Viewing, between the parallels of 34 degrees and 27 degrees, a vast area
of depressed interior, subjected in seasons of prolonged rains to partial
inundation, by a dispersion of the several waters that flow upon it from
the eastern mountains whence they originate; and bearing in mind at the
same time, that the declension of the country within the above parallels,
as most decidedly shown by the dip of its several rivers, is uniformly
to the N.N.W. and N.W., it would appear very conclusive, that either a
portion of our distant interior is occupied by a lake of considerable
magnitude, or that the confluence of those large streams, the Macquarie,
Castlereagh, Gwydir, and the Dumaresq, with the many minor interfluent
waters, which doubtless takes place upon those low levels, forms one
or more noble rivers, which may flow across the continent by an almost
imperceptible declivity of country to the north of north-west coasts, on
certain parts of which, recent surveys have discovered to us extensive
openings, by which the largest accumulations of waters might escape to the
sea."

CHARACTER OF THE RIVERS.

It is the characteristic of the streams falling westerly from the eastern,
or coast ranges, to maintain a breadth of channel and a rapidity of
current more immediately near their sources, that ill accords with their
diminished size, and the sluggish flow of their waters in the more
depressed interior. In truth, neither the Macquarie nor the Castlereagh
can strictly be considered as permanent rivers. The last particularly is
nothing more than a mountain torrent. The Macquarie, although it at length
ceased to run, kept up the appearance of a river to the very marshes; but
the bed of the Castlereagh might have been crossed in many places without
being noticed, nor did its channel contain so much water as was to be
found on the neighbouring plains.

There are two circumstances upon which the magnitude, and velocity of a
river, more immediately depend. The first is the abundance of its sources,
the other the dip of its bed. If a stream has constant fountains at its
head, and numerous tributaries joining it in its course, and flows withal
through a country of gradual descent, such a stream will never fail; but
if the supplies do not exceed the evaporation and absorption, to which
every river is subject, if a river dependant on its head alone, falls
rapidly into a level country, without receiving a single addition to its
waters to a