need the evening light, and also because the setting sun, facing them in all its splendour but with abated heat, lends a gentler warmth to that quarter in the evening. Bedrooms and libraries ought to have an eastern exposure, because their purposes require the morning light, and also because books in such libraries will not decay. In libraries with southern exposures the books are ruined by worms and dampness, because damp winds come up, which breed and nourish the worms, and destroy the books with mould, by spreading their damp breath over them.
2. Dining rooms for Spring and Autumn to the east; for when the windows face that quarter, the sun, as he goes on his career from over against them to the west, leaves such rooms at the proper temperature at the time when it is customary to use them. Summer dining rooms to the north, because that quarter is not, like the others, burning with heat during the solstice, for the reason that it is unexposed to the sun's course, and hence it always keeps cool, and makes the use of the rooms both healthy and agreeable. Similarly with picture galleries, embroiderers' work rooms, and painters' studios, in order that the fixed light may permit the colours used in their work to last with qualities unchanged.
CHAPTER V
HOW THE ROOMS SHOULD BE SUITED TO THE STATION OF THE OWNER
1. After settling the positions of the rooms with regard to the quarters of the sky, we must next consider the principles on which should be constructed those apartments in private houses which are meant for the householders themselves, and those which are to be shared in common with outsiders. The private rooms are those into which nobody has the right to enter without an invitation, such as bedrooms, dining rooms, bathrooms, and all others used for the like purposes. The common are those which any of the people have a perfect right to enter, even without an invita-
