But, if less successful in exploring the heavens, the Incas must be admitted to have surpassed every other American race in their dominion over the earth. Husbandry was pursued by them on principles that may be truly called scientific. It was the basis of their political institutions. Having no foreign commerce, it was agriculture that furnished them with the means of their internal exchanges, their subsistence, and their revenues. We have seen their remarkable provisions for distributing the land in equal shares among the people, while they required every man, except the privileged orders, to assist in its cultivation. The Inca himself did not disdain to set the example. On one of the great annual festivals, he proceeded to the environs of Cuzco, attended by his Court, and, in the presence of all the people, turned up the earth with a golden plough,--or an instrument that served as such,--thus consecrating the occupation of the husbandman as one worthy to be followed by the Children of the Sun.18 The patronage of the government did not stop with this cheap display of royal condescension, but was shown in the most efficient measures for facilitating the labors of the husbandman. Much of the country along the sea-coast suffered from want of water, as little or no rain fell there, and the few streams, in their short and hurried course from the mountains, exerted only a very limited influence on the wide extent of territory. The soil, it is true, was, for the most part, sandy and sterile; but many places were capable of being reclaimed, and, indeed, needed only to be properly irrigated to be susceptible of extraordinary production. To these spots water was conveyed by means of canals and subterraneous aqueducts, executed on a noble scale. They consisted of large slabs of freestone nicely fitted together without cement, and discharged a volume of water sufficient, by means of latent ducts or sluices, to moisten the lands in the lower level, through which they passed. Some of these aqueducts were of great length. One that traversed the district of Condesuyu measured between four and five hundred miles. They were brought from some elevated lake or natural reservoir in the heart of the mountains, and were fed at intervals by other basins which lay in their route along the slopes of the sierra. In this descent, a passage was sometimes to be opened through rocks,--and this without the aid of iron tools; impracticable mountains were to be turned; rivers and marshes to be crossed; in short, the same obstacles were to be encountered as in the construction of their mighty roads. But the Peruvians seemed to take pleasure in wrestling with the difficulties of nature. Near Caxamarca, a tunnel is still visible, which they excavated in the mountains, to give an outlet to the waters of a lake, when these rose to a height in the rainy season that threatened the country with inundation.19