Already some 1.550 acres of land have been acquired. of which 1,000 acres will he re. served for manufacturing purposes, 150 acres for a terminal railway, and about 400 acres for a residential district. This latter part is being laid out on a systematic plan. The great main toil-race tunnel has been commenced, the contract having been given to Messrs. Rodgers & Clement. This tunnel will at the outset be 7,000 ft. in length, and 400 sq. ft. in section. It will be capable of discharging the tail water of turbines developing 100,000 horse-power. At. the present. time, 6,700 ft, of heading, and 6,251 ft. of bench have been driven. Arrangements have also been made for developing initially about 20,000 horse power. Fig. 1 shows the position of the tunnel, the intake canal, and the proposed arrange ment of the manufacturing quarter. Fig. 2 shows the arrangement proposed for the primary power stations. Fig. 3 shows a turbine wheel pit, with the arrangement of head race and discharge tunnel.
Systems of Power Distribution.—Probably to an engineer considering the conditions with any care, it would soon appear that the provision of a tunnel tail race anti hydraulic machinery solved only half the Niagara problem, and that the least difficult and doubtful half. It is likely Mr. Evershed and those acting with him considered that nothing more was wanted for utilizing Niagara than the adoption of plans already in successful opera tion in the United States. but on a more gigantic scale. It does not seem to have been at all recognized at first that the magnitude of the Niagara scheme was itself a condition ren dering the older methods of utilizing water power. if not physically impracticable, at least of doubtful commercial success. Nowhere else in the world has water power been utilized on so great a scale as in the United States. The towns of Lowell, Lawrence, Holyoke. and Manchester owe their very existence as manufacturing centers to water power. At these towns, less favorably situated than Niagara, a fall was artificially created by building a dam across a river ; from the up stream side of the dam, water was supplied to mills by canals, and they discharged it below the dam by other canals. The mill owners constructed the requisite machinery, and the water-power companies obtained a return on their expendi ture by a rental based on the quantity of water supplied. Generally, in these towns the fall utilized is not very great. so that no very expensive excavations are required for the wheels ; also the distribution of the water and ass:essment of the rental presents no special difficulty. The cost for the water supplied varies in different towns : on the average, the rental appears to be from $14 to $18 per annum per effective horse-power delivered from the turbine shaft. The additional charge for interest on capital expended by the mill owner in
hydraulie*machinery. repairs, wages of attendants. etc., would appear to be about $8 per horse-power per annum. So that the total cost of an effective horse-power to the mill owners appears to be from $22 to $28 per annum.
At Niagara no dam has to lie constructed On the other hand, the tail-race tunnel is a work of such a kind that its cost per horse-power utilized diminishes very much as the whole amount of power dealt with is greater. The actual section of the tunnel is 490 sq. ft., and it is intended to discharge 8,800 cub. ft. per second. Taking the effective fall, after deducting all possible losses, at 160 ft., and assuming moderately good turbines, this quantity of water will yield 100,000 effective horse-power. The cost of the tunnel amounts to less than $10 per effective horse-power. A rock tunnel lined with brick is practically as durable as the rock itself, and the interest on this sum is but an insignificant item in the charge for power if the tunnel is fully worked. With 8.800 cub. ft. per second, the velocity in the tail race tunnel will be only 18 ft. per second if it discharges full bore, or perhaps 25 ft. per second if it discharges as an open canal. Neither of these velocities is too great for a masonry lined rock tunnel.
The construction of a tail-race tunnel imposes, therefore, no difficulty in the way of utiliz ing Niagara, provided it is undertaken on a large scale. It is only when the details of a system of surface canals for distributing so enormous a volume of water to different con sumers are considered, and the cost and complexity of a system of secondary tunnels to re-collect the water from different consumers, and discharge it into the main tunnel, that a doubt arises as to the practicability of methods in which each consumer takes the water required for power on his own land, and constructs his own wheel pits and machinery. Part of the water power at Niagara will undoubtedly be utilized in this way, especially on land nearest adjacent to the main tunnel. In the case of an industry requiring a very large amount of power, it will be practicable and economical for manufacturers ti take the water and construct wheel pits, necessarily 180 ft. in depth, and the machinery for utilizing it. But such a method is little adapted for smaller factories. It would probably be a long time before at Niagara a sufficient number of large manufacturers could be attracted to utilize in this way 120,000 horse-power.