Andrews, Ernest John, 1863-, Howland, Howard Newell, 1865- joint author · New York, London, The Macmillan company · leaf 344
nt, from the law ofreflection, that the reflectedrays near the outer edge ofthe mirror will not pass tothe principal focus. And itwill be the same if the rays,instead of being parallel,diverge from any point in front of the mirror, — the outerrays will focus nearer the mirror. This failure of… … Fig. 206. 330 LIGHT [§§545-546 parabolic instead of spherical, and the better class ofmirrors are so made. As the surface of a comparativelysmall section of a sphere is nearly parabolic in form, theaberration is greatly reduced by using spherical mirrors ofslight curvature. 546. Discussion of…
Physics
Internet Archive · Library of Congress · Public Domain Mark 1.0. Free to use for anything.
