_Lake Superior_ is the largest body of fresh water in the world, being four hundred miles in length, one hundred at its greatest breadth, and, according to the most moderate computation, over twelve hundred miles in circumference. Its shores are rocky and uneven, and it has a rocky bottom. Its waters are pure and transparent, and it has been remarked, that, although during the summer, the waters on its surface be warm, nevertheless, by letting a cup down about a fathom, water may be taken up nearly as cold as ice. It abounds in fish, particularly sturgeon and long trout, many of which are from fifty to seventy pounds weight, and constitute the principal food of the Algonquin Indians on its borders. This lake has five large islands,[17] one of which, called _Isle Royal_, is not less than a hundred miles in length, and in some places forty in breadth. More than forty rivers discharge themselves into it, the two largest called the Nipegon and the Michipicooton, from the north and north-east sides. A small river which runs into it, not far from the Nipegon, falls from the top of a mountain more than six hundred feet perpendicular; appearing at a distance, to use Mr. Carver’s homely comparison, like a white garter suspended in the air. On the banks of one of the rivers which fall into its south side, virgin copper has been found. The storms which occur on this lake are felt as severely as on the Atlantic, the waves run equally high, and the navigation is perhaps more dangerous.[18] When the wind blows from the east, the waters are driven against the high rocks of the northern and western shores, where they form a thick vapor resembling rain; and this action of the wind creates an irregular ebb and flow. This never exceeds ten or twelve inches; but the strong traces of the water on the rocks of the shore show, that, at no very remote period, they were elevated six feet above the present level. Mackenzie states, that some years ago the waters suddenly withdrew near the Great Portage; then rushed back with great velocity above the common mark; and, after rising and falling during several hours, they settled at their usual level.