CHAPTER XXIII.
472. What is the refraction of light?
When rays of light fall obliquely upon the surface of any transparent medium, they are slightly diverted from their course. This alteration of the course of the rays is called refraction, and the degree of refraction is influenced by the difference between the densities of the mediums through which light is transmitted.
"Let your light so shine before men, that they may see your good works, and glorify your father which is in heaven."—Matt. v.
473. If a ray of light falls in a straight line upon a transparent surface, is it then refracted?
In that case the ray pursues its course—there is no refraction.
474. Is the direction in which the rays are bent, or refracted, influenced by the relative densities of the media?