ONTARIO, LAKE, the smallest and most easterly of the Great Lakes of North America. It hes between 43° 11' and 44° 12' N. and 76° 12' and 79° 49' W., and is bounded on the N. by the province of Ontario and on the S. by the state of New York. It is roughly eUiptical, its major axis, 180 m. long, lying nearly east and west, and its greatest breadth is 53 m. The area of its water surface is 7260 sq. m. and the total area of its basin 32,980 sq. m. Its greatest depth is 738 ft., its average depth much in excess of that of Lake Erie, and it is as a general rule free from outlying shoals or dangers.
On the north side of the lake the land rises gradually from the shore, and spreads out into broad plains, which are thickly settled by farmers. A marked feature of the topography of the south shore is what is known as the Lake ridge, or, as it approaches the Niagara river, the Mountain ridge. This ridge extends, with breaks, from Sodus to the Niagara river, and is distant from the lake 3 to 8 m. The low ground between it and the shore, and between the Niagara escarpment and the water on the Canadian shore, is a celebrated fruit growing district, covered with vineyards, peach, apple and pear orchards and fruit farms. The Niagara river is the main feeder of the lake; the other largest rivers emptying into the lake are the Genesee, Oswego and Black from the south side, and the Trent, which discharges into the upper end of the bay of Quinte, a picturesque inlet 70 m. long, on the north shore, between the peninsula of Prince Edward, near the eastern extremity of the lake, and the mainland. The east end of the lake, where it is 30 m. wide, is crossed by a chain of five islands, and the lake has its outlet near Kingston, where it discharges into the head of the St Lawrence river between a group of islands. Elsewhere the lake is practicaUy free from islands. There is a general surface current down the lake towards the eastward of about 8 m. a day, strongest along the south shore, but no noticeable return current. As a result of its relatively great depth there are seldom any great fluctuations of level in this lake due to wind disturbance, but the lake follows the general rule of the Great Lakes (q.v.) of seasonal and annual variation. Standard high water (of 1870) is 2-77 ft. below the mean level, of 246-18 ft. above mean sea-level, and standard low water 3-24 ft. below the same plane. The lake never freezes over, and is less obstructed by ice than the other lakes, but the harbours are closed by ice from about the middle of December to the middle of Aprfl.
The commerce of Lake Ontario is Hmited in comparison with that of the lakes above Niagara Falls, and is restricted to vessels that can pass through the Welland canal locks, which are 270 ft. long, 45 ft. wide and 14 ft. deep. Freight consists principally of coal shipped from Charlotte, Great and Little Sodus bays and Oswego to Canadian ports in the lakes, and to ports on the St Lawrence river; of grain shipped through the Welland canal to the St Lawrence; and of lumber from Canadian ports. There is a large passenger traffic, including pleasure trips, principally radiating from Toronto. Ports on the lake are limited in capacity to vessels drawing not more than 14 ft. of water. The principal Canadian ports are Kingston, at the head of the St Lawrence river; Toronto, where the harbour is formed by an island with improved entrance channels constructed both east and west of it; and Hamilton, at the head of the lake, situated on a landlocked lagoon, connected with the main lake by Burlington channel, an artificial cut. The principal United States port is Oswego, where a breakwater has been built, making an outer harbour. The construction of a breakwater was undertaken in 1907 by the United States government at Cape Vincent to form a harbour where westbound vessels can shelter from storm before crossing the lake.
The difference of 327 ft. in level between Lake Ontario and Lake Erie is overcome by the Welland canal, which leads southward from Port Dalhousie. It accommodates vessels 255 ft. in length, with a draught of 14 ft. The Murray canal, opened for traffic on the 14th of April 1890, extends from Presqu'ile bay, on the north of the lake, to the head of the bay of Quinte, and enables vessels to avoid 70 m. of open navigation. It is 11 ft. deep below the lowest lake level, and has no locks. It is proposed to have the eastern terminus of the Trent canal system (see Great Lakes) at the head of the bay of Quinte, entering through the Trent river. At Kingston the Rideau canal, extending 128 m. to Ottawa, enters the St Lawrence river at the foot of the lake.
Bibliography. - Bulletin No. 17, Survey of Northern and Northwestern Lakes, LI.S. Lake Survey Office (Detroit, Mich., 1907); Publication No. I08 D., Sailing Directions for Lake Ontario, Hydrographic Office, LT.S. Navy (Washington, D.C., 1902); St Lawrence Pilot (7th ed.), Hydrographic Office, Admiralty (London, 1906).
(W. P. A.)
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)