Then again, in the human body the central point is naturally the navel. For if a man be placed flat on his back, with his hands and feet extended, an… - Vitruvius

In walls of masonry the first question must be with regard to the sand, in order that it may be fit to mix into mortar and have no dirt in it. The kinds of pitsand are these: black, gray, red, and carbuncular. Of these the best will be found to be that which crackles when rubbed in the hand, while that which has much dirt in it will not be sharp enough. Again: throw some sand upon a white garment and then shake it out; if the garment is not soiled and no dirt adheres to it, the sand is suitable.

Some have held that there are only four winds: Solanus from the east; Auster from the south; Favonius from due west; Septentrio from the north. But more careful investigators tell us that there are eight.

These rules for symmetry were established by Hermogenes, who was also the first to devise the principal of the pseudodipteral octastyle.