Besides the great stream of Niagara, many rivers flow into Ontario both on the Canadian and American sides. The bays and harbors are also very numerous, affording great facilities for navigation and commerce: in this respect the northern shore is the most favored--the Bays of Quinte and Burlington are especially remarkable for their extent and security.[139] The northeast end of Lake Ontario, where its waters pour into the St. Lawrence, is a scene of striking beauty;[140] numerous wooded islands, in endless variety of form and extent, divide the entrance of the Great River[141] into a labyrinth of tortuous channels, for twelve miles in breadth from shore to shore: this width gradually decreases as the stream flows on to Prescot, fifty miles below; a short distance beyond that town the rapids commence,[142] and thence to Montreal the navigation is interrupted for vessels of burden; boats, rafts, and small steamers, however, constantly descend these tumultuous waters, and not unfrequently are lost in the dangerous attempt. The most beautiful and formidable of these rapids is called the Cedars, from the rich groves of that fragrant tree covering numerous and intricate islands, which distort the rushing stream into narrow and perilous channels: the water is not more than ten feet deep in some places, and flows at the rate of twelve miles an hour. The river there widens into Lake St. Francis, and again into Lake St. Louis, which drains a large branch of the Ottawa at its south-western extremity. The water of this great tributary is remarkably clear and of a bright emerald color; that of the St. Lawrence at this junction is muddy, from having passed over deep beds of marl for several miles above its entrance to Lake St. Louis: for some distance down the lake the different streams can be plainly distinguished from each other. From the confluence of the first branches above Montreal these two great rivers seem bewildered among the numerous and beautiful islands, and, hurrying past in strong rapids, only find rest again in the broad, deep waters many miles below.