913.

The Da Vinci Notebooks at sacred-texts.com

913.

Why the planets appear larger in the East than they do overhead, whereas the contrary should be the case, as they are 3500 miles nearer to us when in mid sky than when on the horizon.

All the degrees of the elements, through which the images of the celestial bodies pass to reach the eye, are equal curves and the angles by which the central line of those images passes through them, are unequal angles  ⁴⁸⁹ ; and the distance is greater, as is shown by the excess of a b beyond a d; and the enlargement of these celestial bodies on the horizon is shown by the 9th of the 7th.

Footnotes

170:489 13: inequali, here and elsewhere does not mean unequal in the sense of not being equal to each other, but angles which are not right angles.