The universal geography : earth and its inhabitants

16
AMLiZONIA AND LA PLATA.
But ttis great expanse is broken and divided into three main navigable branches
by a number of islands, whose long axes are disposed in the same direction as the
tidal currents.
The enormous volume of water which is discharged by the Essequibo, and
which makes itself felt at a distance of some twelvo miles seawards, is explained
by the great extent of its catchment basin, combined with an abundant rainfall
and the impermeable character of the soil. Daring the winter season the upper
reaches, dammed up by their rocky barriers, overflow their banks in many places,
thus periodically restoring the chain of lakes which at one time existed in the
fluvial valley.
The Demerara, Berbice, and Corestyne.
The Demerara (Demerari), formerly Lemdrare, flows east of and parallel to
the Essequibo with such regularity that it might almost be taken for a lateral
channel, into which were formerly discharged the flood waters of some stream
rivalling the Amazons itself in magnitude. Rising amid the northern spurs of
the dividing range, the Demerara traverses the same geological formations as the
Essequibo, first granite masses, then sandstones with diorites cropping out at
various points, and towards the coast broad alluvial tracts strewn here and there
wilh sandhills from 50 to 60 feet high. Sluggish channels and backwaters ramify
eastwards, connecting the Demerara with the Mahaica, a river of similar aspect,
but of much smaller volume.
The Berbice and the Corentyne (Corentijn), which follow in the direction of
the east, also flow in parallel courses quite as regular as those of the Essequibo and De-
merara. They develop the same curves and have to surmount the same obstructions
by cascades tumbling over rocky granite, diorite, or sandstone barriers. But they
vary considerably in length, the Berbice rising far in advance of the dividing
range, whereas the Corentyne has its source in the Curucuri mountains away to
the south. The latter is already a copious stream at the point where it pierces the
rocky hills, in which its western neighbour the Berbice takes its rise.
In this district the Corentyne is joined on its left bank by the New River,
through a labyrinth of ramifying branches, and below the confluence the united
waters descend to the plains through a series of superb falls and rapids. To one
of these, Robert Sehoniburgk gave the name of King Frederick William the
Fourth, as to the corresponding cataract of the Essequibo, which lies under the same
latitude, and which presents the same general aspect amid its rugged granite walls.
The Corentyne develops another grand fall at the crystalline rocks of Wonotobo,
where three or four branches ramifying into several channels are precipitated
from a height of about 100 feet into a lake about a mile wide, from which it
issues in a single stream about 1,000 feet broad and 80 feet deep. Beyond this
point the Corentyne is entirely free from rapids for the rest of its course of some
170 miles to the sea. But its broad cstuar}% studded with islands, reefs, and shoals,
is of difficult access, and jDractically closed to vessels drawing more than 10 feet
of water.