Page:The wonders of optics (1869).djvu/117

Rh The law may be easily illustrated by allowing a ray of light to fall upon the surface of a vessel of water, as shown in the preceding figure.

The light of the stars and planets undergoes a similar deviation when passing in its course through the earth's atmosphere; and at the moment we see the rising of the sun, the moon, or a star, they are in reality still

below the horizon. Our eyes consequently are still deceiving us, no matter what part of the domain of optics we may enter.