Bricks will be most serviceable if made two years before using; for they cannot dry thoroughly in less time. When fresh undried bricks are used in a wall, the stucco covering stiffens and hardens into a permanent mass, but the bricks settle and the motion caused by their shrinking prevents them from adhering to it, and they are separated from their union with it. At Utica in constructing walls they use brick only if it is dry and made five years previously, and approved as such by the authority of a magistrate.

There are also kinds of water that cause death, as they run through harmful juices in the soil and become poisonous.

The thickness of the walls should be sufficient for two armed men to pass each other with ease.

If then, at this great distance, our human vision can discern that sight, why, pray, are we to think that the divine splendor of the stars can be cast into darkness?

When the juices of trees have no means of escape, they clot and rot in them, making the trees hollow and good for nothing.

Remembering that Eratosthenes of Cyrene, employing mathematical theories and geometrical methods, discovered from the course of the sun, the shadows cast by an equinoctial gnomon, and the inclination of the heaven that the circumference of the earth is two hundred and fifty-two thousand stadia, that is, thirty-one million five hundred thousand paces.

Altars should face the east, and should always be placed on a lower level than are the statues in the temples, so that those who are praying and sacrificing may look upwards towards the divinity.