Below the island of Montreal the St. Lawrence continues, in varying breadth and considerable depth, to Sorel, where it is joined by the Richelieu River from the south; thence opens the expanse of Lake St. Peter, shallow and uninteresting; after twenty-five miles the Great River contracts again, receives in its course the waters of the St. Maurice, and other large streams; and 180 miles below Montreal the vast flood pours through the narrow channel that lies under the shadow of Quebec.[147] Below this strait lies a deep basin, nearly four miles wide, formed by the head of the Island of Orleans: the main channel continues by the south shore. It would be wearisome to tell of all the numerous and beautiful islands that deck the bosom of the St. Lawrence from Quebec to the Gulf. The river gradually expands till it reaches a considerable breadth at the mouth of the Saguenay. There is a dark shade for many miles below where this great tributary pours its gloomy flood into the pure waters of the St. Lawrence: 120 miles westward it flows from a large, circular sheet of water, called Lake St. John; but the furthest sources lie in the unknown regions of the west and north. For about half its course, from the lake to Tadoussac at the mouth, the banks are rich and fertile; but thence cliffs rise abruptly out of the water to a lofty height--sometimes 2000 feet--and two or three miles apart. The depth of the Saguenay is very great, and the surrounding scenery is of a magnificent but desolate character. Below the entrance of the Saguenay the St. Lawrence increases to twenty miles across, at the Bay of Seven Islands to seventy, at the head of the large and unexplored island of Anticosti to ninety, and at the point where it may be said to enter the Gulf between Gaspe and the Labrador coast, reaches the enormous breadth of 120 miles. In mid-channel both coasts can be seen; the mountains on the north shore rise to a great height in a continuous range, their peaks capped with eternal snows. Having traced this vast chain of water communication from its remotest links, it is now time to speak of the magnificent territory which it opens to the commerce and enterprise of civilized man.