Page:Popular Science Monthly Volume 73.djvu/314

310 On the Canadian side of the Niagara River are three great power plants which are now generating about 160,000 horse-power, but which will ultimately develop nearly 400,000 horse-power. The Canadian generators are of much greater capacity than those on the American side and develop from' 10,000 to 12,500 horse-power each. Two of these plants are built over wheelpits like those described on the American side and one of the companies in order to release the water used in its turbines has constructed under the Niagara River a tail race tunnel, the portal of which discharges directly beneath the Horse Shoe Falls.

The Ontario Power Company by erecting a power-house at the level of the lower river and near the foot of the Horse Shoe Falls and by

conveying water through an eighteen-foot conduit from an intake canal above the falls has obviated the necessity and the great expense of building a wheelpit for the utilization of the water pressure and has acquired for its turbines practically the full head of water between the upper and lower rivers, a difference in level of approximately 175 feet.

Directly above the Ontario Company's power-house the great eighteen-foot conduit is tapped by penstocks nine feet in diameter which convey the rushing water to the blades of the turbines. The generator attached to each turbine is thereby caused to revolve at the rate of 187 revolutions a minute. Each generator weighs 231 tons and develops an alternating current of 10,000 to 12,000 horse-power at 12,000 volts, much of which is transformed to a voltage of 60,000 and transmitted with comparatively small loss over aluminum cables to Rochester, Auburn and Syracuse, a maximum distance of 160 miles.