The Works Of Messrs. Schneider And Co.

332 MESSES. SCHNEIDER AND CO.’S WORKS. top floorings direct above the sectors in course of érect- ion, which would have much simplifiée! the work. Con- sequently, it was necessary to have recourse to the large trucks that travelled on the top floorings and raiseel all the pieces required for tlie framing with the help of smaller trucks, the track of which was per- pendicular to that of the large ones. These trucks worked in conjunetion with other small movable trucks, to which were suspended the counterweight boxes. Three motions could, therefore, be given to the pieces, namely, a vertical or rising action ; a motion of translation in the direction of the radius of the building, produced by the displaceinent of the large truck on the traveller ; and a motion of trans- lation perpendicular to the preceding one, given by the displacement of the small truck with regard to the large one. For insuring safety, all the manœuvres were executed from the Hoor level, with the help of a steam winch ; with this arrangement the foreman had all his men well in hånd, and all dangers that usually surround work done at great heights were done away with. The only men who were compelled to work on the top parts of the scaffoldings were those entrusted with the putting together of the varions parts of the building. The winch consistée! of two drums, round which passée! the lifting cables, and of two chain wheels on which turned the translation chains ; with the help of disengaging levers the two drums and two wheels could be made to turn together or separately. Each half of the winch, containing one clruni and one chain wheel, serveel one side of the building, namely, one of the travellers and its mechanisms. Lifting was effeeteel by a steel cable which rolied round the winch drum, and ended at a hxed point on the end of the top flooring of the traveller. The return pulleys, which led the cable from the drum to the fixed point, were so arrangée! as not to interfère with the displaceinent of the traveller ; moreover, during the translation of the trucks, the cable did not vary in length, so that the hook from which tlie charge was suspended remained at the same height. This result was obtained in the following manner : The lifting cable on leaving the drum of the winch passeel on a pivoting pulley f (Fig. 1070, Plate CLXX.), the groove of which always followed tlie varying direction of the cable during its rolling up on the whole length of the drum ; the cable then rose vertically, and passed on a pivoting pulley placecl on the top flooring of the central column, from there on another pivoting pulley placed under the traveller C, then on a fixed pulley, from which it took up a horizontal position ; it tlien engagêd a series of other pulleys up to p, where it was fixed. The motion of translation of the truck D was given by an entliess chain that turned on the chain wheel of the winch : it was also guideel by a series of pulleys. The smaller trucks F and G were worked by hånd. The .scaffoldings B and travellers C were shifted by hånd, by acting with crowbars under the carrying roller ; the extrem© positions takßii up by 6ach of the travellers formed an angle of 150 deg. ; or, in other words, each one turned through half the circumference, less the ares of two sectors of 15 deg. each. The brief description, with the illustrations, will give an idea of the numerous conditions that had to be fulfiDed, and of the way in which Messrs. Schneider and Co. carried out the work with safety, rapidity, and economy. A brief notice of the principal exhibits in this remarkable building will find a fitting place here. ORDNANCE. Naval artillery is represented by a practieally complété series of quick-firing guns 37 millimétrés (1.456 in.), 47 millimétrés (1.850 in.), 10 centimètres (3.937 in.), 12 centimetres (4.724 in.), 15 centimetres (5.905 in.), 20 centimètres (7.874 in.), and 24 centimetres (9.449 in.) in calibre. Ail these guns are of recent patterns, and are remarkable by their power and the ease with which they are worked. With the exception of those of 20 and 24 centimetres, they have all been described in this volume, and the only feature to be noted in passing is that these large-calibre guns are fitted with devices that insure rapid firing by one gunner, who can easily follow an aim moving at a 35-knot speed at a distance of 500 metres. These guns are shown fitted with three types of breech-blocks, namely : those of 37 and 47-millimetre calibre have an extra rapid-working, concentric-threaded block; those from 10 centimètres to 20 centimetres in calibre are fitted with a cylindrical breech-bloek, which is opened by one action of the lever ; for the larger calibre guns, a type of which would be the 24-centimetre quick-firing gun, the breech-block is cylindrical also, but it is worked by means of a crank placed on the side. Three turns of tlie crank are sufficient to open or to close the breech. All the breech-blocks are fitted with safety devices against prématuré and hanging fire ; and they are held fast when open by a special device. The Pavilion contains also a naval turret complété for a 24-centimetre gun, with the necessary mechanism for working it by band or by electricity ; also two quick- firing naval howitzers, 15 and 24 centimètres in calibre, firing shells charged with high explosives, for the attaek of armoured decks. These two howitzers are of a quite new type ; they contain very interesting devices—amongst others, an independent sight-line on the Schneider-Canet system. These varions guns, the howitzers included, would be equally well suited for coast defence. Field Artillery is represented by a whole series of guns, one group of which illustrâtes the varions transfor- mations of tlie quick-firing Schneider-Canet guns, dealt with at great length already in these columns. Among these are the following : A quick-firing gun, 1893 pattern, on carriage with hydraulic recoil cylinder and spring recuperator, elastic trail-spade, with india-rubber washers.