Here, again, they found fresh cause for admiration in the grandeur of the city and the superior style of its architecture. The dwellings of the poorer class were, indeed, chiefly of reeds and mud. But the great avenue through which they were now marching was lined with the houses of the nobles, who were encouraged by the emperor to make the capital their residence. They were built of a red porous stone drawn from quarries in the neighborhood, and, though they rarely rose to a second story, often covered a large space of ground. The flat roofs, _azoteas_, were protected by stone parapets, so that every house was a fortress. Sometimes these roofs resembled parterres of flowers, so thickly were they covered with them, but more frequently these were cultivated in broad terraced gardens, laid out between the edifices.[277] Occasionally a great square or market-place intervened, surrounded by its porticoes of stone and stucco; or a pyramidal temple reared its colossal bulk, crowned with its tapering sanctuaries, and altars blazing with inextinguishable fires. The great street facing the southern causeway, unlike most others in the place, was wide, and extended some miles in nearly a straight line, as before noticed, through the centre of the city. A spectator standing at one end of it, as his eye ranged along the deep vista of temples, terraces, and gardens, might clearly discern the other, with the blue mountains in the distance, which, in the transparent atmosphere of the table-land, seemed almost in contact with the buildings. But what most impressed the Spaniards was the throngs of people who swarmed through the streets and on the canals, filling every door-way and window and clustering on the roofs of the buildings. “I well remember the spectacle,” exclaims Bernal Diaz: “it seems now, after so many years, as present to my mind as if it were but yesterday.”[278] But what must have been the sensation of the Aztecs themselves, as they looked on the portentous pageant! as they heard, now for the first time, the well-cemented pavement ring under the iron tramp of the horses,--the strange animals which fear had clothed in such supernatural terrors; as they gazed on the children of the East, revealing their celestial origin in their fair complexions; saw the bright falchions and bonnets of steel, a metal to them unknown, glancing like meteors in the sun, while sounds of unearthly music--at least, such as their rude instruments had never wakened--floated in the air! But every other emotion was lost in that of deadly hatred, when they beheld their detested enemy the Tlascalan stalking, in defiance, as it were, through their streets, and staring around with looks of ferocity and wonder, like some wild animal of the forest who had strayed by chance from his native fastnesses into the haunts of civilization.[279]