According to the plan of operations settled by Cortés, Sandoval, with his division, was to take a southern direction, while Alvarado and Olid would make the northern circuit of the lakes. These two cavaliers, after getting possession of Tacuba, were to advance to Chapoltepec and demolish the great aqueduct there, which supplied Mexico with water. On the tenth of May they commenced their march; but at Acolman, where they halted for the night, a dispute arose between the soldiers of the two divisions, respecting their quarters. From words they came to blows, and a defiance was even exchanged between the leaders, who entered into the angry feelings of their followers.[414] Intelligence of this was soon communicated to Cortés, who sent at once to the fiery chiefs, imploring them, by their regard for him and the common cause, to lay aside their differences, which must end in their own ruin and that of the expedition. His remonstrance prevailed, at least, so far as to establish a show of reconciliation between the parties. But Olid was not a man to forget, or easily to forgive; and Alvarado, though frank and liberal, had an impatient temper much more easily excited than appeased. They were never afterwards friends.[415] The Spaniards met with no opposition on their march. The principal towns were all abandoned by the inhabitants, who had gone to strengthen the garrison of Mexico, or taken refuge with their families among the mountains. Tacuba was in like manner deserted, and the troops once more established themselves in their old quarters in the lordly city of the Tepanecs.[416] Their first undertaking was to cut off the pipes that conducted the water from the royal streams of Chapoltepec to feed the numerous tanks and fountains which sparkled in the court-yards of the capital. The aqueduct, partly constructed of brickwork and partly of stone and mortar, was raised on a strong though narrow dike, which transported it across an arm of the lake; and the whole work was one of the most pleasing monuments of Mexican civilization. The Indians, well aware of its importance, had stationed a large body of troops for its protection. A battle followed, in which both sides suffered considerably, but the Spaniards were victorious. A part of the aqueduct was demolished, and during the siege no water found its way again to the capital through this channel.