Ottawa (river). A river of Canada, separating the provinces of Quebec and Ontario. It takes its rise in a lake in the high land between the St. Lawrence and Hudson Bav. and, after a course of 300 miles N.E. to S.W., flows S.E. for 400 miles, forming on the way the Lake of Two Mountains, and falls into the St. Lawrence at St. Anne's Rapids, which begin six miles above Ottawa city, and have a drop of forty feet at Chaudiere Falls. The river is navigable to these falls, and the rapids are passed by means of the Rideau Canal. The city, the capital of Canada, is in the province of Ontario, on the right bank of the river Ottawa, 100 miles west of Montreal. It is on the Canadian Pacific Railway, and is divided into Upper and Lower town by the Rideau Canal, which is crossed by a stone bridge. The city is well built and laid out, and has fine Government buildings which cover four acres, and the first stone of which was laid by the Prince of Wales in 1860. Rideau Hall in the neighbourhood is the residence of the Governor-General. There is a considerable lumber trade, and some manufactures. The town used to be called Bytown, after Colonel By, who founded it in 1827. The name was changed in 1854, and Ottawa became capital of Canada in 1858.