covered continent, are frequented by enormous
timber rafts, commonly borne along by the force
of the current alone, though sometimes acceler-
ated by spreading a sail, or by huge oars called
sweeps. These floating islands of timber, with
huts here and there rising upon their low surface
for the accommodation of the raftmen, and also
another sort of craft with long, low hulls, no-
where else known, and designed for the transpor-
tation of timber of great length, contribute the
more remarkable and picturesque features to the
animating spectacle presented by the navigation
upon this noble river. The navigation is, of
course, obstructed by the ice in winter, which in
this high latitude continues, either bound or
floating, for several months. Erom Montreal to
Lake Ontario the navigation of the river is fre-
quently interrupted by falls and rapids, which
has occasioned the construction, at a heavy ex-
pense, of a series of canals, with locks of suffi-
cient dimensions to admit the passage of the
largest steamboats, and of the vessels navigating
the St. Lawrence from Quebec to Montreal. The
line commences with the Lachine Canal, extend-
ing from Montreal to the village of Lachine,
round the rapids of the same name, a distance of
8 miles. Erom Lachine, the river, or a broad
expansion of it, called Lake St. Louis, is naviga-
ble to the cascades, at the mouth of the Ottawa
River. Here commences the Beauharnois Canal,
which extends 16 miles, to a point opposite to
Coteau du Lac, surmounting the obstacles caused
by the several rapids known as the Cascades, the
Cedars, and the Coteau du Lac, which make, in
all, a difference of elevation of about 60 feet. At
this point another expansion of the river is
entered, called Lake St. Francois, which reaches
to Cornwall, a distance of 40 miles, in 45° lat.
The St. Lawrence Canal commences at this
point, and extends to Dickinson's Landing, 12
miles, passing the Long Sault Rapids, which
have a total descent of about 50 feet. This
canal, which is a fair sample of all the other
works, has 6 locks, of solid masonry, con-
structed in the most durable manner, each 200
feet long in the chamber, by 50 feet wide, with a
depth of 10 feet. Erom Dickinson's Landing to
Lake Ontario, steamers of a large class navigate
the river, though there are two or three rapids
below Ogdensburg. The Welland Canal, which
unites the waters of Lake Ontario and Lake
Erie, by affording a navigable channel round the
Falls of Niagara, is a work of great magnitude.
It is 42 miles long, 56 feet wide, and 16 feet
deep; and the whole ascent from one lake to
the other is 334 feet. To accomplish this ascent
there are 22 locks, constructed of granite, with a
lift of from 12£ to 14 feet. Those at each en-
trance from the lakes are 185 feet long and 45
feet wide. The others are 150 feet long and 46£
feet wide. This canal has one deep cut through
a mountain ridge, 45 feet deep, where an im-
mense quantity of earth and rocks was removed.
This work was first completed in 1829, at a cost
of $1,000,000; but in 1845 and 1846, it was en-
larged and improved at a great additional ex-
pense. All the above-mentioned canals are on
the Canadian side of the river, and are the prod-
uct of British capital and enterprise, designed
to furnish a continuous ship navigation through-
out the whole extent of the valley of the St.
Lawrence, and the basin of the great lakes, to
the Falls of St. Mary, and to give to the Canadas
a direct and independent communication be-
tween the vast and far north-west and the Atlan-
tic Ocean.

St. Louis River, Ma. The head branches of
this river rise in Dead Fish and Seven Beaver
Lakes; it then flows S. W. for some distance,
and finally flows S. E., forming the boundary be-
tween Wn. and Ma. until its entrance into Lake
Superior.

St. Lucra Sound, St. Lucie co., Fa., extends
from Gilbert's Bar, parallel with the coast, to
Indian River.

St. Mark's River, Fa., rises in a small pond,
and after a S. W. course of 19 miles, unites with
Wakully River at St. Mark's, to form the Ap-
palaehee. Boats requiring 4 feet of water as-
cend its whole length.

St. Martin's River, Md., waters the N. E. part
of Worcester co., and enters the Atlantic through
Sincpuxent Bay, opposite Fenwick's Island.

St. Mary's River, St. Mary's co., Md. It rises
near the mouth of the Patuxent River, and flows
S. into the Potomac.

St. Mary's River, Ga. and Fa. This river,
which was formerly the boundary of the United
States, rises in Okefinokee Swamp, in the S.
part of Ware co., Ga., and flowing S. for some
distance, it suddenly turns N., and finally takes
an E. course until its entrance into the Atlantic.
It is 105 miles long, at low tide has 13£ feet of
water on the bar, and at common high tide 19^
feet. It forms the only good harbor of the E.
coast of Fa.

St. Mary's River, O. and la., rises in the S.
part of Mercer co., O., flows N. W., and unites
with St. Joseph's River to form the Maumee at
Fort Wayne.

St. Mary's Strait forms the outlet of Lake Su-
perior, and its connection with Lake Huron. It
is about 70 miles long from Maple Isles, in Lake
Superior, to the passage between Drummond's
and St. Joseph's Islands, into Lake Huron
proper. The strait is naturally divided into two
sections by the Falls of St. Mary, about 30 miles
below Lake Superior. The upper section is
chiefly free from islands, and gradually contracts
in width to about half a mile at the point where
it rushes down the falls. This part of the strait
is navigable for vessels drawing 6 feet of water.
The Falls of St. Mary consist of a rapid descent
over ledges of rocks, without any perpendicular
fall, for about three fourths of a mile. It is as-
certained that the rocky barriers of this narrowest
part of the strait are gradually yielding to the
abrasion of the waters and the ice, and that the
surface of Lake Superior is lowering. Below
the Falls the channel of the strait or river be-
comes wider, and is soon divided into two by
George's Island, which division is continued by
St. Joseph's Islands below quite to the entrance
into Lake Huron. On the American side, the
channel, which is again subdivided by Sugar
Island, 20 miles long, and others of smaller size,
forms the more direct entrance into Lake Huron,
by a passage between the westernmost of the
Manitou Islands and the promontory of the True
Detour, from the Michigan shore. The other
channel, on the Canada side, terminates in the
Manitou Bay of Lake Huron, upon the N. side of
the Manitou Islands. The entire fall from the
level of Lake Superior is 23 feet. Vessels with
a draught of 6 feet may go up from Lake Huron
to Sault de St. Mary at the foot of the Falls.