GAS-LIGHTING IN RAILWAY TRAINS. Many methods hhve been tried within the last few years for lighing railway carriages with ordinary street gas; but with only partial success.
The more prevalent schemes are those in which the gas is contained in an elastic receptacle. Mr. Allen's plan, tried on some of the Scotch railways, is to place an india rubber bag or box iu the guard's compartment; it is protected by iron rods or hands, and weighted to press out the contents as the exhaustion goes on. The hag is filled with gas at the station from whence the train starts. A tube from the bag passes out by an opening from the van, and leads up to metal pipes that run along the roofs of the car riages. An india-rubber tube forms an elastic link from carriage to carriage; and small pipes bend down through the roof to supply burners in the interior of each carriage. The guard eau regulate the supply, making the lights brighter or dimmer by easy apparatus under his control. The chief disadvantage of such plans as this is, that nŽ carriages can 'be added to or deducted from the train without disturbing the arrange ments, seeing that the tubing forms:a:connected system from end to end.
Mr. Dalziel's plan, tried OR the South-eastern and the Great Northern lines, enables each carriage to maintain its light irrespective of the others in the train. There is a reservoir underneath the floor of the carriage, consisting of a boiler-like wrought-iron vessel, 9 or 10 ft. long by a foot and a half in diameter; it is invisible, and in no way incommodes the passengers. It is filled at the station, before the train starts, with gas
enough to last all the burners in the carriage daring a double through journey to some distant station aid back again. Pipes lead up the ends of the carriage, and along the top to the spots where they bend down to supply the burners. The gradual exhaus tion of the reservoir would produce a constantly decreasing pressure on the gas, and a consequent dimness of the light; but this is prevented by the use of an automatic com pensating valve, which maintains the pressure equably. The gas, in the first instance, is forced into the reservoir at a pressure of 120 lbs. on the sq. inch.
The Metropolitan or underground railway, running for so great a part of its length through a dark tunnel, would be insupportably gloomy if the carriages were not well lighted. A system of gas-lighting is therefore adopted. Before the of each train, gas is conveyed from a gas-holder up through elastic tubes to the top of each car riage, where an oblong box extending from end to end receives enough of gas to last for two journeys. But of late, methods for condensing and storing up gas have been carried to such perfection as to allow of lighting floating buoys with condensed supplies of gas, enough being introduced at a time to keep up a flame for a period of several weeks.