In setting out the walls of a city the choice of a healthy situation is of the first importance: it should be on high ground, neither subject to fogs nor rains; its aspects should be neither violently hot nor intensely cold, but temperate in both respects.

Some people do indeed say that Eratosthenes could not have inferred the true measure of the earth. Whether true or untrue, it cannot affect the truth of what I have written on the fixing of the quarters from which the different winds blow.

A harmonious design requires that nothing be added or taken away.

There are also half bricks. As the bricks are always laid so as to break joints, this lends strength and a not unattractive appearance to both sides of such walls.

As regards the efficacy of the art and the theories of it, I promise and expect that in these volumes I shall undoubtedly show myself of very considerable importance not only to builders but also to all scholars.

There are two styles of walls "opus reticulatum," now used by everybody and the ancient style called "opus incertum." Of these, the reticulatum looks better, but its construction makes it likely to crack. On the other hand, in the opus incertum, the rubble lying in courses and imbricated, makes a wall which though not beautiful, is stronger.

The winter oak... is very useful in buildings but when in a moist place it takes in water to its centre... and so it rots. The Turkey oak and the beech both... take in moisture to their centre and soon decay. White and black poplar, as well as willow, linden, and the agnus castus... are of great service from their stiffness... they are a convenient material to use in carving.