In the midst of all this great variety of subjects, an individual cannot attain to perfection in each, because it is scarcely in his power to take in and comprehend the general theories of them.

Philosophy treats of physics where a more careful knowledge is required because the problems which come under this head are numerous... So the reader of Ctesibius or Archimedes and the other writers of treatises of the same class will not be able to appreciate them unless he has been trained in these subjects by the philosophers.

Heat is a universal solvent, melting out of things their power of resistance, and sucking away and removing their natural strength with its fiery exhalations so that they grow soft, and hence weak, under its glow.

Thus by such victory, not by machines but in oppositions to the principle to the principles of machines, has the freedom of states been preserved by the cunning of architects.

There 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.

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.

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