The Works Of Messrs. Schneider And Co.

GUN TUBE TEMPERING PLANT. The plant for gun tempering consista of two vertical furnaces and a tank, placed in a large pit 14.500 metres (47 ft. 7 in.) long; 11 metres (36 ft.) wide; and 14.500 metres (47 ft. 7 in.) cleep. The large furnace is 18.300 metres (60 ft.) high ; it is provided with five tiers of lires, one above the other. The gases escape on the opposite side, through a series of openings with outlets in a flue built up the whole height of the furnace. The side of the furnace which is nearest to the pit opens out in one piece for admitting and removing the pieces. The tempering tank can therefore be reached with little delay, as the piece has not to be lifted out of the furnace. The opening 67 furnace can take is' 16 metres (52 ft. 6 in.), but the tank can take a piece 18 metres (59 ft.) long. The tank is filled with water or oil, according to requirements ; by means of a pump and special piping, oil or water can be delivered, during the period of tempering. inside hollovv pieces under treatment. Figs. 153, 154 illustrate the arrangement of this tempering pit. The armour-plate hardening tank, the oil reservoir, and the gun-tempering tank, are in communication with each other by means of pipes ; this arrangement enables the oil to be circulated from one tank to another, according to the nature of work in progress. »ri Tempering Pit for Shafts, Gun Tubes, etc. is closed by a kind of casing consisting of a series of iron frames lined with firebricks and connectée! together, the whole being suspended on a traverse beam that turns on a pivot. During the heating operation, the piece being treated is caused to revolve slowly (one révolution per minute) in order to obtain an equal distribution of heat on ail points. The apparatus to which the piece is sus- pended, rests on a roller path, carried by a beam which is supported from the top of the furnace. The rotary motion is given by an electric motor. The tempering tank is placed opposite the furnace opening, 9.450 metres (31 ft.) distant from it ; il is 2.800 metres (9 ft. 2 in.) in diameter, and 20.500 metres (67 ft. 3 in.) deep ; its capacity is 125 eubic metres (4,415 cubic feet). The greatest length the present A second vertical furnace, but of reduced dimensions, is used for heating small and medium-sized pieces ; its capacity is sufficient to take forgings 10 metres (32 ft. 9 in.) long. The piece is caused to revolve in this furnace during the heat; but instead of being suspended, it rests on the hearth which is set out on a centre. The furnace is on one side of the pit, in the same line as the tempering tank; it is opened in the same way as the larger one, and, as in the case of the other furnace, only a single movement is required to place the piece in the tank. To avoid loss of heat, it is absolutely necessary that the piece should be transferred quickly from the furnace to the tanks. Electric Travellers.—All the appliances described above are served by hvo electric travellers, of 40 and