Project Gutenberg #4710
The Story of Electricity
John Munro
1902Munro's popular history of electrical science and its early applications, prepared chapter by chapter from Project Gutenberg HTML.
Project Gutenberg #4710 Public domain in the United States Cover source Local typographic cover created for MojiMori from public-domain source metadata
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The water-power of the cataract has been employed from olden times. The French fur-traders placed a mill beside the upper rapids, and the early British settlers built another to saw the timher used in their stockades. By-and-by, the Stedman and Porter mills were established below the Falls; and subsequently, others which derived their water-supply from the lower rapids by means of raceways or leads. Eventually, an open hydraulic canal, three- fourths of a mile long, was cut across the elbow of land on the American side, through the town of Niagara Falls, between the rapids above and the verge of the chasm below the Falls, where, since 1874, a cluster of factories has arisen, which discharge their spent water over the cliff in a series of cascades almost rivalling Niagara itself. This canal, which only taps a mere drop from the ocean of power that is running to waste, has been utilised to the full; and the decrease of water-privileges in the New England States, owing to the clearing of the forests and settlement of the country, together with the growth of the electrical industries, have led to a further demand on the resources of Niagara.
With the example of Minneapolis, which draws the power for its many mills from the Falls of St. Anthony, in the Mississippi River, before them, a group of far-seeing and enterprising citizens of Niagara Falls resolved to satisfy this requirement by the foundation of an industrial city in the neighbourhood of the Falls. They perceived that a better site could nowhere be found on the American Continent. Apart from its healthy air and attractive scenery, Niagara is a kind of half-way house between the East and West, the consuming and the producing States. By the Erie Canal at Tonawanda it commands the great waterway of the Lakes and the St. Lawrence. A system of trunk railways from different parts of the States and Canada are focussed there, and cross the river by the Cantilever and Suspension bridges below the Falls. The New York Central and Hudson River, the Lehigh Valley, the Buffalo, Rochester, and Pittsburgh, the Michigan Central, and the Grand Trunk of Canada, are some of these lines. Draining as it does the great lakes of the interior, which have a total area of 92,000 square miles, with an aggregate basin of 290,000 square miles, the volume of water in the Niagara River passing over the cataract every second is something like 300,000 cubic feet; and this, with a fall of 276 feet from the head of the upper rapids to the whirlpool rapids below, is equivalent to about nine million, or, allowing for waste in the turbines, say, seven million horse- power. Moreover, the great lakes discharging—into each other form a chain of immense reservoirs, and the level of the river being little affected by flood or drought, the supply of pure water is practically constant all the year round. Mr. R. C. Reid has shown that a rainfall of three inches in twenty-four hours over the basin of Lake Superior would take ninety days to run off into Lake Huron, which, with Lake Michigan, would take as long to overflow into Lake Erie; and, therefore, six months would elapse before the full effect of the flood was expended at the Falls.
The first outcome of the movement was the Niagara River Hydraulic Power and Sewer Company, incorporated in 1886, and succeeded by the Niagara Falls Power Company. The old plan of utilising the water by means of an open canal was unsuited to the circumstances, and the company adopted that of the late Mr. Thomas Evershed, divisional engineer of the New York State Canals. Like the other, it consists in tapping the river above the Falls, and using the pressure of the water to drive the number of turbines, then restoring the water to the river below the Falls; but instead of a surface canal, the tail-race is a hydraulic tunnel or underground conduit. To this end some fifteen hundred acres of spare land, having a frontage just above the upper rapids, was quietly secured at the low price of three hundred dollars an acre; and we believe its rise in value owing to the progress of the works is such that a yearly rental of two hundred dollars an acre can even now be got for it. This land has been laid out as an industrial city, with a residential quarter for the operatives, wharves along the river, and sidings or short lines to connect with the trunk railways. In carrying out their purpose the company has budded and branched into other companies—one for the purchase of the land; another for making the railways; and a third, the Cataract Construction Company, which is charged with the carrying out of the engineering works, for the utilisation of the water-power, and is therefore the most important of all. A subsidiary company has also been formed to transmit by electricity a portion of the available power to the city of Buffalo, at the head of the Niagara River, on Lake Erie, some twenty miles distant. All these affiliated bodies are, however, under the directorate of the Cataract Construction Company; and amongst those who have taken the most active part in the work we may mention the president, Mr. E. D. Adams; Professor Coleman Sellers, the consulting engineer; and Professor George Forbes, F. R. S., the consulting electrical engineer, a son of the late Principal Forbes of Edinburgh.
In securing the necessary right of way for the hydraulic tunnel or in the acquisitom of land, the Company has shown consummate tact. A few proprietors declined to accept its terms, and the Company selected a parallel route. Having obtained the right of way for the latter, it informed the refractory owners on the first line of their success, and intimated that the Company could now dispense with that. On this the sticklers professed their willingness to accept the original terms, and the bargain was concluded, thus leaving the Company in possession of the rights of way for two tunnels, both of which they propose to utilise.
