Chapter 2 That The City Should Have Wholesome Air
CHAPTER 2
THAT THE CITY SHOULD HAVE WHOLESOME AIR
[128] After deciding on the locality of the kingdom, the king must select a site suitable for building a city.
[129] Now the first requisite would seem to be wholesome air, for civil life presupposes natural life, whose health in turn depends on the wholesomeness of the air. According to Vitruvius [De Architectura I, 4], the most healthful spot is “a high place, troubled neither by mists nor frosts and facing neither the sultry nor the chilly parts of the sky. Also, it should not lie near marsh country.” The altitude of the place contributes to the wholesomeness of the atmosphere because highlands are open to all the breezes which purify the air; besides, the vapours, which the strength of the sun’s rays causes to rise from the earth and waters, are more dense in valleys and in low-lying places than in highlands, whence it is that the air on mountains is rarer. Now this rarified air, which is the best for easy and natural breathing, is vitiated by mists and frosts which are frequent in very damp places; as a consequence, such places are found to be inimical to health. Since marshy districts have an excess of humidity, the place chosen for the building of a city must be far from any marshes. “For when the morning breezes come at sunrise to such a place, and the mists that rise from the swamps join them, they will scatter through the town the breath of the poisonous beasts of the marshes mingled with the mist, and will render the site pestilential.” “Should, however, the walls be built in marshes that lie along the coast and face the north (or thereabouts) and if these marshes be higher than the seashore, they would seem to be quite reasonably built, since, by digging ditches, a way will be opened to drain the water of the marshes into the sea, and when storms swell the sea it will flow back into the marshes and thus prevent the propagation of the animals there. And if any animals come down from higher places, the unwonted saltiness of the water will destroy them.”
[130] Further provision for the proper proportion of heat and cold must be made when laying out the city by having it face the correct part of the sky. “If the walls, particularly of a town built on the coast, face the south, it will not be healthy,” since such a locality will be cold in the morning, for the rays of the sun do not reach it, but at noon will be baked in the full glare of the sun. As to places that face the west, at sunrise they are cool or even cold, at noon quite warm, and in the evening unpleasantly hot, both on account of the long-continued heat and the, exposure to the sun. On the other hand, if it has an eastern exposure, in the morning, with the sun directly opposite, it will be moderately warm, at noon it will not, be much warmer since the sun does not reach it, directly, but in the evening it will be cold as the rays of the sun will be entirely on the other side. And there will be the same or a similar proportion of heat and cold if the town faces the north. By experience we may learn that the change from cold to heat is unhealthy. “Animals which are transferred from cold to warm regions cannot endure but are dissolved,” “since the heat sucks up their moisture and weakens their natural strength;” whence even in salubrious districts “all bodies become weak from the heat.”
[131] Again, since suitable food is very helpful for preserving health, we must further judge of the salubrity of a place which has been chosen as a town-site by the condition of the food which grows upon its soil. The ancients were wont to explore this condition by examining the animals raised on the spot. For man, like other animals, finds nourishment in the products of the earth. Hence, if in a given place we kill some animals and find their entrails to be sound, the conclusion will be justified that man also will get good food in the same place. If, however, the members of these animals should be found diseased, we may reasonably infer that that country is no healthy place for men either.
[132] Just as a temperate climate must be sought, so good water must be made the object of investigation. For the body depends for its health on those things which men more frequently put to their use. With regard to the air it is clear that, breathing it continuously, we draw it down into our very vitals; as a result, purity of air is what conduces most to the preservation of men. But of all things put to use as nourishment, water is used most frequently both as drink and food. Nothing therefore, except good air, so much helps to make a district healthy as does pure water.
[133] There is still another means of judging the healthfulness of a place, i.e., by the ruddy complexion of the inhabitants, their sturdy, well-shaped limbs, the presence of many and vivacious children, and of many old people. On the other hand, there can be no doubt about the deadliness of a climate where people are misshapen and weak, their limbs either withering or swollen beyond proportion, where children are few and sickly, and old people rather scarce.