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. The solid axle is of a diameter through the journals of 2 ft. 2 in., a diameter across the flanges of 5 ft. 3 in., length over all 41 ft., and weight 28 tons.
ELECTRICAL NOTES.
Portraits of Morse and Fulton are printed on the reverse of the new two dollar silver certificate, affording a relief to the dreary monotony of ex-presidents, generals and statesmen.
A monster electric elevator is to be erected at Allegheny, Pa. It will be large enough to carry up several wagons at once. The new elevator will save a trip of a mile and a quarter.
An excursion trolley car on the Milwaukee Street Railway has 700 incandescent lights. The car is 32 feet over all. The platforms are 5 foot. The floor of the car is carpeted and a few tables for refreshments are provided.
Amsterdam will have next year an international exhibition of hotel arrangements and accommodations for travelers. Among the features of the exhibition will be an "electric restaurant," without waiters, in which visitors will be served automatically with a complete dinner on pressing an electric button.
Prof. Fleming has shown by experiments that with a 2,000 volt alternating current with a water resistance, that the latter is quite non-inductive, and that the readings of the amperes may be taken, says the Electrical World, as a measurement of the voltage, and the product of the volts and amperes will represent correctly the power consumed.
Our contemporary, The Engineer, suggests doing away with windsails on board steamers entirely and substituting electric fans. In warships the fan ought to be placed where room can be found for it low down in the ship, far below the water line. An electrically driven horizontal fan, with its motor, can be got into the thickness of a deck with its beams, if needs be. This would clearly be better than depending on a flimsy construction, which would certainly be greatly damaged, if not entirely shot away, in action. If clear decks are wanted, the windsail is about as inconvenient as it is ugly, and that is saying a great deal.