16 AMAZONIA AND LA PLATA. 



But tliis o-reat 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 twelve miles seawards, is explained 

 by the great extent of its catchment basin, combined with an abundant rainfall 

 and the impermeable character of the soil. During the winter season the upper 

 reaches, dammed up by their rocky barriers, overflow their banks in many places, 

 thus periodically restormg the chain of lakes which at one time existed in the 

 fluvial valley. 



The Demerara, Berbice, asb Corentyne. 



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. Eising 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 

 with sandhills from 50 to 60 f-eet 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 tbey 

 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 Eiver, 

 through a labyrinth of ramifying branches, and below the confluence the united 

 waters descend to the plains through a series of superb fulls and rapids. To one 

 of these, Robert Schomburgk gave the name of King Frederick AVilliam 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 estuary, studded with islands, reefs, and shoals, 

 is of difiicult access, and practically closed to vessels drawing more than 10 feet 

 of water. 



