INDEX. 



Snow, what it is, 639. 

 Soap, how made, 391. 

 Soap-bubbles, Notes on, 98. 

 Sodium, 392, 437. 



,, Experiments with, 317. 

 Solar chronometers, 563. 



,, spectrum, The, 143. 

 Solid, Definition of, 4. 

 Solitaire, explanation of puzzles, 736. 



, , The game of, 735. 

 Solstices, Equinoxes and, 496. 

 Sound impossible without air, iC3. 

 ,, Intensity of, 171. 

 ,, Reflection of, 171. 

 Refraction of, 171. 

 transmitted by solids, 174. 

 Velocity of, 169. 

 Velocity of, varies, 170. 

 what it is, 167. 

 ,, whence it arises, 167. 

 Sound-waves, Nodes of, 169. 



,, to see, 173. 



Sounds, musical and unmusical, 167. 

 Sources of heat, 77. 

 Space, what it is, 4. 

 Spar, Derbyshire, 395. 

 Spark, Electric duration of, 213. 

 ,, Light of an electric, 119. 

 Speaking tubes, 172. 

 Specific gravity, 68. 



,, Huxley's definition of, 70. 

 , , of metals, 389. 

 Specific heat, 88. 



Spectacles, Different glasses for, i -o. 

 Spectra, Composition of, 147. 



,, ocular, 143. 

 Spectral illusions, 161. 

 Spectre, a visible, 161. 



of the Brocken, The, 650. 

 Spectres, Impalpable, 126. 

 ,, M. Robin's, 138. 

 Spectroscope, Discovery of the, 145. 



,, Uses of the, 145. 



Spectroscopy, Science of, 145. 

 Spectrum analysis, 145. 

 ,, heat, 146. 

 ,, solar, 143. 

 Sphericity, Aberration of, 105. 

 Spider tribe, The, 723. 

 Sponges, Nature of, 706. 



,, Reproduction of, 706. 

 Spots, Sun, 498. 

 Springs, Causes of, 604. 

 Squares, Magic, 731. 

 Stamens, The, 677. 



Uses of, 665. 

 Starch, Notes about, 417. 

 Star, pole, The, ^94. 

 Star-fish, 713. 

 Stars, Clusters of, 551. 



,, Colours of the, 548. , 



,, Distance of the, 544. 

 ,, Double and multiple, 546. . 

 ,, Falling, 490. 

 Fixed, 535. 

 Lost, 550. 



Magnitude of the, 554. 

 Motions of, 535. 

 New, 550. 



Number of the, 536. 

 Radiating form of, 105. 

 Showers of, 491. 

 State, Changes of, produced by heat, 



89. 



Static electricity, 209. 

 Steam, Definition of, 91. 



,, Tree-felling by, 766. 

 Steamer, The smallest, 773. 



Stem, Parts of the, 667. 

 The, 667. 

 ,, Varieties of the, 667. 

 Stems, Tree, 668. 

 Stereoscope, Principle of the, 141. 



,, Reflecting, 141. 



,, Refracting, The, i.' r i. 



Stone, Pudding, 568. 

 Stories, Ghost, 161. 

 Strata, List of geological, 573. 

 Strepsiptera, The, 721. 

 Strings, Vibration of, 170. 

 Strontium, 395, 438. 

 Strontium, Luminous sulphates, 333. 

 Structure of plants, 661. 

 Strychnine, 416. 

 Sublimation and distillation, 86. 

 Substances, Indifferent, 417. 

 Substances, Nitrogenous, 422. 

 Sucker, The school-boy's, 48. 

 Sugar, Refining of, 418. 

 Sulphur, Mineral, 435. 

 ,, Uses of, 379. 

 Sun, Density of the, 503. 



Distance of the, 503. 



Eclipses of the, 519. 



Form of the, 498. 



Motion of the, 496. 



Power of the, 503. 



Spots on the, 498. 



Volume of the, 503. 

 Suns, mock, Cause of, 648. 

 Sunset, Colours of the, 655. 

 Surfaces, luminous, Laws of, 107. 

 Swan lamps, The, 271. 

 Swimming, New apparatus for, 458. 

 Swing, Simple child's, 763. 

 Symbols, Chemical table of, 308. 

 Synthesis of movements, 125. 

