316 INUNDATIONS. 



Panuco, and from the northern or farther extremity 

 of the gallery an open trench, 28,216 feet long, was 

 cut to carry the water to the former river. Soon 

 after the current began to flow through this artificial 

 channel, it gradually occasioned depositions and ero- 

 sions, so that it became necessary to support the 

 roof, which was composed of marl and clay. For 

 this purpose wood was at first employed, and after- 

 ward masonry; but the arches being soon under- 

 mined, the passage at length was obstructed. 



Several plans were now proposed, and in 16 14 the 

 court of Madrid sent to Mexico a Dutch engineer, 

 Adrian Boot, who advised the construction of great 

 dikes after the Indian plan. A new viceroy, how- 

 ever, having recently arrived, who had never wit- 

 nessed the effects of an inundation, ordered Marti- 

 nez to stop up the subterraneous passage, and make 

 the water of the upper lakes return to the bed of the 

 Tezcuco, that he might see if the danger were really 

 so great as it had been represented. Being con- 

 vinced that it was so, he ordered the German to re- 

 commence his operations in the gallery. The engi- 

 neer accordingly proceeded to clear it, and contin- 

 ued working until the 20th June, 1629, when finding 

 the mass of water too great to be received by this 

 narrow outlet, he closed it in order to prevent its 

 destruction. ]n the morning the city of Mexico 

 was flooded to the depth of three feet, and, con- 

 trary to expectation, remained in that state for five 

 years. In -this interval various plans were proposed 

 for draining the neighbouring lake, although none 

 of them was carried into effect ; but the inundation 

 at length subsided in consequence of a succession 

 of earthquakes. 



Martinez, who had been imprisoned from a belief 

 that he had closed the gallery for the purpose of 

 affording the incredulous a proof of the utility of 

 his work, was now set at liberty, and constructed 

 the dike of San Christobal. He was ordered to en- 



