Respecting the immense torrent of water, which makes so prominent a figure in this eruption, a consi derable difference of opinion has arisen. Some ascribe it merely to the melting of the snow and ice by the flames; while others consider it as the effect of the subterranean fire upon certain reservoirs of water, which they suppose to be collected near the summit. The facts transmitted to us connected with this subject, are too few to enable us to give any judgment respecting this controversy. The form of this mountain is re markably regular, being that of a truncated cone; and its height, according to Condamine, is 2950 toises. Humboldt endeavoured to reach the summit, with the intention of examining the form of its crater, but was not able to succeed. The same author, however, con tradicts an opinion pretty general in the country, that this volcano has diminished in height since the great earthquake of 1797.
Next to Catopaxi, the most remarkable, perhaps, of all those volcanic mountains is Sangai; the southmost of the eastern ridge, to which it bears a striking resem blance in form, but is considerably inferior in height, being, according to Bouguer, only 2664 toises above the level of the sea. Ulloa represents this mountain as covered nearly in its whole extent of surface by perpe tual snow, and as subject in his time to incessant in flammation, the destructive effects of which are mani fest in the appearance of the surrounding plains, which are rendered completely barren by its ashes. But this volcano is distinguished from the rest, chiefly by the noises which it utters. These frightful sounds, accord ing to the statement of the author last quoted, are often so loud as to be heard at the distance of 40 leagues, as distinctly as in the immediate neighbourhood of the mountain. A similar account is given by Bouguer, who informs us, that while engaged at the station of Sene gualap, a distance of 20 miles, his sleep was continually interrupted daring the night by the bellowings of this volcano, which sometimes resembled the sudden crash of thunder; but more generally a deep hollow sound, which, by returning at short regular intervals, was pe culiarly annoying during the night.
Respecting Altair, in the immediate neighbourhood of Sangai and Ilinissa, in the middle of the western range, we have been able to obtain little information. They are by no mean§ remarkable for their height, and seem distinguished chiefly by their double summits. Cayamburo is described by Ulloa, as one of the loftiest mountains of the whole range, having its base encom passed by an extensive plain, remarkable for its cold ness and sterility. It has never exhibited any symp toms of a volcanic nature. Tunguragua has long been
famous for its hot baths, which are much frequented by all the people in the neighbourhood. The same re markable phenomena of hot springs are observed at a mountain to the south of Cuenza. Here the water rises to the top of the hill, where it is seen bubbling through orifices of five or six inches in diameter. This water is said by Ulloa to be so hot, that eggs are hardened in it sooner than in boiling water. Tunguragua is supposed to be a volcanic mountain, and is believed to have sunk down since the great earthquake of 1797. The different statements of Humboldt and Bouguer, respecting its height, seem to give some countenance to this opinion ; the latter makes its height to be 2620 toises, while the former found it to be only 2531, a difference of near 100 toises. The inhabitants of the neighbouring country, says Humboldt, assert, that they have seen its summit crumble down before their eyes.
But of all these mountains, the most prominent by far is Chimborazo, which is usually supposed to be the highest land on the globe. Several attempts have been made by travellers to reach its summit, but none, as far as we know, have yet been able to succeed. Humboldt, v e have reason to believe, is among the latest, and perhaps the most successful, of those who have en gaged in this arduous enterprise. He succeeded in approaching to within about 240 toises of the summit, by following a ridge of volcanic rocks, destitute of snow, which greatly facilitated his ascent. When lie reached the height of 3031 toises, he felt himself incommoded by the rarity of the air, in the, same manner as on the summit of Antesana; he resolved, however, to continue the journey, but unfortunately he soon after fell in with a fissure, which lie found himself unable to cross, and was therefore compelled to abandon the undertaking. The short stay, says this traveller, which we made at this enormous height, was dismal and melancholy ; we were enveloped by a thick fog, which only suffered us from time to time to have a glimpse of the horrid abys ses by which we were surrounded. No living creature, not even the condour, which hovered over our heads on Antesana, was to be seen. Small kinds of moss were the only organized beings which reminded us that we were still in the neighbourhood of the earth. The height of this mountain, by a trigonometrical measure ment of the same author, was found to be 3267 toises. It is probable, from the appearance of certain scorified rocks, mixed with pumice stone, which are found on different parts of its surface, that this mountain has for merly been subject to eruptions ; but nothing certain is known respecting this point.