Reflection

(-flekshun,) or REFLEXION. [Same der iv.) (Mech.) The rebound of one body from the surface of another and impinging body.-(Phys.) The turning of a ray of light or heat from a body against which it has impinged; a reflecting is nece arily a polished surface. Light and heat, in reflections, follow the law of perfectly elastic bodies; that is, " the angle of incidence is equal to the angle of reflection." This enables us to ascertain with ease the path of a reflected ray; and to explain how it is that: 1. Plane mirrors alter the apparent position but not the size of an object: 2. Concave mirrors bring rays to a focus, and either increase or diminish the apparent size of an object, according as it is in one or other of the conjugate foci; and 3. Convex mirrors disperse rays, and diminish the apparent size of an object. [s. 759]