In my book I propose to show, how the ocean and the other seas must, by means of the sun, make our world shine with the appearance of a moon, and to the remoter worlds it looks like a star; and this I shall prove.
Show, first that every light at a distance from the eye throws out rays which appear to increase the size of the luminous body; and from this it follows that 2 ...[Footnote 10: Here the text breaks off; lines 11 and fol. are written in the margin.].
[11]The moon is cold and moist. Water is cold and moist. Thus our seas must appear to the moon as the moon does to us.
Taken from The Notebooks of Leonardo da Vinci edited by Jean Paul Richter, 1880.