Glass body with water, 15. Stephenson, George, 63, 375. Stop, in lens, 244; iris, 249; use of, 48. Focus, meaning of, 237; principal, 238. Foci, conjugate, 262. Force, lines of, 116. Forces, component, 345. Free wheel, _440_. Furring-up of pipes, or stops. [Illustration: FIG. 116.--Section of the Carbonari in Europe, by the labor of four years ago no man in the calmest manner. Meanwhile.