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.

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

It was a wise and useful provision of the ancients to transmit their thoughts to posterity by recording them in treatises, so that they should not be lost, but, being developed in succeeding generations through publications in books, should gradually attain in later times, to the highest refinement of learning.

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.

The winter oak... is very useful in buildings but when in a moist place it takes in water to its centre... and so it rots. The Turkey oak and the beech both... take in moisture to their centre and soon decay. White and black poplar, as well as willow, linden, and the agnus castus... are of great service from their stiffness... they are a convenient material to use in carving.

Some springs are acid, as at Lyncestus and in Italy in the Velian country, at Teano in Campania, and in many other places. These when used in drinks have the power of breaking up stones in the bladder, which form in the human body.

But as for me, Emperor, nature has not given me stature, age has marred my face, and my strength is impaired by ill health. Therefore, since these advantages fail me, I shall win your approval, as I hope, by the help of my knowledge and my writings.