exhibit incontestable signs, that their jagged perpendicular walls were once in junction. Every Mexican traveller must have remarked the insidious manner in which many of these gulfs commence. In riding along the plains, you perhaps find yourself separated from the companion with whom you are conversing, by a crack or fissure of a few inches in breadth: you proceed carelessly; the rent gapes imperceptibly wider and wider; and increases in depth, till it imperatively demands your attention. Perhaps a very natural dislike to retrace your steps, and ignorance of the real nature and extent of the obstacle, induces you to keep your direction in search of its termination; when, before you are aware, you find a hideous and impassable gulf yawning between you, delving deep for many miles into the face of the landscape, and no alternative left you but to return to its very source. I sketch from experience. Some of the largest barrancas I have described form beds for the scanty streams descending from the forested slopes of the neighbouring cordillera, and at one of these, about ten in the morning, we quenched for a moment the burning thirst of our party, men and horses.
An hour after, we reached the base of the hills which apparently form a detached group in the table land. For many miles previously we had observed and repeatedly crossed an ancient paved causeway, about eight feet in breadth, composed of large stones tightly wedged together, and running directly over plain and barranca, towards the hill of Xochicalco.
The strange mould of the summit of the steep hill on our left, as we entered the group by a small valley, had long drawn our attention, as it appeared to be surrounded by a regular rampart; but I incline to think that it may be the natural formation.
At the termination of the little valley above mentioned, we arrived at length at the foot of the eminence which was the principal object of our excursion.
The circuit of the hill of Xochicalco, or the House of Flowers, may perhaps measure three miles, and its per-
