Austria is turning out a new variety of Mannlicher repeating rifle for its army, which is the lightest rifle in the world, weighing 3.3 kilogrammes, seven pounds and four ounces, instead of 4.4 kilogrammes, nine pounds eleven ounces, the weight of the old pattern. All the individual parts in the new rifle, including the locking box, the magazine and the barrel, are lighter than in the old. The bayonet and sheath are also made lighter.

A trolley express car system is now in successful operation in Brooklyn, N.Y. The trolley system of Brooklyn is one of the most extensive in the world, and many of the outlying districts are now served with great dispatch. Parcels are collected by wagons, they are then brought to the cars, and, after being carried to the nearest express station to their destination, they are then transported again by wagons. On Sundays the cars are run to carry bicycles.

In Stanislau oil gas is being a good deal used for incandescent lighting, says the Gas World. The gas is used at a pressure of from 1.1 in. to 1.2 in. When 1.7 cubic feet per hour is used the Welsbach mantle gives 69½ candles at first, 65 candles after 120 hours, 48¼ candles after 500 hours. The fall in lighting power is comparatively slow with oil gas, and the mantles are not so much worn by lighting the gas, for the kind of oil gas is not as explosive as that of coal gas. The mantles are found to last from 400 to 600 hours.

During the construction of the Simplon tunnel every possible alleviation will be made for the workmen employed, says the Railway Review. On leaving the tunnel when they are hot and wet through they will go at once to the douche and bathrooms provided for their accommodation, where, after a refreshing shower bath, they will resume their dry clothes. The sheds from which the workmen leave the tunnel are to be covered in and closed at the sides so as to protect them from cold. Water will be taken at intervals to the workmen who may require it, either from the pipe which feeds the drills or from that which brings water for cooling. No provision has been made as regards workmen's lodgings, because it is supposed that they will easily find accommodation in the neighborhood. As it is believed that the temperature of the rock of the Simplon tunnel may reach a maximum of 104° F., costly measures will have to be taken to cool the air in many parts where the works are to be carried on.

"Recent Developments in Lighthouse Engineering" was the title of a paper read recently at the Institution of Civil Engineers, by Mr. N.G. Gedye, says the Colliery Guardian. The author pointed out the marked development which has of late years taken place in the direction of reducing the length of flash emitted by lighthouse apparatus to a minimum, and the consequent increase obtained in intensity. The apparatus now being erected at Cape Leeuwin, Western Australia, gives a flash of one-fifth of a second duration every five seconds. It is the most powerful oil light in the world, the flash being over 145,000 candle power emitted from a pair of dioptric lenses mounted on a mercury float revolving once every ten seconds. Each of the two lenses is 8 feet in diameter. The powers of these oil lights are far exceeded by electric lighthouse lights, there being several in France up to 23,000,000 candle power, while there has recently been established at Fire Island, at the entrance to New York Harbor, an electric light, of French design and construction, of 123,000,000 candle power; this is the most powerful lighthouse light in the world.

Discussing the use of potassium cyanide for steel-hardening purposes, T.R. Almond, of Brooklyn, N.Y., suggests that this salt assists the hardening process because of its powerful deoxidizing properties, and also because it forms a liquid film on the surface of the steel, which causes a more perfect contact between the steel and the water, thereby permitting a more rapid abstraction of heat. The inevitable formation of a thin coat of oxide is unfavorable to the process of rapid cooling; and as rapid cooling seems to be the one thing necessary for success in hardness, any means used for the removal of a bad conductor of heat, like the black oxide, will be of advantage, and more especially if this means also results in the formation of a liquid film on the steel surface having the affinity for water which, it is well known, is peculiar to potassium cyanide. Mr. Almond recommends the removal of all scale or oxide from the surfaces of steel to be hardened, either by pickling or by the cyanide. Steel covered with a very thin film of oxide will take the heat less quickly when immersed in hot lead than if the steel be bright before being immersed.

This being the case, it would seem to follow that, because of a film of oxide, heat will leave steel more slowly when being cooled by water.

The gigantic wheel, now being erected on the site of the old bowling green in a corner of the Winter Gardens, Blackpool, was commenced on December 1, 1895, says the Building News. The work of erecting the supports was not finished until the third week in March, and then the most difficult portion of the work, viz., that of hoisting the axle, was commenced. The axle, a steel forging weighing over 28 tons and measuring nearly 41 ft. long and 26 in. in diameter, was forged at the works of Messrs. W. Beardmore & Company, of Glasgow. The axle and bearings being fixed complete, the work of building the rims of the wheel will be pushed forward rapidly under the direction of Mr. Walter B. Basset, who also built the Earl's Court wheel. The carriages, thirty in number, and each capable of carrying forty persons, are rapidly approaching completion in the works of Messrs. Brown, Marshall & Company, of Birmingham. The driving engines and most of the intermediate gearing are already in position in the engine house. These engines will operate two steel wire ropes, one on either side of the rim of the wheel, and arrangements have been made and provided for in such gearing to enable the wheel to be turned at a quicker speed than that at Earl's Court. The Blackpool wheel will be able to carry more passengers per hour than its predecessor in London. The particulars of the great wheel are: Total height above sea level, 250 ft.; total diameter (across centers of pins), 200 ft.; total weight, 1,000 tons.