throughout, and from three and a half to four varas in height. It is composed entirely of stone, with buttresses of solid masonry on both sides, and three sluices, by which, in any emergency, a communication between the lakes can be effected and regulated at the same time. The whole was concluded, like the gallery of Nochistongo, in eleven months, although as many years would now be required for such an undertaking. But in those days the sacrifice of life, and particularly of Indian life, in public works, was not regarded. Many thousands of the natives perished before the desague was completed; and to their loss, as well as to the hardships endured by the survivors, may be ascribed the horror with which the name of Huehuetoca is pronounced by their descendants.
"It is not our intention to follow the progress of the canal of Huehuetoca through all the various changes which occurred in the plans pursued with respect to it from 1637, when the direction of the work was again taken from Martinez and confided to the Franciscan monks, until 1767, when, under the viceroyalty of the Marques de Croix, the Consulado or corporate body of Mexican merchants, engaged to complete this great national undertaking. The necessity of converting the tunnel of Martinez into an open cut, had long been acknowledged, it having been found impossible to prevent the tunnel from being continually choked up by the sand and rubbish deposited by the water on its passage; but as the work was only prosecuted with vigor when the danger of an inundation became imminent, and was almost suspended in the dry years, two thousand three hundred and ten varas of the northern gallery remained untouched, after the expiration of one hundred and thirty years when the Consulado was intrusted with the completion of the arduous task. As the old line of the gallery was to be preserved, it became necessary to give the cut which was to be sunk, perpendicularly upon it, an enormous width at the top, in order to prevent the sides from falling in; and in the more elevated parts, between the mountains of Sincoque and the hill of Nochistongo, for the space of two thousand six hundred and twenty-four feet, the width, across, varies from two hundred and seventy-eight to six hundred and thirty feet, while the perpendicular depth is from one hundred and forty-seven to one hundred and ninety-six feet. The whole length of the cut from the sluice called the vertideros to the salto or fall of the river Tula, is sixty-seven thousand five hundred and thirty-seven feet or twenty-four thousand five hundred and thirty Mexican varas. The highest point of the hill of Nochistongo is that called Boveda Real, and it
