In this manner we gained some ground every day, which we secured by parapets and other defences, and preserved during the night.  Every evening at sunset, the company which was first for duty, was entrusted with the advanced post, to which they sent forty men; the second company sent an equal number at midnight, and the relieved guard did not quit their post, but had to remain sleeping on the ground; the third company did the same the same two hours before day-break, and the second now lay down to sleep, so that we now had 120 men on guard.  Sometimes our whole detachment had to remain under arms the whole night, especially on the following occasion:  We learnt from some of our prisoners, that the Mexicans intended to force our post by a great effort, which would have frustrated the other two attacks.  For this purpose, all the warriors of nine towns around the lake, including those of Tacuba, Izcapuzalco, and Tenajocan, were by a joint attack upon our rear to carry off our baggage and destroy our bakery in Tacuba, while the Mexicans were to assail us in front on the causeway.  We immediately communicated this intelligence to our cavalry and allies at headquarters, warning them to keep on the alert.  In pursuance of this plan, we were attacked both in front and rear for several successive nights, from midnight to day-break.  Sometimes the enemy came on with a prodigious noise of shouting and military instruments, and at other times stole upon us in profound silence; but their night attacks were never made with so much resolution as those during the day.  Yet we were harassed to death with continual watching, fatigue, and wounds, and constantly exposed to cold winds and almost incessant rain.  Our post was reduced to a mere splash of mud and water, and our only food was maize and miserable herbs.  When we complained, the only comfort given us by our officers, was that such is the fortune of war.  Yet all our efforts, fatigues, and privations, were of little avail; as the parapets we destroyed and the ditches we filled up during the day, were uniformly replaced next night by the enemy.

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