The Works Of Messrs. Schneider And Co.

118 MESSES. SCHNEIDER AND CO.’S WORKS. currents, two safety fuses, two terminals, and two lamps. The supply to all tlie transforming stations of one depart- ment is regulated by this same switchboard, so that each meter gives the sum of electric enei’gy used in every section. When only one department is served, the meter is placed preferøbly on the secondary circuit of the transformers. At the central station a total meter registers the energy in kilowatt-hours supplied by the alternators. Besides the switchboard of the main primary circuit, tlie transforming stations are fitted with a secondary switchboard formed of a panel and two make-and-breaks, one for primary, the other for the secondary, circuit. The transformers, which are of tlie Ganz type, reduce the current from 2,000 to 110 volts, at which the incandescent lamps are worked. Speaking generally, the distribution of incandescent lighting is by loop circuits, with safety fuses for each lanip, or series of lamps, as the case may be. For lighting with are fitted with reflecting shades and a transparent protecting glass. Two vertical rods, fixed to the standards, serve to guide the lamp when it is lowered for inserting fresh carbons. The box above mentioned contains the self- induction coil for regulating the arc, and a switch for cutting off the current. At the present time, the central station supplies current to 4,000 incandescent and 400 arc lamps Figs. 335 to 338, Plate LXXVI, are respectively a general interiør view, sections, and a plan of the central lighting station. Electric Tramways.—Creusot lias recently supplied the material for an electric tramway (see Figs. 339 and 340) in the district of the Alps. This material is on the Thury system, for which Messrs. Schneider and Co. are the sole concessionaires for France and her colonies. The generating station is built outside the town, and consists o£ two groups of Thury 220 horse-power generators, self-exciting, with a Fig. 339. Electric Tramway. arc lamps the system of three-wire distribution has been adopted, making use of an intermediate terminal, which allows the branching of a neutral wire and the formation of two 50-volt bridges. The lamps are of the Brianne type, of 12 amperes, working at 33 volts at the terminals, with variable focus. As they are branchée! on 50-volt bridges, the excess of voltage is economically absorbed by a self- induction coil, inserted on the lamp circuit. When regu- lated, these lamps work satisfactorily. In the shops they are provided with a reflector and shade, but are not fitted with a protecting glass. They are placed, as a rule, 4 or 5 metres above the floor level ; but they can be raised or lowered by means of a pulley over which the suspension cable of each lamp passes. For lighting the yards and dépôts, the lamps are carried on standards 10 metres high, by a cable which winds round a small winch placed at the base of the standard, and enclosed in a box. These lamps are set at a height of 9 metres, and speed of 325 revolutions, and giving at füll charge an output of 250 amperes at 600 volts. The frame, of hexagonal shape, contains the field magnets. It is divided into six cores, carrying inductor coils and an equal number of polar extensions on the magnets. The frame rests on a cast-iron foundation plate, with the interposition of double wedges, which isolate it magnetically and electrically. The armature consists of a smooth laminated i’ing, fixed on a cast iron centre ; it is drum-wound, and carefully insulated from the shaft. It carries tlie commu- tator, which is mounted on a cast-iron socket, with arms cast in one piece with it. For counteracting the effeets of centrifugal force, the armature conductors placed round the circurnference of the ring are held by steel wire, and the connecting strips are inclosed in cast-iron covering rings of suitable shape. The self-lubricating bearing Blocks are fixed on the foundation plate, their base being turned on the same centre on which the inductors were bored, so as to