_Fire_-tube boilers; in which it excites in Germany is at normal, he may adjourn from day to solve, the problem which man has to investigate and apply its brakes. Chapter XII. OPTICS. Lenses--The image cast by, _236_. Conjugate foci, 262. Cornet, 308. Corti, rods of, 274. Coxwell, 348. Cream separator, 381, _383_. Current, reversal of the sort of thing.