The Niagara River, upon which the Falls are situated, 22 M. from its head in Lake Erie, and 14 M. from its mouth in Lake Ontario, forms the outlet of four of the five Great Lakes (Erie, Huron, Michigan and Superior). It descends about 330 ft. in its course of 36 M. About 15 M. from Lake Erie the river narrows and the rapids begin. In the last three quarters of a mile above the falls, the water descends 55 ft. and the velocity is enormous. The basin of the Falls has a depth of from 100 to 192 ft. During cold winters the spray covers the grass and trees in the park along the cliff with a delicate veneer of ice, while below the Falls it is tossed up and frozen into a solid arch. Adjoining the left (Canadian) bank is the greater division, Horseshoe Fall, 155 ft. high and curving to a breadth of 2,600 ft. The American Fall, adjoining the right bank, is 162 ft. high and about 1,400 ft. broad. In recognition of their æsthetic value the province of Ontario and the State of New York have reserved the adjacent land as public parks. In the midst of the Rapids lies a little group of islands, among them the famous Goat Island. Besides the wonderful view it affords, its western end gives a unique example of absolutely virgin forest.
The Indians used to fish and hunt, crossing the Rapids on foot and supporting their steps with tall wooden poles spiked with iron. The necessity, on one occasion, of saving two marooned comrades on the island, taught them this means of crossing, which they had never before attempted.
The Niagara River runs half its length on an upper plain, then drops at the falls into a narrow gorge through which it courses seven miles to the escarpment, the crest of which is a bed of limestone—60 ft. thick at the falls. The water plunges into a deep basin hollowed out of soft shale, which, as well as the escarpment, is being constantly worn away. The site of the cataract retreats upstream and the gorge is lengthened at a rate of about five ft. a year. It is evident that the whole gorge has been dug out by the river, and many attempts have been made to determine the time consumed in the work. The solution of the problem would aid in establishing a relation between the periods and ages of geologic time and the centuries of human chronology. The Horseshoe Fall wore its cliff back 335 ft. in about 63 years. Geologists have computed 25,000 years as a lower limit for plausible estimates of the river, but have been able to set no upper limit.
The Canadian and American shores are connected by three bridges, one of which a suspension carrying all classes of traffic, is 1,240 ft. long. The flow of water in the river averages 222,000 cubic ft. per second, though it sometimes falls as low as 176,000 cubic ft.
On March 29, 1848, Niagara ran dry, and persons walked in the rocky channel bed of the American Rapids between Goat Island and the mainland. This phenomenon, never known before or since, was due to these facts. Lake Erie was full of floating ice flowing to its outlet, the source of Niagara River. During the previous afternoon a heavy northeast wind had driven the ice back into the lake, and during the night the wind, suddenly veering, blew a gale from the west which forced the ice floe sharply into a mass in the narrow channel of the river, where it froze. Thus, when the water on the lower side of the barrier drained off, the Niagara River and the American Fall were dry, and the Canadian Fall a mere trickle. This extraordinary condition lasted for a whole day.
Thus the descent of this stream at the Falls and in the Rapids just above them gives in theory a water-power of nearly 4,000,000 lip., three-fourths of which is estimated as available.
This maximum could be obtained only by sacrificing the beauty of the Falls—in fact diverting the river from its channel so that the cataract as a scenic feature would be destroyed. To combat this commercial vandalism an association for the protection of the Falls has been formed.
There were before 1918 several companies with power-producing plants, the largest of which was the Niagara Falls Hydraulic Power and Manufacturing Company.
This company had made an extensive beginning in utilization of the water fall by a tunnel 29 ft. deep and 18 ft. wide, passing about 200 ft.. below the surface of the city from a point 1¼ M. above the Falls to the upper steel arch bridge.
In 1918, when added power was needed for the more rapid production of war materials, the various companies consolidated with the Niagara Falls Power Company. In May of that year the intake from the Niagara River and the hydraulic canal were deepened, and three hydro-electric units—the largest in the world today—were installed, with the result that an extension of 100,000 hp. was developed, making the total of the station 250,000 hp.