Quaestiones Naturales

Is not that the cause which Theophrastus assigns,—that heat (to wit) shuns the cold, and is constrained by it on every side? Hence the waters are hottest in the bottom of the sea. And so it is on land; for springs are hotter in winter, and then lakes and rivers send up most vapors, because the heat is compelled to the bottom by the prevailing cold. Or it may be, nets do not rot at that time more than at another; but being frozen and dried in the cold, since they are therefore the more easily broken by the waves, they are liable to something like putrefaction

and rottenness. And they suffer most in the cold (as strained cords are aptest to break in such a season), because then there be most frequent storms at sea. Therefore fishermen guard their nets with certain tinctures, for fear they should break. Otherwise a net, neither tinged nor daubed with any thing, might more easily deceive the fish; since line is of an air color, and is not easily discerned in the sea.