The liberal policy of the directors is deserving of the highest commendation. They have risen above mere "chauvinism," and instead of narrowly confining the work to American engineers, they have availed themselves of the best scientific counsel which the entire world could afford. The great question as to the best means of distributing and applying the power at their command had to be settled; and in 1890, after Mr. Adams and Dr. Sellers had made a visit of inspection to Europe, an International Commission was appointed to consider the various methods submitted to them, and award prizes to the successful competitors. Lord Kelvin (then Sir William Thomson) was the president, and Professor W. C. Unwin, the well-known expert in hydraulic engineering, the secretary, while other members were Professor Mascart of the Institute, a leading French electrician; Colonel Turretini of Geneva, and Dr. Sellers. A large number of schemes were sent in, and many distinguished engineers gave evidence before the Commission. The relative merits of compressed air and electricity as a means of distributing the power were discussed, and on the whole the balance of opinion was in favour of electricity. Prizes of two hundred and two hundred and fifty pounds were awarded to a number of firms who had submitted plans, but none of these were taken up by the Company. The impulse turbines of Messrs. Faesch & Piccard, of Geneva, who gained a prize of two hundred and fifty pounds, have, however, been adopted since. It is another proof of the determination of the Company to procure the best information on the subject, regardless of cost, that Professor Forbes had carte blanche to go to any part of the world and make a report on any system of electrical distribution which he might think fit.
With the selection of electricity another question arose as to the expediency of employing continuous or alternating currents. At that time continuous currents were chiefly in vogue, and it speaks well for the sagacity and prescience of Professor Forbes that he boldly advocated the adoption of alternating currents, more especially for the transmission of power to Buffalo. His proposals encountered strong opposition, even in the highest quarters; but since then, partly owing to the striking success of the Lauffen to Frankfort experiment in transmitting power by alternating currents over a bare wire on poles a distance of more than a hundred miles, the directors and engineers have come round to his view of the matter, and alternating currents have been employed, at all events for the Buffalo line, and also for the chief supply of the industrial city. Continuous currents, flowing always in the same direction, like the current of a battery, can, it is true, be stored in accumulators, but they cannot be converted to higher or lower pressure in a transformer. Alternating currents, on the other hand, which see-saw in direction many times a second, cannot be stored in accumulators, but they can be sent at high pressure along a very fine wire, and then converted to higher or lower pressures where they are wanted, and even to continuous currents. Each kind, therefore, has its peculiar advantages, and both will be employed to some extent.
With regard to the engineering works, the hydraulic tunnel starts from the bank of the river where it is navigable, at a point a mile and a half above the Falls, and after keeping by the shore, it cuts across the bend beneath the city of Niagara Falls, and terminates below the Suspension Bridge under the Falls at the level of the water. It is 6700 yards long, and of a horseshoe section, 19 feet wide by 21 feet high. It has been cut 160 feet below the surface through the limestone and shale, but is arched with brick, having rubble above, and at the outfall is lined on the invert or under side with iron. The gradient is 36 feet in the mile, and the total fall is 205 feet, of which 140 feet are available for use. The capacity of the tunnel is 100,000 horse- power. In the lands of the company it is 400 feet from the margin of the river, to which it is connected by a canal, which is over 1500 feet long, 500 feet wide at the mouth, and 12 feet deep.
Out of this canal, head-races fitted with sluices conduct the water to a number of wheel-pits 160 feet deep, which have been dug near the edge of the canal, and communicate below with the tunnel. At the bottom of each wheel-pit a 5000 horse-power Girard double turbine is mounted on a vertical shaft, which drives a propeller shaft rising to the surface of the ground; a dynamo of 5000 horse- power is fixed on the top of this shaft, and so driven by it. The upward pressure of the water is ingeniously contrived to relieve the foundation of the weight of the turbine shaft and dynamo. Twenty of these turbines, which are made by the I. P. Morris Company of Philadelphia, from the designs of Messrs. Faesch and Piccard, will be required to utilize the full capacity of the tunnel.
The company possesses a strip of land extending two miles along the shore; and in excavating the tunnel a coffer-dam was made with the extracted rock, to keep the river from flooding the works. This dam now forms part of a system by which a tract of land has been reclaimed from the river. Part of it has already been acquired by the Niagara Paper Pulp Company, which is building gigantic factories, and will employ the tailrace or tunnel of the Cataract Construction Company. Wharfs for the use of ships and canal boats will also be constructed on this frontage. By land and water the raw materials of the West will be conveyed to the industrial town which is now coming into existence; grain from the prairies of Illinois and Dakota; timber from the forests of Michigan and Wisconsin;