The Spaniards, on arriving before the city, the limit of their southerly progress, found themselves separated from it by one of the vast barrancas before noticed, which resembled one of those frightful rents not unfrequent in the Mexican Andes, the result, no doubt, of some terrible convulsion in earlier ages. The rocky sides of the ravine sank perpendicularly down, so bare as scarcely to exhibit even a vestige of the cactus, or of the other hardy plants with which Nature in these fruitful regions so gracefully covers up her deformities. The bottom of the chasm, however, showed a striking contrast to this, being literally choked up with a rich and spontaneous vegetation; for the huge walls of rock which shut in these barrancas, while they screen them from the cold winds of the Cordilleras, reflect the rays of a vertical sun, so as to produce an almost suffocating heat in the enclosure, stimulating the soil to the rank fertility of the _tierra caliente_. Under the action of this forcing apparatus,--so to speak,--the inhabitants of the towns on their margin above may with ease obtain the vegetable products which are to be found on the sultry level of the lowlands.{*} {*} [“The whole of this description,” remarks Alaman, “agrees perfectly with the present aspect of Cuernavaca and the _barrancas_ surrounding it.”--K.] At the bottom of the ravine was seen a little stream, which, oozing from the stony bowels of the sierra, tumbled along its narrow channel and contributed by its perpetual moisture to the exuberant fertility of the valley. This rivulet, which at certain seasons of the year was swollen to a torrent, was traversed at some distance below the town, where the sloping sides of the barranca afforded a more practicable passage, by two rude bridges, both of which had been broken, in anticipation of the coming of the Spaniards. The latter had now arrived on the brink of the chasm which intervened between them and the city. It was, as has been remarked, of no great width, and the army drawn up on its borders was directly exposed to the archery of the garrison, on whom its own fire made little impression, protected as they were by their defences. The general, annoyed by his position, sent a detachment to seek a passage lower down, by which the troops might be landed on the other side. But, although the banks of the ravine became less formidable as they descended, they found no means of crossing the river, till a path unexpectedly presented itself, on which, probably, no one before had ever been daring enough to venture.