The destruction of the aqueduct of Chapoltepec, from which so much had been expected, by cutting off the water which supplied the city of Mexico, was unavailing, neither could we starve them into a surrender, as they were regularly supplied with every thing they wanted by means of their canoes from the towns around the lake. In order to prevent this, two of our brigantines were ordered to cruize every night on the lake, to intercept these supplies. This measure answered the purpose in some degree, but not effectually, as some of the canoes escaped into the city every night. At this time the Mexicans laid a plan to surprise our two cruizing brigantines. Having concealed thirty of their largest piraguas among some tall reeds on the borders of the lake, they sent several canoes, as if carrying provisions, to decoy our vessels into the snare, and even fixed a number of large wooden piles under water at the place to which our vessels were to be inveigled. On the appearance of the decoy-canoes, our two vessels made immediately towards them, the canoes rowing away towards the ambush followed by our brigantines. As soon as they arrived at the place, the thirty piraguas immediately surrounded them, and wounded every officer, soldier, and mariner on board, by their first flight of arrows. Our vessels could not move on account of the piles, and the enemy continued the assault with the utmost vigour. One of the captains, named Portilla, was slain, and Captain Pedro Barba, the commander of our crossbows, died of his wounds. This ambush completely succeeded, as the two brigantines fell into the hands of the enemy. They belonged to the principal division of our flotilla, which was commanded by Cortes in person, who was much exasperated by the loss; but he soon repayed the enemy in their own way. He constantly sent out some vessels every night to scour the lake, and on one occasion they brought in some prisoners of consequence, from whom he learnt that the enemy had formed another ambuscade of forty large piraguas and as many canoes. He now laid a plan to turn their schemes against themselves; for which purpose he sent six vessels one night with muffled oars, to conceal themselves in a water-cut at the edge of the lake, covered with bushes and tall reeds, about a quarter of a league from the ambushment of the enemy. A single brigantine was then sent out early in the morning, as if in search of the canoes which carried provisions to Mexico, and having the prisoners on board to point out the place where the enemies fleet lay concealed. The enemy sent as before some loaded canoes to decoy the brigantine towards the ambush, and our vessel pursued them until near the place, where it lay-to, as if fearful to approach. The Mexican fleet now sallied out upon them, and our brigantine rowed away towards the place where the six others were concealed, closely followed up by the enemy. When arrived near enough, the brigantine fired two shots as a signal, on which the other vessels pushed out against the enemy, running down many of their vessels, dispersing all the rest, and making a great number of prisoners. This sickened them at ambushments, and from henceforwards they did not attempt to cross the lake in their canoes so openly.

Our three divisions of the land army continued to pursue their plan for gradually advancing along the causeways. Always as we gained ground, we pulled down the houses on each side, filling up the ditches or canals which intersected the causeways, and strengthening our posts; in which, and in all the operations of the war, we were excellently seconded by our brave Tlascalan allies. On our attack, the Mexicans broke down one of the bridges in the rear of their own barricades and parapets, leaving one narrow passage at a place where the water was very deep as a decoy, and even dug trenches and pitfalls where the water was more shallow, placing pallisades in the deep water to prevent the approach of our vessels, and constructing parapets on both sides of the breach. They had also a number of canoes in readiness to sally out upon us on a concerted signal. When all these preparations were in readiness, they made a combined attack upon us in three several directions. One body advanced towards our rear from the side of Tacuba, a second directly on our front along the causeway from the city, and the third by the ruins of the houses which we had destroyed. We repulsed the enemy on all sides; and one party of us, having forced them from the works at the broken bridge, crossed the water up to our necks at the place they had left open for us, and rashly pushed on to an open place where there were some large temples and towers. We were here assailed on all sides by fresh troops from the houses and terraces, and those whom we pursued faced about and fought us in front. We now found it necessary to retreat, which we did with the utmost order till we came to the pass at the broken bridge, which was occupied by the enemy in canoes; and as the others pressed upon our rear, we were forced to throw ourselves into the lake and to get over any way we could. Those who could not swim got entangled among the concealed ditches and pits in the shallow water, where the enemy closed in upon us, wounding the whole party, and even taking five of our soldiers alive. The vessels which came to our relief were unable to approach, on account of the pallisades, and they lost two of their soldiers on this occasion. It was wonderful we were not all destroyed at this dangerous pass. At one time I was laid hold of by a number of the enemy; but God gave me strength to disengage my arm, and with the assistance of my good sword, I extricated myself from their grasp. Though wounded, I escaped to the dry ground, where I fainted and remained for some time insensible, owing to my great exertions and the loss of blood. When the enemy had me in their clutches, I recommended myself to the aid of God and his blessed Mother, and they heard my prayer: Glory be to them for all their mercies! From the time that we had cleared the flanks of our post by the destruction of the houses, Alvarado had brought a part of his cavalry thither; and one of them, who had crossed along with us at the broken bridge, lost both his horse and his own life. Fortunately all the rest were then with Alvarado in Tacuba; for if they had been with us they must have all been destroyed from the tops of the houses and temples, as the action took place almost within the city of Mexico. The enemy was much elated by the success of this day, and continued to assail our posts day and night. Cortes was much displeased at the defeat we had sustained, which he attributed to our having neglected his orders; which were always to fill up the cuts in the causeway as we advanced, by means of timber and rubbish.

In the space of four days, counting from our late defeat, we filled up the great aperture at the broken bridge, and established our advanced post at this place, but lost six of our soldiers in the course of this operation. The enemy established a post directly in front of us, which they secured by a ditch and parapet, so as to protect themselves from our shot. They made a large fire in front of their post, by which they were concealed from our view, except when they had occasion to renew the fire, which was sometimes extinguished by the frequent heavy rains which prevailed at this season. They kept profound silence on guard, except when interrupted by loud whistling, which they used as signals. Every morning we marched against the enemy, with whom we fought during the whole day, and retreated to our post towards evening, covered with wounds. Before retreating, we sent back our allies, whose numbers embarrassed us in the narrow causeway, and then fell back step by step, flanked by our armed brigantines, and firing on the enemy as they pressed upon us during the retreat.

About this time, the inhabitants of the cities on the lake grew weary of the long protracted warfare, and sent deputations to our general, offering to submit themselves to his authority, and declaring that they had been constrained by the Mexicans to persist hitherto in their hostilities against us. Cortes received them very graciously, and assured them of his protection, providing that they should conduct themselves properly for the future, and give him their assistance by supplying canoes and provisions to our army, and in the construction of barracks for the troops. They readily promised all this, but performed very badly. Cortes had huts built for his detachment59; but the rest of us remained exposed to the weather, which was exceedingly severe and distressing, as it rained almost incessantly during June, July, and August.