Some of the facts and descriptions in the article are a little suspect e.g. "each cubic foot of water ... produces thirty horse-power a second" should read "each cubic foot of water ... produces thirty horsepower-seconds of energy". This is because power is the rate of energy transfer (1 HP = 745.7 W, and 1 W = 1 Joule of energy transferred per second).
To put financial things into perspective, my grandfather (a skilled tradesman) was earning about £3 per week (>45 hrs/wk) at the time this article was written, or 720 English pennies per week. That wage would buy about 720 kWh of electricity in Toronto, according to the article. Today, the average Canadian skilled worker's wage (~40 hrs/wk) in Toronto could buy at least 10 times that much electricity.
The article mentions that in Canada there were hydro dams generating 3,227,000 hp. This equals 2,406 MWe of installed hydro generation. In 1997, the total capacity of Canadian hydro dams was 66,823 MWe - 8,001 MWe in Ontario alone.
As we stand by the side of a silvery lake that seemed so still and silent, or on the bank of a sparkling, trickling stream that "bickers down a valley to join the brimming river," we scarcely realise that in this flowing water in the brooks and rivers of the world lies all the power that the world needs. The glassy pool is so still and the brook that it feeds is so feeble that power would seem to be the last thought that we would associate with them. And yet, as Lord Tennyson knew so well, the stream is working all the time, striving for something that will come to it later.
"With many a curve my banks I fret," says the stream, and slowly but surely it makes its way to the brimming river, slowly but surely the river carves out for itself a bed in the earth, wearing away the softer rocks, until at last, with a triumphant roar, it will dash itself over a cliff with a force that nothing can resist. It has found power.
If we want to say how insignificant a thing is and how little work it can accomplish we usually say it is like "a drop in the ocean." And yet the power in a drop of water is so vast that, added to the power in every other drop, it could do all the work of the world a thousand times over. This is no new discovery, for it has been known from very early times. Solomon had discovered the power of a drop of water when he wrote "A continual dropping weareth away stone." But it is only now, in these days in which we live, that men are making practical use of the tremendous fact that water has stored up in it energy enough to light our cities, drive our machinery, and move our trains.
All over the world men are now harnessing the mighty force of falling water which for thousands of years has been running to waste; and although in England waterpower is not likely to be used to any large extent because of the general flatness of the country, yet in Scotland already factories are being run and work done by the power of harnessed rivers.
The most notable example in the world of the use to which falling water can be put is that of Niagara. Here for centuries a mighty volume of nine hundred million cubic feet of water has been falling over a precipice and running to waste every hour of every day and night. Lord Kelvin once in looking at it spoke of the continuous calamity of Niagara, so stirred was he by the waste of energy.
An engineer of the United States recently made an estimate of the amount of power and money running to waste in that magnificent spectacle of the Falls. If all the momentum of the falling water could be utilised, another 5,000,000 horse-power would be added to the engineering resources of the United States or Canada. Putting the annual value of one horse-power at £10 a year, the whole amount would be worth £50,000,000 a year, or roughly £6000 an hour. In an hour therefore Niagara is wasting the equivalent of a quarter of a million loaves of bread, or to put it in another way 600,000 fresh eggs are being poured down the gorge every hour to make an imaginary omelet.
The mere weight of this water that falls in twenty-four hours is twenty-four million tons, but when we remember that it falls with a tremendous crash into a chasm 160 feet deep we begin to understand how vast, almost beyond human comprehension, are its force and the work it could accomplish.
If we put our finger under the water-tap and then turn on the tap, we find that the water presses with such force against the finger that it cannot be held in, but spurts out all round. What, then, must be the accumulated force of a mighty mass of water falling rapidly from a great height?
Power Worth Tens of Millions of Pounds Running to Waste Each Year
Long ago engineers realised that if only a fraction of the water of Niagara Falls could be harnessed they could be made to do a vast amount of work. It has been estimated by some experts that the power running to waste at the Falls is equal in the amount of its horse-power to more than of all the coal mined in France and Belgium, if that were used in furnaces and turned into steam. This power is worth more a year than pays the interest on the debt to America, and yet, until a few years ago, its possibilities were neglected, and all that it had done had been to wear away a deep bed for the river in the solid rock.
Niagara Falls were only discovered by white men in 1678, and it has been said that up to that time the roaring waters had been feared. Then they were admired, and now they are being used. As far back as I725, a mill-wheel was set up on the edge of the Falls to work a sawmill, but it was not until 1881 that a water-power station was built for the making of electricity.
The Great Steel Tunnels Through Which the Niagara Waters Run
This was a.great success, and showed the world, to its astonishment, what could be done with falling water. From that time to this rapid progress has been made. The greatest care is taken that the natural beauty of the Falls shall not be spoiled. It is not the Falls themselves that are used but the water of the river above, about a mile before it reaches them. It is made to rush through huge steel tunnels, and it then dashes down vertical pipes, one of which has a drop of 135 feet and another 175 feet. This gives the water an enormous momentum, which is used to turn turbines, elaborate water-wheels made of steel. These wheels, in turn, actuate electrical generators, and the electricity is then conveyed by wires to the cities all round the Falls.
