People were to be seen eagerly embarking victuals on various kinds of hastily made barks. But little of the waves were visible in those places where the dark clouds and rain were reflected.
But where the flashes caused by the bolts of heaven were reflected, there were seen as many bright spots, caused by the image of the flashes, as there were waves to reflect them to the eye of the spectator.
The number of the images produced by the flash of lightning on the waves of the water were multiplied in proportion to the distance of the spectator's eye.
So also the number of the images was diminished in proportion as they were nearer the eye which saw them [Footnote 22. 23: Com'e provato. See Vol. II, Nos. 874-878 and 892-901], as it has been proved in the definition of the luminosity of the moon, and of our marine horizon when the sun's rays are reflected in it and the eye which receives the reflection is remote from the sea.
VI.
THE ARTIST'S MATERIALS.
Of chalk and paper (612—617).
612.
To make points [crayons] for colouring dry. Temper with a little wax and do not dry it; which wax you must dissolve with water: so that when the white lead is thus tempered, the water being distilled, may go off in vapour and the wax may remain; you will thus make good crayons; but you must know that the colours must be ground with a hot stone.
613.