Wind is a floating wave of air, whose undulation continually varies.

All machinery is derived from nature, and is founded on the teaching and instruction of the revolution of the firmament.

I am moreover inclined to be concise when I reflect on the constant occupation of the citizens in public and private affairs, so that in their few leisure moments they may read and understand as much as possible.

Dinocrates did not leave the king, but followed him into Egypt. There Alexander, observing a harbor rendered safe by nature, an excellent center for trade, cornfields throughout all Egypt, and the great usefulness of the mighty river Nile, ordered him to build the city of Alexandria, named after the king. This was how Dinocrates, recommended only by his good looks and dignified carriage, came to be so famous.

The design of a temple depends on symmetry, the principles of which must be most carefully observed by the architect.

The 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...

For not all things are practicable on identical principles