The nearest approach to its achievement has occurred in the laboratories of Mr. Nikola Tesla, the famous electrician. By means of a special oscillator, invented by himself, he has succeeded in throwing the ether particles into such an intense state of vibration that they become luminous. In other words, he has created vibrations of the enormous rapidity of light, and this without the creation of heat waves to any appreciable extent.
An incandescent lamp, mounted on a powerful coil, is lit without contact by ether waves transmitted from a cable running round the laboratory, or bulbs and tubes containing highly rarefied gases are placed between two large plate-terminals arranged on the end walls. As soon as the bulbs are held in the path of the currents passing through the ether from plate to plate they become incandescent, shining with a light which, though weak, is sufficiently strong to take photographs by with a long exposure. Tesla has also invented what he calls a “sanitary” light, as he claims for it the germ-killing properties of sunshine. The lamps are glass tubes several feet long, bent into spirals or other convolutions, and filled before sealing with a certain gas. The ends of the glass tube are coated with metal and provided with hooks to connect the lamp with an electric current. The gas becomes luminous under the influence of current, but not strictly incandescent, as there is very little heat engendered. This means economy in use. The lamps are said to be cheaply manufactured, but as yet they are not “on the market.” We shall hear more of them in the near future, which will probably witness no more interesting development than that of lighting.
Before closing this chapter a few words may be said about new heating methods. Gas stoves are becoming increasingly popular by reason of the ease with which they can be put in action and made to maintain an even temperature. But the most up-to-date heating apparatus is undoubtedly electrical. Utensils of all sorts are fitted with very thin heating strips (formed by the deposition of precious metals, such as gold, platinum, &c., on exceedingly thin mica sheets), through which are passed powerful currents from the mains. The resistance of the strip converts the electromotive energy of the current into heat, which is either radiated into the air or into water for cookery, &c.
In all parts of the house the electric current may be made to do work besides that of lighting. It warms the passages by means of special radiators—replacing the clumsy coal and “stuffy” gas stove; in the kitchen it boils, stews, and fries, heats the flat-irons and ovens; in the breakfast room boils the kettle, keeps the dishes, teapots, and coffee-pots warm; in the bathroom heats the water; in the smoking-room replaces matches; in the bedroom electrifies footwarmers, and—last wonder of all—even makes possible an artificially warm bed-quilt to heat the chilled limbs of invalids!
The great advantage of electric heating is the freedom from all smell and smoke that accompanies it. But until current can be provided at cheaper rates than prevail at present, its employment will be chiefly restricted to the houses of the wealthy or to large establishments, such as hotels, where it can be used on a sufficient scale to be comparatively economical.
THE END
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THE ROMANCE OF MODERN ENGINEERING