Geometry is of much assistance in architecture, and in particular it teaches us the use of the rule and compasses, by which especially we acquire readiness in making plans for buildings in their grounds, and rightly apply the square, the level, and the plummet. By means of optics the light in buildings can be drawn from fixed quarters of the sky. Difficult questions involving symmetry are solved by means of geometrical theories and methods.

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

At Halicarnassus, the house of that most potent king Mausolus, though decorated throughout with Proconnesian marble, has walls built of brick which are to this day of extraordinary strength, and are covered with stucco so highly polished that they seem to be as glistening as glass. That king did not use brick from poverty; for he was choke-full of revenues, being ruler of all Caria.

Of course, we need not be surprised if artistic excellence goes unrecognized on account of being unknown; but there should be the greatest indignation when, as often, good judges are flattered by the charm of social entertainments into an approbation which is a mere a pretence.

Basilicas should be constructed on a site adjoining the forum and in the warmest possible quarter, so that in winter business men may gather in them without being troubled by the weather.

Cold winds are disagreeable, hot winds enervating, moist winds unhealthy.

For siege works against bold and venturesome men should be constructed on one plan, on another against cautious men, and on still another against the cowardly.