Most of these beneficent works of the Incas were suffered to go to decay by their Spanish conquerors. In some spots, the waters are still left to flow in their silent, subterraneous channels, whose windings and whose sources have been alike unexplored. Others, though partially dilapidated, and closed up with rubbish and the rank vegetation of the soil, still betray their course by occasional patches of fertility. Such are the remains in the valley of Nasca, a fruitful spot that lies between long tracts of desert; where the ancient water-courses of the Incas, measuring four or five feet in depth by three in width, and formed of large blocks of uncemented masonry, are conducted from an unknown distance. The greatest care was taken that every occupant of the land through which these streams passed should enjoy the benefit of them. The quantity of water allotted to each was prescribed by law; and royal overseers superintended the distribution, and saw that it was faithfully applied to the irrigation of the ground. *20 [Footnote 20: Pedro Pizarro, Descub. y Conq., Ms. - Memoirs of Gen-Miller, vol II p. 220.] The Peruvians showed a similar spirit of enterprise in their schemes for introducing cultivation into the mountainous parts of their domain. Many of the hills, though covered with a strong soil, were too precipitous to be tilled. These they cut into terraces, faced with rough stone, diminishing in regular gradation towards the summit; so that, while the lower strip, or anden, as it was called by the Spaniards, that belted round the base of the mountain, might comprehend hundreds of acres, the uppermost was only large enough to accommodate a few rows of Indian corn. *21 Some of the eminences presented such a mass of solid rock, that, after being hewn into terraces, they were obliged to be covered deep with earth, before they could serve the purpose of the husbandman. With such patient toil did the Peruvians combat the formidable obstacles presented by the face of their country! Without the use of the tools or the machinery familiar to the European, each individual could have done little; but acting in large masses, and under a common direction, they were enabled by indefatigable perseverance to achieve results, to have attempted which might have filled even the European with dismay. *22 [Footnote 21: Miller supposes that it was from these andenes that the Spaniards gave the name of Andes to the South American Cordilleras. (Memoirs of Gen. Miller, vol II. p. 219.) But the name is older than the Conquest, according to Garcilasso, who traces it to Anti, the name of a province that lay east of Cuzco. (Com. Real., Parte 1, lib. 2, cap. 11.) Anta, the word for copper, which was found abundant in certain quarters of the country, may have suggested the name of the province, if not immediately that of the mountains.] [Footnote 22: Memoirs of Gen. Miller, ubi supra. - Garcilasso, Com. Real. Parte 1, lib. 5, cap. 1.]