 Syphon recorder, Thomson's, 244. 

 Syren, The, 194. 

 Syringes, An effect of atmospheric 



pressure, 63. 

 System, Cambrian, 575. 

 Coal, 578. 

 Devonian, 576. 

 Laurentian, 573. 

 Silurian, 575. 

 The Solar, 487. 

 Systems, Palaeozoic, 573. 



Tablelands, Plateaus or, 626. 

 Tadpoles in aquaria, 10. 

 Talking head, How to work, 135. 

 Tangent galvanometer, The, 227. 

 Tanning, 414. 

 Tanning, Process of, 414. 

 Tap, A new kind of, 762. 

 Tape-worms, 716. 

 Tar, Uses of, 378. 

 Taurus, Constellation, 537. 

 Telegraph, Automatic, 243. 



,, electric, Discovery of, 232. 



,, ,, Ordinary form of 



2 34- 



Telegraphic system, New, 244. 

 Telegraphs, Early, 232. 

 Telegraphy, Practical, 239. 



,, Submarine, 243. 



Telephone, Description of the, 186. 



Invention of the, 186. 



Telescope, Achromatic, 149. 



,, Description of the, 147. 



,, Divided, explained, 135. 



,, Introduction of the, 469. 



,, reflector, The, 149. 

 Telescopes, 149. 

 Tellurium, 386. 



Terminations, Chemical, 337. 

 Tertiary period, The, 591. 

 Thaumatrope, The, no, 121. "'. 

 Theatre, The praxinoscope, 125. 

 Theory, atomic, The, 309. 

 Thermo-dynamics, Definition of, 73. 

 Thermometer, How to make a, 79. 

 ,, Invention of the, 78. 



Thermometers, Alcoholic, 80. 

 Thunder, Causes of, 291. 

 Thunderstorms, Precautions, 233. 

 Tides, Ebb and flow of, 612. 



,, Influence of the moon, 517. 



,, Science of the, 614. 

 Time, Ancient measurements of, 479, 



,, Equation of, 482. 



Sidereal, 478. 

 Tin, Crystallization of, 324. 



,, Uses of, 403, 446. 

 Tissues, Cellular and vascular, 66 1. ' 

 Top, The dazzling, 128. 



,, The magic, 740. 

 Topophone, Description of the, i3o. 



,, Invention of the, 180. 



Tops, Chromatic, 109. 



,, in optical physiology, 108. 

 Torpedo, Electricity of the, 285. 

 Torsion electrometer, The, 209. 

 Towers, leaning, Laws of, 33. 

 Toys, Electric, 279. 



,, Simple, 764. 

 Tramways, Electric, 272. 

 Transit, Curious modes of, 770. 

 ,, instrument, How to use, 

 Trapeze, Simple home-made, 762 

 Tree-felling, Steam power for, 7' 



,, frogs, n. 

 Trias, The, 585. 



,, Upper and lower, 585. 

 Trolly-sailing, 465. 

 Trumpets, Speaking, 172. 

 Tube, Galileo's, 148. 

 Tube well, The, 455. 

 Tuber, Definition of the, 667. 

 Tubes, Speaking, 172. 

 Tuning-fork, The, 193. 

 Type casting, 405. 



,, metal, 404. 



Union, Chemical, involves he. ui. 

 Uranus, The planet, 533. 

 Vacuum, Torricellian, 51. 

 Vanessa algina, 16. 

 Vapour, Clouds and, 634. 



,, what it is, 629. 

 Variations of the compass, 257. 

 Varnishes, 421. 

 Vascular tissues, 661. 

 Vehicle, A new two-wheeled, 770, 

 Velocipede, New water, 461. 

 Velocipedes, Ancient, 775. 

 Velocity, Acceleration of, 41. 



Definition of, 23. 



Facts about, 23. 



of Electricity, 212. 



of light, 94. 



Retarded, 41. 

 Ventilation, Notes on, 344. 

 Venus, The planet, 522. 

 Vessels, connected, Laws of, 62. 

 Vesta, Discovery of, 528. 

 Views, Dissolving, 160. 

 Vinegar, how prepared, 418. 

 Virgo, Constellation, 538. 

 Vision, Binocular, 141. 

 ,, Definition of , '103. 

 ,, Field of, 140. 

 , , The eye and, 140. 



