The screw propeller of the Edison and Sim's torpedo is also driven by an electric motor. In this case the current is conveyed from the ship or fort which discharges the torpedo by an insulated conductor running off a reel carried by the torpedo, the "earth" or return half of the circuit being the sea-water. All sorts of machinery are now worked by the electric motor--for instance, cranes, elevators, capstans, rivetters, lathes, pumps, chaff-cutters, and saws. Of domestic appliances, figure 80 shows an air propeller or ventilation fan, where F is a screw-like fan attached to the spindle of the motor M, and revolving with its armature. Figure 81 represents a Trouve motor working a sewing- machine, where N is the motor which gears with P the driving axle of the machine. Figure 82 represents a fine drill actuated by a Griscom motor. The motor M is suspended from a bracket A B C by the tackle D E, and transmits the rotation of its armature by a flexible shaft S T to the terminal drill O, which can be applied at any point, and is useful in boring teeth. Now that electricity is manufactured and distributed in towns and villages for the electric light, it is more and more employed for driving the lighter machinery. Steam, however, is more economical on a large scale, and still continues to be used in great factories for the heavier machinery. Nevertheless a day is coming when coal, instead of being carried by rail to distant works and cities, will be burned at the pit mouth, and its heat transformed by means of engines and dynamos into electricity for distribution to the surrounding country. I have shown elsewhere that peat can be utilised in a similar manner, and how the great Bog of Allen is virtually a neglected gold field in the heart of Ireland. [Footnote: The Nineteenth Century for December 1894.] The sunshine of deserts, and perhaps the electricity of the atmosphere, but at all events the power of winds, waves, and waterfalls are also destined to whirl the dynamo, and yield us light, heat, or motion. Much has already been done in this direction. In 1891 the power of turbines driven by the Falls of Neckar at Lauffen was transformed into electricity, and transmitted by a small wire to the Electrical Exhibition of Frankfort-on-the-Main, 117 miles away. The city of Rome is now lighted from the Falls of Tivoli, 16 miles distant. The finest cataract in Great Britain, the Falls of Foyers, in the Highlands, which persons of taste and culture wished to preserve for the nation, is being sacrificed to the spirit of trade, and deprived of its waters for the purpose of generating electricity to reduce aluminium from its ores. The great scheme recently completed for utilizing the power of Niagara Falls by means of electricity is a triumph of human enterprise which outrivals some of the bold creations of Jules Verne.