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

Oak... lasts for an unlimited period when buried in underground structures... when exposed to moisture... it cannot take in liquid on account of its compactness, but, withdrawing from the moisture, it resists it and warps, thus making cracks.

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.

Architect's designs must refer to the unquestionable perfection of the body's symmetry and proportions. If a building is to create a sense of eurythmia, it is essential that it mirrors these natural laws of harmony and beauty

From the exterior face of the wall towers must be projected, from which an approaching enemy may be annoyed by weapons, from the embrasures of those towers, right and left.

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.