arm of the law, and quite as liable to break out in unexpected times and places as were the long-slumbering fires of their own volcanoes. Again and again in Spanish colonial history was the cruel Indian warfare of our own times enacted. During a time of famine they burned the palace of the viceroy over his head and tore down some of the public buildings in a blind fury which struck alike at friend and at foe. Even the labors of their kind-hearted spiritual Fathers were several times repaid by general murder and pillage.
Famines were sadly common. At one time this disaster was followed by a plague which carried off two million people. In the all-absorbing search for gold the old system of irrigation was neglected, and the mountains, made bare of their natural covering of trees, ceased to regulate the supply of moisture. The streams, suddenly swollen by rain, often became raging torrents, and, overleaping their natural bounds, poured down the mountain-sides into the lakes. In the Valley of Mexico there were five of these which were often so full in times of freshets that they overflowed every barrier and ran together.
Lake Tezcuco, in which the City of Mexico originally stood, and which is still near it, is twenty-six feet lower than Lake Zumpango, farther north. In 1607, after the city had been several times flooded by the influx of the waters from the upper lake, it was resolved that it should be drained by tunneling the mountain-wall which surrounds the valley at its lowest point. Fifteen thousand Indians were set to work on this gigantic enterprise, and by a reckless sacrifice of human life the subterranean canal, twelve miles long, was cut through in a few months, making an outlet to the sea. But the torrents
