ocr: "Some have believed that the moon has in part d light of its own in addition to that which is given it' by the sun, and that this light is due to the cause already mentioned-namely, that our seas are illuminated by the sun. - E Leonardo means here that the dim glow ofthe rest of the moon during its crescent phase IS due to light - reflected from the earth's oceans back to - the moon's darkened portion. He adds that this light tis difficult to see because light and darkness appear more extreme when they are juxtaposed. His concept of bright contrast
