The most remarkable results of the rule of the Incas are seen in the material well-being which they secured to their people. All the historians speak of the really extraordinary perfection to which Peruvian agriculture had been carried, though the use of iron was quite unknown. The solar religion fits perfectly with the habits of an agricultural people, and the Incas thought it became them, as children of the Sun, to encourage the cultivation of the soil. They ordered the execution of great public works, such as supporting walls to prevent the sloping ground from being washed away; irrigation canals, some of which measured five hundred miles, and which were preserved with scrupulous care; magazines of guano, the fertilizing virtues of which were known in Peru long before they were learned in Europe.[57] The Spaniards are far from having maintained Peruvian agriculture at the level it had reached under the Incas. Splendid roads stretched from Cuzco towards the four quarters of heaven; and Humboldt still traced some of them, paved with black porphyry, or in other cases cemented or rather macadamized, and often launched over ravines and pierced through hills with remarkable boldness.[58] The Incas had established reservoirs of drinking water for the public use from place to place along these roads, and likewise pavilions for their own accommodation when they were traversing their realms, on which occasions they never travelled more than three or four leagues a day. Bridges were thrown across the rivers, sometimes built of stone, but more often constructed on the method, so frequently described, that consists in uniting the opposing banks by two parallel ropes, along which a great basket is slung.[59] A system of royal courier posts measured the great roads as in Mexico. There were many important cities in Peru, and, according to a contemporary estimate cited by Prescott, the capital, Cuzco, even without including its suburbs, must have embraced at least two hundred thousand inhabitants.[60] Architecture was in a developed stage. We shall have to speak of the temples presently. The Inca's palaces--and there was at least one in every city of any importance--were of imposing dimensions, and a high degree of comfort and luxury was displayed within them. Gold glittered on the walls and beneath the roofs which were generally thatched with straw. They were provided with inner courts, spacious halls, sculptures in abundance, but inferior, it would seem, to those of Central America, and baths in which hot or cold water could be turned on at will.[61] In a word, when we remember from how many resources the Peruvians were still cut off by their ignorance and isolation, we cannot but admit that a genuine civilization is opening before our eyes, the defects of which must not blind us to its splendour. And since this civilization was in great part due (we shall see the force of the qualification presently) to the continuous efforts of the Incas, our