[AS. leoht, liht.] The agent which produces vision and thereby enables us to see objects. Light comes to us from self-luminous bodies in the heavens - such as the sun, the fixed stars, nebulae, and some meteors; and from substances on the earth - such as the electric light, burning gas and oil, etc. Light proceeds from all luminous bodies in straight lines, each one of which is called a ray of light. It is supposed to consist of undulations or waves in a rare substance called the luminiferous ether. It moves at the rate of over 186,000 miles per second, or more than a million times faster than sound, and it takes eight minutes for the light of the sun to reach the earth. When light falls upon the surface of a body, part of it is reflected, the rest enters the body. Thus, when we look at a house, the light goes first from the sun to the house, and then glances from it into our eyes, and thus we are able to see a thing which does not make any light itself. When a slanting ray of light passes from air into water, glass, or anything through which it can shine, the ray in the water, glass, etc., though still a straight line, is not a continuation of its old path, but is bent as it passes from one medium to the other. This bending of the ray is called refraction. (See Prism?) Light/er. A large, open, flat-bottomed boat used in loading and unloading ships.