On the sun mirrored upon the water.

t, m S f h, c, a n r / If the sun is seen from all the seas that have daylight, all those seas are seen by the sun. Therefore all the luminous water becomes a mirror of the sun — the whole reflected in all that water by likeness, and the whole appearing to the eye in each part. I ask then: for what reason, when the ship travels and one sees the sun, does the eye not see the whole sea luminous, and why does a single sun always seem to travel along the course of the boat? / Definition. / The sun makes as many pyramids as there are holes and apertures through which its rays can penetrate, and as many as there are eyes of the animals that behold it. Therefore, the sun always being the base of each pyramid, the sun mirrored in the water appears to the eye to be as far beneath that water as it is above it; and that mirrored sun becomes the base of the pyramid that ends in the eye, and the mirrored sun will appear as large as the section of the pyramid cut by the surface of the water at a n. Let t r be the water, m the sun, f the sun mirrored in the water, S h c be the pyramid of the mirrored sun, and a n be the aforesaid section of the pyramid.