The currents furnished by the power-houses at Niagara are all alternating. This kind of current being decided upon for various reasons. It can be used for driving dynamos as well as any, and as nearly all the power developed at the Falls is used in this way no provision is made for a direct current. Where a direct current is desired the electricity is made to drive a dynamo of the alternating type which in turn is made to drive another of the kind of current desired. Establishments on or near the grounds use the power furnished them direct from the power-house. When the power must be transmitted to a distance, it becomes necessary to use a step-up transformer for the purpose of losing as little power as necessary in the transmission, this to produce a higher voltage. When the current reaches those places where it is to be used a low voltage is again obtained by the step-down transformer. Almost, if not quite as interesting as the development of all this power, together with its transmission, are the manufacturing establishments springing up here to take advantage of the great opportunities offered by the harnessing of this mighty cataract. Among those which stretch along the river for several miles are to be found those interested in the manufacture of carborundum, aluminum, carbide, graphite, caustic potash, muriatic acid, emery wheels, railway supplies, hook-and-eye fastenings, and shredded wheat, which are of special interest to the visitor. Industrialism has seized upon the immense power of Niagara and is now shaping it into commodities for the use of man. Now what is the real menace to the Falls? Many lament the erection of the power plants and manufacturing establishments in the vicinity; but those, at least already in existence, have come to stay. So we may turn our attention from the marring of the surrounding beauty to the Falls themselves.