Leave a cavity behind the [wall] facings, and on the inside build walls two feet thick, made of red dimension stone or burnt brick or lava in courses, and then bind them to the fronts by means of iron clamps and lead. The beds and builds, all settling equally and bonded at the joints, will not let the work bulge out, nor allow the fall of the face walls which have been tightly fastened together.
Marcus Vitruvius PollioThe design of a temple depends on symmetry, the principles of which must be most carefully observed by the architect.
Marcus Vitruvius PollioFor 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.
Marcus Vitruvius PollioThere are two styles of walls "opus reticulatum," now used by everybody and the ancient style called "opus incertum." Of these, the reticulatum looks better, but its construction makes it likely to crack. On the other hand, in the opus incertum, the rubble lying in courses and imbricated, makes a wall which though not beautiful, is stronger.
Marcus Vitruvius PollioPropriety is that perfection of style which comes when a work is authoritatively constructed on approved principles. It arises from prescription, from usage, or from nature.
Marcus Vitruvius PollioThe difference between "machines" and "engines" is obviously this, that machines need more workmen and greater power to make them take effect, as for instance ballistae and the beams of presses. Engines, on the other hand, accomplish their purpose at the intelligent touch of a single workman...
Marcus Vitruvius Pollio