M. Vitruvius per Iocundum solito castigatior factus cum figuris et tabula ut iam legi et intelligi possit

Natural decor will also exist if light is captured for bedrooms and libraries from the east; for baths and winter quarters, from the winter west; for picture galleries and where constant light is needed, from the north: which region of the sky is neither brightened nor obscured by the course of the sun, but is certain and immutable throughout the day. Distribution is the convenient dispensation of resources and place, and the sparing and reasoned tempering of expenses in works. This will be observed if, first, the architect does not seek those things which cannot be found or prepared except at great cost. For in all places there is not a supply of pit-sand, nor of stone rubble, nor of fir, nor of pine, nor of marble: but one thing grows in one place, another in another, the transportation of which is difficult and expensive. Where there is no pit-sand, one must use river or washed sea sand. Shortages of fir or pine shall also be avoided by using cypress, poplar, elm, or cedar. The rest shall also be explained similarly to these. The second degree of distribution will be when buildings are disposed according to the use of the heads of households, or the wealth of money, or the dignity of elegance. For it seems that urban houses ought to be constituted one way, and those to which fruits flow from rural possessions another; not the same for usurers, nor for the wealthy and delicate; but for the powerful, by whose thoughts the republic is governed, they will be arranged according to use: and generally, distributions of buildings must be made that are suitable for all persons.

Concerning the parts of architecture in the distributions of private and public buildings, and of gnomonics and mechanics. Chapter III.

The parts of architecture itself are three: building, gnomonics, and mechanics. Building is divided into two parts, of which one is the placement of walls and common works in public places, the other is the explanation of private buildings. Public distributions are three, of which one is for defense, another for religion, and the third for convenience. Defense is the theory of walls, towers, and gates, devised for the perpetual repelling of enemy attacks. Religion is the placement of the shrines of the immortal gods and sacred temples. Convenience is the disposition of all places for public use: such as ports, forums, colonnades, baths, theaters, promenades, and other things which are designed in public places by the same principles. These must be done so that a ratio of firmness, utility, and beauty is held. Firmness will be considered when there is a sinking of foundations to solid ground, and a diligent selection of resources from every material without greed. Utility, however, is the corrected and unobstructed disposition of the use of places, and a distribution suitable and convenient to the regions of each kind. Beauty, indeed, is when the appearance of the work is pleasing and elegant, and the commensuration of the members has just ratios of symmetry.