Electrical battery, 387 Electro-magnetism, 413 Electro-magnets, 414 Electric telegraph, 415 Equestrian feat, 185 Equilibrium, stable and unstable, 109 Evaporation, 286 Evaporation, cold produced by, 326 Expansion by heat, 274 Expansion, exception to it, 330, 331 Extension, a property of matter, 44 Eye, description of, 353 Eye, images in, inverted, 356 Feathers, how a non-conductor of heat, 305 Fire-engine, 179 Flexibility, 29 Flies, feet of, 157 Force, relation of, to velocity, 194 Forcing-pumps, 178 Franklin, his theory of electricity, 373 Franklin, his discovery, 392 Freezing, process of, described, 330 Freezing point, why at 32°, 332 Freezing in the midst of boiling, 327 Freezing mercury, 318 Freezing mixtures, 325 Friction, 196-198 Friction in machinery, 245 Frost, 44 Fur, how a non-conductor of heat, 305 Fur, how altered by climate, 305 Fusee of a watch, 238 Galvanism, 394 Gases, movements of the particles in, 10 Gases, space in, 21 Gases, compressibility of, 38 Gasometer, 163 Glass, annealing of, 32 Glass-making, centrifugal force used in, 216 Governor, steam, 217 Gravitation, 79, 86 Gravitation, limiting size, 90 Gravitation, action of, on solids in a liquid, 136 Gravity, specific, defined, 135 Gridiron pendulum, 210 Gunnery, retardation by condensed air in, 166 Hail, how produced, 290 Hardness, 28 Harmony, 266 Hearing, mysteries of, 269 Hearing, trumpet, 262 Heat, nature of, 271 Heat, sources of, 272 Heat, relations of, to forms of matter, 13 Heat, relation of, to bulk of liquids, 37 Heat, relation of, to light, 273 Heat producing expansion, 274, 275, 279 Heat, communication of, 295 Heat, convection of, 296 Heat, conduction of, 297 Heat, radiation of, 311 Heat, reflection of, 314 Heat, connection of, with light, 312 Heat, production of, by electricity, 391 Heat, degree of, endurable by man, 328 Heat, latent, 319 Heat, capacity of different substances for, 320 Heat, relation of, to density, 321 Heat, relation of, to forms of substances, 323 Heat and cold, 270 Heights measured by barometer, 170 Hume, his ideas of matter, 3 Hydrometer, 144 Hydrostatics, what it teaches, 110 Hydrostatic balloon, 159 Hydrostatic bellows, 132 Hydrostatic paradox, 131 Hydrostatic press, 133 Ice, formation of, 329 Ice, force of its expansion, 333 Ice-crystals, colors in, 367 Icebergs, centre of gravity in, 145 Impenetrability, 45 Imponderable agents, 16 Inclined plane, 241 Induction in electricity, 379 Induction in magnetism, 400 Inertia, 48 Inertia shown in the communication of motion, 183 Inertia shown in disposition of motion to continue, 184 Insulating stool, 382 Jupiter, mountains in, 92 Kaleidoscope, 343 Laggan stones, 100 Land-breeze, 283 Lenses, 349