This success greatly emboldened the Mexicans, and in locust legions they pressed upon the Spanish quarters, rending the air with their unearthly shouts, and darkening the sky with their missiles. The artillery was immediately brought to bear upon them, and every volley opened immense gaps in their ranks; but the places of the dead were instantly occupied by others, and there seemed to be no end to their numbers. Never did mortal men display more bravery than these exasperated Mexicans exhibited, struggling for their homes and their rights. Twice they came very near forcing an entrance over the walls into the Spanish quarters. Had they succeeded, in a hand to hand fight numbers must have triumphed, and the Spaniards must have been inevitably destroyed; but the batteries of the Spaniards mowed down the assailants like grass before the scythe, and the Mexicans were driven from the walls. All the day long the conflict was continued, and late into the night. The ground was covered with the dead when darkness stopped the carnage. The soldiers of Narvaez, unaccustomed to such scenes, and appalled by the fury and the number of their enemies, began to murmur loudly. They had been promised the spoils of an empire which they were assured was already conquered; instead of this, they found themselves in the utmost peril, exposed to a conflict with a vigorous and exasperated enemy, surrounding them with numbers which could not be counted. Bitterly they execrated their own folly in allowing themselves to be thus deluded; but their murmurs could now be of no avail. The only hope for the Spaniards was in united and indomitable courage. The energies of Cortez increased with the difficulties which surrounded him. During the night he selected a strong force of picked men to make a vigorous sally in the morning. To nerve them to higher daring, he resolved to head the perilous enterprise himself. He availed himself of all his knowledge of Indian warfare, and of all the advantages which European military art could furnish. In the early dawn, these troops, in solid column, rushed from the gates of their fortress; but the foe, greatly augmented by the fresh troops which had been pouring in during the night, were ready to receive him. Both parties fought with ferocity which has never been surpassed. Cortez, to his inexpressible chagrin, found himself compelled to retire before the natives, who, in numbers perfectly amazing, were crowding upon him.