It has been found, however, that, adapted as some of the arc regulators are for the illumination of streets and large areas, none of them are at all able to compete with gas in the lighting of private houses. Not only do they require the constant attention of skilled workmen to renew the carbons and to clean the mechanism, but they give far too strong and dazzling a light for any but very large apartments. For domestic lighting we therefore come to quite a new departure in electric lamps; instead of the arc we have the incandescent regulator. If an intense electric current be transmitted through a fine platinum wire, the latter will, in a very few seconds, become white hot, and give a considerable amount of light. If such a platinum wire be enclosed in a glass globe, from which the air has been extracted, we have one kind of incandescent lamp, so called because the light is produced through the incandescence or intense heating of a platinum or other conductor. It was a lamp such as this that, when brought out by Mr. Edison two years ago, produced such a scare among holders of gas shares. It was not, however, a practical invention; it was found that the electric current constantly melted the platinum, or broke the glass envelope, after which the lamp was of course entirely useless. In vain Mr. Edison tried various alloys of platinum and iridium; nothing of that nature was found that could resist the intense heat produced by the electricity. While, however, the incandescent lamp was not progressing very rapidly in America, in England Mr. Swan, of Newcastle, who had been experimenting with the electric light for some time, brought out another kind of regulator, which has given rise to great expectations. The Swan lamp consists of a pear-shaped globe, blown out of glass, and from which all the air, or at least as much as can be, has been exhausted. In this globe there is a tiny carbon filament, manufactured of carbonized thread, in the form of a loop, which is attached to two platinum wires which project through the glass bulb. On an electric current being passed through the carbon, by means of wires attached to the platinum projections, a soft yet brilliant light is obtained. These lamps, which give a light corresponding in power and color to an ordinary gas flame, can now be obtained for five shillings each, and it is probable that this price may yet be still further reduced. Mr. Edison also, having abandoned his earlier platino-iridium regulator, has brought out another lamp very similar to Mr. Swan’s. In his case the carbon filament is formed of carbonized bamboo, and the glass bulb is of an elongated form. Incandescent lamps have also been invented by Maxim, Crooks, Fox Lane, and others; but they only differ in details of manufacture from those of Swan and Edison.