810 The Outline of Science 



to witness the conversion on a large scale of the energy of fall- 

 ing water into electrical power; there, within a space of a few 

 square miles, are to be found more generating stations operated 

 by water than in any other equal area of the earth's surface. 

 The conditions are ideal. The Niagara River, connecting Lake 

 Erie with Lake Ontario, falls through a vertical distance of over 

 330 feet during a few miles of its course, including the sheer 

 drop of 159 feet of the Falls proper. Every second, more than 

 220,000 cubic feet of water plunge over the rocky ledge into the 

 whirlpool beneath. A simple mathematical calculation will show 

 that the potential energy of this fall and flow combined represents 

 about 8,000,000 horse-power. 



During the last twenty years several generating stations 

 have risen successfully beside the Niagara River, some of them 

 above and others below the Falls ; sufficient water is now deflected 

 from the last without injury to their beauty to supply the 

 neighbourhood and towns within a radius of 100 miles with a 

 bountiful and cheap supply of electric current. Already the Falls 

 of Niagara alone furnish half a million horse-power for lighting 

 and traction to Canadian and American cities; when the full pro- 

 gramme is completed the amount will be doubled. 



The visitor unversed in engineering science might expect to 

 find at Niagara enlarged editions of the water-wheels which are 

 picturesque features of many of our streams. As a matter of 

 fact, there is not such a wheel to be seen, the water motors used 

 turbines are hidden away under the roofs of the power- 

 houses. Each of the eight plants has its distinctive charac- 

 teristics, but they all depend on certain principles: drawing 

 power from an upper level, leading it down to a lower level 

 through great steel tubes called penstocks, passing it through 

 turbines, and finally discharging it into the river below the Falls 

 at a velocity much less than it would acquire in a straight drop 

 through the same distance. 



In order to get a sufficient fall, the Niagara Falls schemes 



