The Niagara River is the channel by which all the waters of the lakes flow toward the Gulf of St. Lawrence. It has a total descent of 330 feet. The interruption to navigation occasioned by the rapid descent of the Niagara River is overcome on the Canadian side by the Welland Canal; on the American side the communication between tide-water and the upper lakes was first effected by the Erie Canal. The river flows in a northerly direction with a swift current for the first two miles and then more gently, with a widening current, which divides as a portion passes on each side of Goat Island. As these unite below the island the stream spreads out, about two or three miles in width, and appears like a quiet lake studded with small, low islands. About sixteen miles from Lake Erie the river grows narrow and begins to descend with great velocity. This is the commencement of the rapids, which continue for about a mile, the water falling in this distance about fifty-two feet. The stream terminates below in a great cataract. At this point the river, making a curve from west to north, spreads out to an extreme width of 4,750 feet. Goat Island, which extends down to the brink of the cataract, occupies one-fourth of this space, leaving the river on the American side about 1,100 feet wide and on the Canadian side about double this width. A cave, called the Cave of the Winds, is formed behind the fall, into which, on the Canadian side, persons can enter and pass by a rough and slippery path toward Goat Island. As already stated, there are many cataracts which descend from greater heights. The sublimity of Niagara is in the vast power displayed by a mighty current flowing down the long rapids and finally plunging in one uniform sheet into the abyss below. Dangerous as it appears, the river is here crossed by small rowboats. For seven miles below the falls the narrow gorge continues, varying in width from 200 to 400 yards. The river then emerges at Lewiston, N. Y., having descended 104 feet from the foot of the cataract. A suspension bridge was constructed in 1855 by Mr. Roebling, for the passage of railway trains, and eighteen feet below the railway it also sustains a carriage and foot track. From this bridge a fine view is had of the falls. Other bridges have since been built, among them a cantilever.