MECHANISM. The Schneider-Canet guns were the first to be titteel with this type of screw breech mechanism ; they were quick-firing guns of 57 millimétrés (2.244 in.), 65 milli- métrés (2.559 in.), 10 centimetres (3.937 in.), 12 centi- metres, (4.724 in.), and 15 centimetres (5.905 in.) in calibre- From the commencement, the details of the various types of Schneider-Canet guns, designed with a view to obtain rapid firing, did not refer chiefly to the various parts of the carriage, but to the breech mechanism. The principal considérations which served as a basis in the calculation of this all-important part were the following : a. The réduction to a minimum of the necessary operations for opening, closing, and firing. b. Complété safety afforded to the personnel, so that the attention of the men serving the gun might be concen- tratecl upon the rapid manœuvres required ; and this state of safety results from, (1) the automatic succession in the positions of the breech-block, which does away with all hésitation as regards the order in which the various actions should be effeeted ; and, (2) providing safety devices against prématuré fire, hanging fire, and accidentai opening of the breech. c. The possibility of using indifferently a plastie obturator or a metallic cartridge-case, and electric or percussion firing devices. d. Réduction in the effort necessary to effect th& complété opening of the breech. The first type of Schneider-Canet one-action breech mechanism fulfilled all these conditions, and its appearance in the service proved a great success. Düring the early period, and up to the present date, it has undergone-—as has, in faet, the whole of the material — successive improveinents in the details of the mechanism, the first principle of the system not having been modified. We have seen that the design of the Schneider- Canet guns of high power, and great length of bore, was very much criticised in the first instance. It was the same with this new type of breech. When it first appeared its value was somewhat strongly disputed, especially by those works which had not yet then departed from the ordinary screw breech mechanism, that required three distinct actions in opening. As soon, however, as the results of trials made with this new breech mechanism were known, the arguments against it lost in intensity ; and the principle of opening the breech by one single action of the lever in a horizontal plane, was reproduced and applied by various foreign makers more or less successfully. At the present time the advantages of this type of breech are no longer disputed, and several firms who had criticised it the loudest, use—for every medium-calibre quick-firing gun they build—a breech-closing mechanism that works with a single action of the hand-lever. We sliall now proceed to describe briefly a few of the principal examples of this type of mechanism, following, as far as practicable, the chronological order of their adoption in service. Cylindrical Breech-Screw, with Repeat-Firing Action (Figs. 664 to 668).—This consists principally of the breech- block, the breech-block support, and the firing device. The breech-block is cylindrical, with four threaded | parts and four interruptions ; it is arrangée! for firing with metallic cartridge-cases, and is provided with two claws in front, which form extractors, and which are so disposed as to take hold of the cartridge-case flange, and withdraw it gradually during the opening of the breech. It is pro- vided in the rear with a tootbed sector, in tho continuation of which is a longitudinal hollow rack, inside the breech-