The [engineer] should be equipped with knowledge of many branches of study and varied kinds of learning, for it is by his judgement that all work done by the other arts is put to test. This knowledge is the child of practice and theory.

Our ancestors, when about to build a town or an army post, sacrificed some of the cattle that were wont to feed on the site proposed and examined their livers. If the livers of the first victims were dark-coloured or abnormal, they sacrificed others, to see whether the fault was due to disease or their food. They never began to build defensive works in a place until after they had made many such trials and satisfied themselves that good water and food had made the liver sound and firm, healthfulness being their chief object.

In Sparta, paintings have been taken out of certain walls by cutting through the bricks, then have been placed in wooden frames, and so brought to the Comitium to adorn the aedileship of [C. Visellius] Varro and [C. Licinius] Murena.

Bricks should be made in Spring or Autumn so that they may dry uniformly.

Wind is a floating wave of air, whose undulation continually varies.

Since, therefore, individuals as well as the public are so indebted to these writers for the benefits they enjoy, I think them not only entitled to the honour of palms and crowns, but even to be numbered among the gods.

In all matters but particularly in architecture, that which is signified is the subject of which we may be speaking and that which gives significance is a demonstration on scientific principles. One who professes himself an architect should be well versed in both directions.