ising the borders of the stream, by
intercepting the drift sand which the wind sweeps from the margin of the
shallow ponds as they dry up in summer. The banks, being firmly frozen
in spring, are enabled to resist the weight of the temporary floods
which occur in that season, and before they are thawed the river has
resumed its low summer level. The trees which grow on the islands
terminate suddenly, in lat. 68 degrees 40 minutes.

I have already mentioned, that a large sheet of brackish water, named
Esquimaux Lake, lies to the eastward of the Rein-deer Mountains, running
to the southward, and approaching within sixty miles of the bend of
Mackenzie's River at Fort Good Hope. This lake has a large outlet into
Liverpool Bay, to the westward of Cape Bathurst, and there are many
smaller openings betwixt that bay and Point Encounter, near the north
end of the Rein-deer Hills, which are also supposed to form
communications betwixt the lake and the sea. The whole coast-line from
Cape Bathurst to the mouth of the Mackenzie, and the islands skirting
it, as far as Garry and Sacred Islands, present a great similarity in
outline and structure. They consist of extensive sandy flats, from which
there arise, abruptly, hills of an obtuse conical form, from one to two
hundred feet above the general level. Sandy shoals skirt the coast, and
numerous inlets and basins of water divide the flat lands, and
frequently produce escarpments of the hills, which show them to be
composed of strata of sand of various colours, sometimes inclosing very
large logs of drift timber. There is a coating of black vegetable earth,
from six inches to a foot in thickness, covering these sandy hummocks,
and some of the escarped sides appeared black, which was probably caused
by soil washed from the summit.

It is possible that the whole of these eminences may, at some distant
period, have been formed by the drifting of moveable sands. At present
the highest floods reach only to their bases, their height being marked
by a thick layer of drift timber. When the timber has been thrown up
beyond the reach of ordinary floods, it is covered with sand, and, in
process of time, with vegetable mould. The _Elymus mollis_, and some
similar grasses with long fibrous roots, serve to prevent the sand-hills
from drifting away again. Some of the islands, however, consist of mud
or clay. Captain Franklin describes Garry's Island as presenting cliffs,
two hundred feet high, of bla