When his companions wished to return to their country, and asked him what message he wished them to carry home, he bade them say this: that children … - Vitruvius

The oak... has not the efficacy of the fir, nor the cypress that of the elm.

Music, also, the architect ought to understand so that he may have knowledge of the canonical and mathematical theory, and besides be able to tune ballistae, catapultae, and scorpiones to the proper key. For to the right and left in the beams are the holes in the frames through which the strings of twisted sinew are stretched by means of windlasses and bars, and these strings must not be clamped and made fast until they give the same correct note to the ear of the skilled workman.

Towns should be laid out not as an exact square nor with salient angles, but in circular form, to give a view of the enemy from many points. Defense is difficult where there are salient angles because the angle protects the enemy rather than the inhabitants.