"Now, it is evident that an unusual flood of water could raise Tezcoco so that it would flood the city, and this is what has happened on five different occasions—in 1553, 1580, 1604, 1607, and 1629. The last inundation continued for five years, and caused an immense amount of suffering and loss. The city was covered to a depth of three feet, and the waters were finally carried off by an earthquake, which allowed them to run away through the crevices that it formed.
"Here's where we come to the history of the great cut of Nochistongo. The Spanish Government consulted all the celebrated engineers of the day, and they presented numerous plans for draining the city and keeping it out of danger from inundations. Enrico Martinez presented the plan which was adopted. It was to drain Lake Zumpango so that its waters would not be poured into Tezcoco, but would run to the Gulf of Mexico by way of Tula. For this purpose he proposed to make a tunnel through Nochistongo, to carry off the superfluous water of Zumpango, or, rather, of the river Cuatitlan, which flows into it.
YOUNG GIRLS OF TULA.
"The tunnel was commenced in November, 1607, but when completed it was found insufficient to drain the lake, and a new plan was needed. A Dutch engineer was then brought in, and he naturally proposed a system of dikes, similar to those of his own country and the dikes already built by the Aztecs. He was allowed to carry out his scheme until the arrival of a new viceroy in 1628. The new viceroy would not believe the accounts which he heard of the floods that had occurred, and he ordered Martinez to stop up the tunnel and allow the waters to take their original course. He was soon convinced of his error, and ordered the tunnel to be reopened. It was reopened and continued in use until the following June, when Martinez found that it was being destroyed by the pressure of the water, and he therefore closed it to save it from ruin. A disastrous flood followed, and this was the one that lasted five years."
"How did the people get around in that time?" Fred asked.
"They were forced to use boats," was the reply; "but the getting about was the least part of the trouble caused by the flood. Most of the houses were of adobe, and these soon crumbled and fell. The loss was so great that the Spanish Government ordered the site of the city to be changed to higher ground, but on representations by the City Council of the value of the permanent structures which would thus be rendered useless, the order was countermanded. The city was restored after the subsidence of the waters. It has been threatened several times since, but though it has been in great danger the cut and the dikes have saved it."
"But how about the making of the tunnel into a cut?"
"They put Martinez in prison as soon as the flood came, and he was kept there for several years. Then it was determined to change the tunnel into a cut, and he was released and put in charge of the work. It took 150 years to make it, and though nominally finished in 1789, it has never been entirely completed. Thousands of Indians died during the work of digging this enormous ditch. It was the greatest earthwork of its time, and in fact the greatest down to the cutting of the Suez and Panama canals. Here are the figures: