71, _72_; of Ruhmkorff coil, 123. Conduit, 176. Convex lens, image cast by, _236_. Conjugate foci, 262. Cornet, 308. Corti, rods of, 274. Coxwell, 348. Cream separator, 381, _383_. Current, reversal of the great principle of the Author of "The Romance of Modern Invention," pp. 166 foll. Chapter.