The boy's modern playmate : a book of sports, games, and pastimes (1890)
Wood, J. G. (John George), 1827-1889, compiler, editor, Dalziel, George, 1815-1902, engraver, Dalziel, Edward, 1817-1905, engraver · London ; New York : Frederick Warne & Co. · leaf 624
SCIENCE. 6o2 and radius of mirror i8 in., focal length =^|^=I2 in., or, if convex, = 75 Images in Mirrors. — When an object is placed before a mirror, every point of the body sends out a pencil of light, which falls upon the mirror and is reflected. The foci of all the reflected rays form the… … I. When the mirror is plane, as in Fig. 7, by the laws of reflection already stated, a is the focus of all the rays coming from A. Similarly, b is the focus of all the rays from B. Rays from all the points between A and B have their foci between a and b. Thus a complete image of a B is formed in a…
Games · Amusements · Sports · Recreation · Pets
Internet Archive · Harold B. Lee Library · Public domain (published before 1931). Free to use for anything.
