Beyond Esmeralda several travellers, from the time of Don Francisco de Bobadilla downwards, have reached the Raudal de los Guaharibos, but all have been compelled to turn back from those rapids, on account of the ferocity of the Indians of that name. Only one traveller claimed to have been more fortunate than the rest and to have reached the source of the great river. The Guaharibo Rapids are situated some 120 miles up-stream from Esmeralda.
The Ventuari is the largest Venezuelan tributary of the Upper Orinoco, yet the three hundred miles or so of its course are practically unknown to Europeans. As far as its valley has been explored, alternating forests and savannahs have been found. Across these in colonial times there was once a track uniting Esmeralda directly with the Lower Orinoco by way of the Caura; the route lay up the Padamo and then across the head-waters of the Ventuari to the source of the Erewato, a tributary of the Caura. Along this road there was a chain of forts, but the cruelties of the soldiers at last led the Indians to unite for their examination, and Humboldt tells us that every man in the fifty-league-long chain of forts was slain one night in 1776. The Indians told him that by this road it was ten days from Esmeralda to the headquarters of the Ventuari, and two days thence to the mouth of the Erewato.
Some of the upland savannahs which this road crossed must be excellently situated both for occupation by Europeans and for stock-raising, but the region is naturally very difficult of access at present, lying as it does in the very back of the hinterland of the Guayana. These districts are occupied by the Maquiritare, near relatives of, if not identical with, the Waiomgomo of the Caura. Their territory produces rubber and timber as well as gold. Auriferous quartz is said to have been seen by casual traders up the Ventuari, and the inhabitants collect the precious metal, storing it in jars, with which, by devious waterways and many portages, they travel across to British Guiana to trade for rifles of a quality unobtainable in southern Venezuela.
Separated by a narrow ridge from the Ventuari is the upper valley of the Merevari (Caura), a practically unknown region, scantily peopled by the Waiomgomo, and apparently possessing no particular attractions from a commercial point of view.
On the south side of the main river we have one of the most notable instances of a natural phenomenon peculiar to the elevated inland plain of South America in the celebrated bifurcation of the Casiquiare, some twenty miles below Esmeralda. The watershed between the Orinoco and the Rio Negro is here very ill defined, and near the bifurcation a line of slight elevation on the southern bank of the former river is all that exists to separate the two great drainage systems. At the head of the Casiquiare the elevation is sufficiently reduced to allow some part of the water of the Orinoco to overflow into the southern drainage area, and so affords a through waterway to the whole of the Amazon Valley.
On the eastern side of the Brazo, as it is called, there are numerous tributaries, whose upper courses are absolutely unknown, save from the casual reports of wandering Indians. The main stream and its affluents alike flow through great forests, and the immediate neighbourhood of the Casiquiare being level, the valley is damp and abounds in small lakes and swamps.
There is abundant rubber in the forests, but the life of the inhabitants of the small settlements, which are mainly supported by this industry, is a miserable one. They live chiefly on cassava, accompanied by much alcohol in one form or another, from champagne to raw sugar spirit; if other beverages fail, they have even fallen back on eau-de-Cologne, brought from Pará or Ciudad Bolivar and, one would have imagined, too expensive a luxury to be imbibed in quantity.
The Casiquiare discharges its waters into the Guainia, or more correctly, the two streams join to form the Rio Negro, the river being known by that name below the junction. The highest village of importance on the Guainia is Maroa, the seat of government of the Rio Negro district. The Guainia being a clear, deep (i.e., black) stream, with a cloudless sky overhead and no mosquitoes, Maroa enjoys a good climate. Its inhabitants cultivate an excellent quality of manioc and manufacture hammocks.
The forests of the Guainia and Rio Negro are comparatively little known, though some rubber is collected along the banks. The old settlement of San Carlos, on the Rio Negro, is now abandoned, and beyond this there are no Venezuelan villages before the hill known as the Cerro del Cucuhy, which marks the Brazilian frontier, and beyond lies the military station of Cucuhy, occupied by soldiers of the latter republic.
Although, as we have seen, it is possible to travel by water from the Orinoco to the Amazon, the more direct route up the Atabapo and across the “Isthmus” of Pimichin to the Guainia is generally used by the Indians and traders.