Sacred Texts  Age of Reason  Index 
XV. Astronomy Index
  Previous  Next 
Buy this Book at Amazon.com

The Da Vinci Notebooks at sacred-texts.com

908.

OF HALOS ROUND THE MOON.

On the moon's halo.I have found, that the circles which at night seem to surround the moon, of various sizes, and degrees of density are caused by various gradations in the densities of the vapours which exist at different altitudes between the moon and our eyes. And of these halos the largest and least red is caused by the lowest of these vapours; the second, smaller one, is higher up, and looks redder because it is

p. 168

seen through two vapours. And so on, as they are higher they will appear smaller and redder, because, between the eye and them, there is thicker vapour. Whence it is proved that where they are seen to be reddest, the vapours are most dense.


Next: 909.