The trees of the forest, as in the basin of the latter river, advance as far as the beach, and there form a thick coppice; but the Cassiquiare has white waters, and more frequently changes its direction. Its breadth, near the rapids of Uinumane, almost surpasses that of the Rio Negro. I found it everywhere from two hundred and fifty to two hundred and eighty toises, as far as above Vasiva.
The ground rises towards the south; for Truxillo, the lake of Urao, from which carbonate of soda is extracted, and La Grita, all to the east of the Cordillera, though no farther distant, are four or five hundred toises high.
Hieroglyphic figures, and even characters in regular lines, are seen sculptured on their sides; though I doubt whether they bear any analogy to alphabetic writing. On measuring the breadth of the Orinoco between the islands called Isla de Uruana and Isla de la Manteca, we found it, during the high waters, 2674 toises, which make nearly four nautical miles.
This last mountain is 540 toises higher than the volcano of Teneriffe; and if, notwithstanding this difference, the sky is observed there to be of a less deep blue, we must attribute this phenomenon to the dryness of the African air, and the proximity of the torrid zone. We collected on the brink of the crater, some air which we meant to analyse on our voyage to America.
The temperate table-lands and real chains of 300 to 500 toises high have been confounded with countries of exceedingly hot temperature, and of which the undulating surface presents only ranges of hills variously grouped. But the observations of scientific travellers have recently thrown great light on the orography of Portuguese America.
This road is cut out of a talcose gneiss* in a state of decomposition. Travellers suffer from the dust in winter, while in the rainy season the place is changed into a slough. On descending the table-land of Buenavista, about fifty toises to the south-east, an abundant spring, gushing from the gneiss, forms several cascades surrounded with thick vegetation.
The city of Caracas is seated at the entrance of the plain of Chacao, which extends three leagues eastward, in the direction of Caurimare and the Cuesta de Auyamas, and is two leagues and a half in breadth. This plain, through which runs the Rio Guayra, is at the elevation of four hundred and fourteen toises above the level of the sea.
It is nevertheless highly interesting both to agriculture in the colonies and meteorology, and fully as important as the measure of the limit of the perpetual snows. My observations furnished me with the data, set down in the following table: Column 1: North latitude. Column 2: Lowest height in toises at which snow falls. Column 3: Lowest height in metres at which snow falls.
We were at nine hundred and forty toises of elevation; and yet at the same height, towards the east, we perceived in a ravine, not merely a few solitary palm-trees, but a whole grove. It was the palma real; probably a species of the genus Oreodoxa.
This rapid descent greatly amused us, and we were only stopped by the mud which succeeded the snow at the distance of five or six hundred toises down the declivity. We crossed, or rather climbed up, Mont Albaredo to avoid passing under the fort of Bard, which closes the valley of Aorta.