The wearied troops of Cortéz were in no plight to respond to the summons of the Chalcans at that moment, for their hurried foray and incessant conflicts with the enemy had made them anxious for the repose they might justly expect in Tezcoco. Nevertheless, Cortéz did not choose to rely upon his naval enterprise alone; but, conscious as he was of holding the main key of the land as well as water, he despatched, without delay, his trusty Sandoval with three hundred Spanish infantry and twenty horse to protect the town of Chalco and reduce the hostile fortifications in its vicinity. This duty he soon successfully performed. But the Aztecs renewed the assault on Chalco with a fleet of boats, and were again beaten off with the loss of a number of their nobles, who were delivered by the victors to Sandoval whom Cortéz had sent back to support the contested town as soon as the news of the fresh attack reached him. By this time the brigantines were nearly completed, and the canal dug by which they were to be carried to the waters of the lake, for, at that time, the town of Tezcoco was distant from its margin. He dared not trust these precious materials for his future success beyond the shelter of his citadel in Tezcoco, since every effort had been already made by hostile and marauding parties to destroy them; and he was therefore obliged to undergo the trouble of digging this canal, about half a league in length, in order to launch his vessels when the moment for final action arrived. Nor was his heart uncheered by fresh arrivals from the old world. Two hundred men, well provided with arms and ammunition, and with upwards of seventy horses,--coming most probably from Hispaniola,--found their way from Vera Cruz to Tezcoco, and united themselves with the corps of Cortéz. In the meantime the Emperor again directed his arms against his recreant subjects of Chalco, which he seemed resolved to subdue and hold at all hazards, so as effectually to cut off the most important land approach to his capital. Envoys arrived in the Spanish camp with reports of the danger that menaced them, and earnest appeals for efficient support. This time, Cortéz resolved to lead the party destined for this service, and, on the 5th of April, set out with thirty horsemen, three hundred infantry and a large body of Tlascalans and Tezcocans, to succor a city whose neutrality, at least, it was important, as we have already shown, should eventually be secured. He seems to have effected, by his personal influence in Chalco and its neighborhood, what his lieutenant Sandoval had been unable to do by arms, so that, he not only rendered a large number of loyal Aztecs passive, but even secured the co-operation of additional auxiliaries from among the Chalcans and the tribes that dwelt on the borders of their lake.