Saint Lawrence, a river and gulf of North America. The river proper begins at Kingston, at the foot of Lake Ontario, and flows N. E., first between New York and Ontario, Canada, and then through the province of Quebec, about 750 m., to the gulf. It insensibly expands into the gulf, but is usually considered as terminating between Cape Chatte on the south and Pointe des Monts on the north, about lat. 49° 15' N., lon. 67° W. At its issue from Lake Ontario it is 2 1/2 m. wide, and in the narrowest parts its width is seldom less than 2 m. Below the city of Quebec it gradually expands, and at its mouth is upward of 30 m. wide. At Cape Gaspé the gulf is nearly 100 m. wide. The principal expansions above Quebec are Lake St. Peter, 30 m. long and 10 m. wide, just above Three Rivers; that containing the island of Montreal, Isle Jésus, and Isle Perrot; Lake St. Francis, a little further up; and the Lake of the Thousand Islands, near its issue from Lake Ontario, containing the celebrated Thousand islands. The principal island below Quebec is the isle of Orleans. The influence of the tide is felt as high up as Lake St. Peter. Its principal tributaries on the N. side are the Ottawa, the St. Maurice, the Saguenay, and the Betsiamite or Bersimis; those on the S. side, which are smaller and of less importance, are the Oswegatchie, Grass, Raquette, St. Regis, Sorel (also called the Richelieu, Chambly, or St. Johns), St. Francis, and Chau-dière rivers.
The St. Lawrence drains a territory of over 400,000 sq. m., and its basin, reckoned from its extreme source, was computed by Darby, before the discovery of the great African lakes, to contain "more than half of all the fresh water on this planet." Early French geographers, treating the great lakes as expansions of the stream, made the river Nipigon, on the N. side of Lake Superior, the head stream of the St. Lawrence. Others have considered as such the St. Louis river, emptying into the S. W. extremity of Lake Superior. In either case the total length would be upward of 2,000 m. Besides Lakes Ontario, Erie, St. Clair, Huron, Michigan, and Superior, there is a number of lakes N. and W. of Lake Superior, which together would about equal Lake Ontario. These all pour their waters into the ocean through the St. Lawrence. Regarding the chain as one stream, between Lakes Superior and Huron it is known as the St. Mary's river; between Huron and St. Clair as the St. Clair river; between St. Clair and Erie as the Detroit river; and between Erie and Ontario as the Niagara river. The St. Lawrence is navigable by sea-going vessels to Montreal. Above that city its navigation is impeded by rapids, of which the Cedar and Lachine are the most considerable.
The inclination of these rapids is so regular, that steamboats drawing 7 ft. of water can descend the river safely; and for the purpose of obviating the difficulty of ascent (Lake Ontario being 231 ft. above the ocean level according to former measurements, and according to J. T. Gardner's recent calculations several feet higher), seven different canals have been constructed, of an aggregate length of 41 m., which will admit the passage of vessels of 1,000 tons. A canal has also been constructed from Lake Ontario to Lake Erie, called the Welland canal, 28 m. in length, and having capacity to pass a vessel of 500 tons burden. There is also a ship canal of large size around the falls of St. Mary, between Lake Huron and Lake Superior. A vessel of 500 tons may load from the mouth of the St. Louis river at Duluth, Minn., or from Chicago, and, without breaking bulk, pass down the St. Lawrence to any port in the world. An enlargement of the St. Lawrence and Welland canals is now (1875) in progress. When this is completed, the locks will each have 270 ft. of chamber, with a width of 45 ft., and a depth of 14 ft. over the mitre sills.
The enlargement was at first intended to give only 12 ft. of water, and to obtain this depth the official estimate of cost was $10,000,000. From one third to one fourth of the vessels employed on the upper lakes are too large to pass through the existing Welland canal into Lake Ontario; the enlarged canals, which may be ready for the season of 1880, will be able to pass the largest vessels used on those waters. Enormous as is the water supply of the St. Lawrence canals, it is subject to considerable periodic changes of level; and the proposed 14 ft. of water in them is estimated from the lowest levels that have been reached in 55 years, during which the difference between the highest and the lowest levels has been 5 1/2 ft. in Lake Ontario; and to secure the required depth it is intended to sink the locks 15 ft. below the low-water mark. The annual rise is from 10 to 20 in.; but besides this there is an irregularly recurring change of level, extending over a series of years, which cannot be calculated.
The number of days during which the canals have been open during the past 24 years has varied, in the case of the Lachine canal, from 197 to 233, the average probably being 220; of the Beau-harnois, from 209 to 229, with an average a little higher than the Lachine. In 1874,1,000,-573 tons of shipping passed through the St. Lawrence canals, and 1,389,173 tons through the Welland. - The gulf of St. Lawrence, which receives the waters of this mighty river, is bounded N. by Labrador, E. by the islands of Newfoundland and Cape Breton, S. by Nova Scotia, and W. by New Brunswick and Quebec. It has an estimated area of 80,000 sq. m. It has three channels of communication with the ocean, viz., between Newfoundland and Cape Breton, by the strait of Belle Isle on the north, and through the gut of Canso on the south. It has numerous islands, among which the largest are Anticosti, Prince Edward, and the Magdalen group. Its principal bays are those of Chaleurs, between New Brunswick and Quebec; Miramichi, in New Brunswick; St. George, in Nova Scotia; and St. George's, in Newfoundland.
Saint Lawrence, a N. county of New York, bordered N. W. by the' St. Lawrence river, drained by the Indian, Oswegatchie, Grass, Raquette, St. Regis, and Deer rivers and their affluents, and traversed by several railroads; area, 2,900 sq. m., being the largest county in the state; pop. in 1870, 84,826. It has three lakes of considerable size, Long, Black, and Cranberry, besides several smaller ones. The southern portion of the county is as yet but thinly settled, and is heavily timbered. Along the St. Lawrence the surface is generally level and very productive. There are mines of lead and specular iron ore. The chief productions in 1870 were 569,701 bushels of wheat, 35,295 of rye, 174,840 of Indian corn, 1,077,345 of oats, 196,421 of barley, 57,078 of buckwheat, 1,217,894 of potatoes, 269,250 tons of hay, 281,962 lbs. of wool, 8,419,695 of butter, 1,710,082 of cheese, 157,275 of hops, 104,266 of flax, 1,063,592 of maple sugar, and 23,283 of honey. There were 24,126 horses, 87,293 milch cows, 1,612 working oxen, 31,693 other cattle, 62,632 sheep, and 16,981 swine; 4 manufactories of agricultural implements, 8 of pot and pearl ashes, 10 of brick, 46 of carriages and wagons, 20 of cheese, 8 of iron castings, 26 of tanned and 20 of curried leather, 9 of machinery, 30 of saddlery and harness, 9 of starch, 19 of tin, copper, and sheet-iron ware, 11 of wooden ware, 8 of woollen goods, 7 wool-carding and cloth-dressing establishments, 25 flour mills, 97 saw mills, and 3 planing mills.