The incandescent light is entirely free from the products of combustion which heat and vitiate the air; it enables us to see pictures and flowers as by daylight; it supports plants instead of poisoning them, and enables many industries to be carried on by night as well as by day. Add to this an almost perfect immunity from danger of fire and no fear of explosion. When it is realized that a gas flame gives out seventeen times as much heat as an incandescent lamp of equal light-giving power, and that an ordinary gas flame vitiates the air as much as the breathing of ten persons, some idea may be formed of the advantage of the electric light from a sanitary point of view. To this may be added absence of injury to books, walls and ceilings. Visitors to the Savoy Theatre in London will doubtless have seen the adaptability of this light for places of public amusement and it is now possible to sit out a play in a cool and pleasant atmosphere without incurring a severe headache. To theatrical managers the light offers in addition unusual facilities for producing spectacular effects, such as the employment of green, red, and white lamps to represent night, morning, and daylight. The freedom from weariness and lassitude after spending an evening in an electrically lighted apartment must be experienced in order to be appreciated. The electric light very readily adapts itself to the interior fittings and decorations of houses and public buildings, and it can be placed in positions where gas could not be used on account of the danger of fire. The old lines of gas-fittings should be avoided as far as possible, and the lights placed singly where required and not “bunched” together. For the lighting of mines, electricity must stand unrivalled, though little has as yet been done in this direction. Its speedy adoption either voluntarily or by Act of Parliament, with the employment of lime cartridges instead of blasting by gunpowder, will in the future render explosions in mines almost an impossibility. In some cases, gas may yet for some time compete with the electric light both in brilliancy and economy; for the electric light has spurred on the gas Companies to the improved lighting of many of our public streets and places. With the general introduction of electricity for the purpose of lighting comes the introduction of electricity for the production of power; for the same current entering by the same conductors can be used for the production of light or of power, or of both. The same plant at the central stations will supply power by day and light by night, with evident economy. Electricity will thus be used for driving sewing-machines, grinding, mixing, brushing, cleaning, and many other domestic purposes. In many trades requiring the application of power for driving light machinery for short periods, electricity will be of the greatest value, and artisans will have an ever ready source of power at their command in their own homes.