There is no scarcity of rain in either country, and yet both are dry and parched, while the number and size of their torrent-beds show with what violence the mountain-streams descend into lakes or rivers, rather agents of destruction than of benefit to the land.
Strangely enough, both countries have been in possession of races who understood that water was the very life-blood of the land, and worked hard to build systems of arteries to distribute it over the surface.

In both countries, the warlike Spaniards overcame these races, and irrigating works already constructed were allowed to fall to ruin.
When the Moriscos were expelled from their native provinces of Andalusia and Granada, their places were but slowly filled up with other settlers, so that a great part of their aqueducts and watercourses fell into decay within a few years.

These new colonists, moreover, came from the Northern provinces, where the Moorish system of culture was little understood; and, incredible as it may seem, though they must have had ocular evidence of the advantages of artificial irrigation, they even neglected to keep in repair the water-channels on their own ground.

Now the traveller, riding through Southern Spain, may see in desolate barren valleys remains of the Moorish works which centimes ago brought fertility to grain-fields and orchards, and made the country the garden of Europe.
There was another nation who seem to have far surpassed both Moors and Aztecs in the magnitude of their engineering-works for this purpose.
The Peruvians cut through mountains, filled up valleys, and carried whole rivers away in artificial channels to irrigate their thirsty soil.

The historians' accounts of these water-works as they were, and even travellers' descriptions of the ruins that still remain, fill us with astonishment.