After revolving the turbines the water runs away through other tunnels called tail-races, which carry it below the Falls, so that the water that has been imprisoned in the pipes meets the water which has fallen over the cliff. One of these tunnels is more than a mile and a quarter long, and took a thousand men three years to make. Three hundred thousand tons of rock had to be excavated, and the tunnel was then lined with sixteen million bricks. Visitors are able to go into this tunnel, and from a gallery watch the water rush away. It is nearly 160 feet below the bed of the river.
The exit of the tunnel is in the face of the rocky cliff over which the waters of Niagara crash. There is thus a smaller torrent of rushing water, though tremendous in its way, bursting from the tunnel in the rock behind the Falls.
The Dangerous Rapids and Whirlpools Miles Below the Falls
The waters of the Falls leap over the precipice with such fury that they do not stream directly down the face of the cliff at all, but strike the river sixty feet or more from the rocky wall, the space between the Falls and the rock being filled with a mass of whirling spray. We might naturally suppose that the river round about where the Falls strike it would be a seething cauldron of furious waves and whirlpools. But, on the contrary, the river is quite calm for two miles below the Falls, and boats can go backward and forward upon its waters in perfect safety. The explanation of this strange fact is that the Falls crash into the river with such force that the descending waters go right under the surface of the river, flow along the bottom, and only come up again to the light two miles from the Falls.
Here there are dangerous rapids, and a great whirlpool that sweeps round and round and will suck down anything that comes within its deadly grasp. The cause of this whirlpool is a sharp turn in the river, which results in the rushing water being hurled against the Canadian side and then being flung back with a circular motion.
The latest scheme for harnessing the waters of Niagara was a much more elaborate business than the older methods. It involved the construction of an artificial waterway thirteen miles long, and the fall of water through the final conduits to the turbines is 305 feet! How can that be, considering that the Horse Shoe Falls are only 155 feet high?
How the Water Was Made to Drop Twice the Depth of the Falls
The answer is that Lake Ontario, into which the Niagara River flows, is 327 feet lower than Lake Erie, of which the Niagara River is the outlet, and the engineers set themselves to harness as much of this big drop as they could. They made the thirteen mile waterway from the calm water above to the calm water below, leaving on one side not only the Falls but the Rapids above them, and the Whirlpool and the other turbulent reaches below. This artificial waterway falls only twelve feet in its whole length, while the river above and below it falls another ten feet. This leaves 305 feet for the fall in the conduits at the lower end of the canal.
For a third of its distance the canal is made by deepening and widening the Niagara tributary, the Welland River, from its mouth at Chippawa to the village of Montrose. The rest is cut through the rock and earth to the point above Queenston, on the Lower River, where the canal broadens out in a triangle and empties itself into the great tubes which take it over the face of a cliff to the turbines below. The result of this elaborate arrangement is that each cubic foot of water falling on the turbines at Queenston produces thirty horse-power a second against only half as much as that which is produced by the smaller drop at the older stations.
The Ten Great Turbines with Six Hundred Thousand Horse-Power
To make this canal seventeen million cubic yards of rock had to be removed and nearly half a million cubic yards of concrete laid down. Eighty miles of railway were laid for dealing with this vast amount of material, and the largest electrically driven shovels in the world were used, each capable of loading a car of twenty cubic yards, standing sixty feet above, in a minute and a half! Many bridges had to be built to carry important railway lines as well as the highways over the canal.
The power-house is picturesquely situated at the mouth of the gorge worn by the river where it emerges on the wide plain and becomes navigable once more six miles above Lake Ontario. Each of the ten turbines has a capacity of 60,000 horse-power (600,000 horse-power in all), and each of the ten electric generators is mounted directly above its own turbine, all revolving on a common shaft. These huge machines weigh over six hundred tons each. They are air-cooled, and their own weight of air must pass over them in two and a half hours for the purpose of keeping them cool.
It is said that the average home in the Ontario towns gets electric lighting for less than a shilling a week, while for very little more it can set itself up with electric fans, irons, washing machines, vacuum cleaners, toasters, light, and cooking. Toronto, ninety miles from Niagara, pays under a penny per kilowatt per hour, and Windsor, 250 miles from its generating station, pays about a farthing more.
The supply of electricity in country districts is usually too expensive for an ordinary trading company, but the thing is managed in Ontario. The Government pays half the cost of all distributing lines outside the towns. Imagine what this must mean to the lonely farmer and his wife. For less than thirty shillings a month they can have electricity to light their home and farm buildings, and to drive pumps, cream separators, churns, and milking machines.
The Colossal Water Power Developed in Canada and the States
The control of water-power in Ontario is in the hands of the Government Electric Power Commission, which has bought up two existing power plants at Niagara, and which, on the completion of the Queenston-Chippawa project, will control nearly a million horse-power of energy. The commission also has control of several other waterpower systems which supply cheap electric power over a wide area. The value of the Niagara system is now nearly thirty million pounds, and of the whole gigantic undertaking throughout the Province over fifty million pounds.
Then there are vast hydro-electric power undertakings on the American side of Niagara Falls supplying cheap power to run railways and trams and factory machinery of all kinds.
It is said that in Canada alone there is already developed 3,227,000 horse-power of hydroelectric energy; while in the United States it is said to reach the astonishing figure of ten millions!
เข้าสู่ระบบติดต่อกัน Aerial Views (137 kB)
Power House (131 kB)
Forebay Screen House and Power Canal (143 kB)
เข้าสู่ระบบติดต่อกัน Hydro Station Schematic (116 kB)
The Niagara Gorge (120 kB)