From what I have already said, you will perceive that this volcano differs in one respect from most others of which we have accounts. The crater instead of being the truncated top of a mountain, distinguishable in every direction at a distance, is an immense chasm in an upland country, near the base of the mountain Monnaloa—approached not by ascending a cone, but by descending two vast terraces; and not visible from any point at a greater distance than half a mile, a circumstance, which, no doubt, from the suddenness of the arrival, adds much to the effect of a first look from the brink. It is probable that it was originally a cone, but assumed its present aspect, it may be centuries ago, from the falling in of the whole summit. Of this, the precipices we descended, which entirely encircle the crater in circumferences, of fifteen and twenty miles, give strong evidence. They have unquestionably been formed by the sinking of the mountain, whose foundations had been undermined by the devouring flames beneath. In the same manner one half of the present depth of the crater has at no very remote period been formed. About midway from the top a ledge of lava, in some places only a few feet, but in others many rods wide, extends entirely round, at least as far as an examination has been made; forming a kind of gallery—to which you can descend, in two or three places, and walk, as far as the smoke, settling at the south end, will permit. This offset bears incontestible marks of having once been the level of the fiery flood, now boiling[70] in the bottom of the crater. A subduction of lava, by some subterraneous channel, has since taken place, and sunk the abyss many hundred feet to its present depth. The gulf below contains probably not less than sixty—fifty-six have been counted—smaller conical craters, many of which are in constant action. The tops and sides of two or three of these are covered with sulphur, of mingled shades of yellow and green, with this exception, the ledge and every thing below it are of a dismal black. The upper cliffs, on the northern and western sides, are perfectly perpendicular, and of a red color, everywhere exhibiting the scarred marks of former powerful ignition. Those on the eastern side are less precipitous, and consist of entire banks of sulphur, of a delicate and beautiful yellow. The south end is wholly obscured by smoke, which fills that part of the crater, and spreads widely over the surrounding horizon. As the darkness of night gathered round us, new and powerful effect was given to the scene. Fire after fire, which the glare of mid-day had entirely concealed, began to glimmer on the eye with the first shades of evening, and as the darkness increased, appeared in such rapid succession, as forcibly to remind me of the hasty lighting of the lamps of a city on the sudden approach of a gloomy night. Two or three of the small craters nearest to us were in full action, every moment casting