VI. Parallel, diverging, and converging Rays 52 60 67 Conversation XIII. Concave and Convex Mirrors Page 101 XIV. Optical Deceptions, Anamorphoses, &c. 107 XXVII. Early History of Electricity XXVIII. Electrical Attraction and Repulsion XXXI. Electrical Attraction and Repulsion trical Battery - - 211 217 226 234 242 254 259 268 |