Sun’s Heat, Is it decreasing?, 65. Sun’s Rays increasing the Strength of Magnets, 196. Sun’s Light and Terrestrial Lights, 61. Sun-dial, Universal, 65. Telegraph, the Atlantic, 226. Telegraph, the Electric, 220. Telescope and Microscope, the, 38. Telescope, Galileo’s, 93. Telescope, Herschel’s, 95. Telescope, Newton’s first Reflecting, 94. Telescopes, Antiquity of, 94. Telescopes, Gigantic, proposed, 99. Telescopes, the Earl of Rosse’s, 96. Temperature and Electricity, 208. Terrestrial Magnetism, Origin of, 200. Thames, the, and its Salt-water Bed, 182. Threads, the two Electric, 215. Thunderstorm seen from a Balloon, 169. Tides, How produced by Sun and Moon, 66. Time an Element of Force, 19. Time, Minute Measurement of, 194. Topaz, Transmutation of, 37. Trilobite, the, 138. Tuning-fork a Flute-player, 28. Twilight, Beauty of, 148. Universe, Vast Numbers in, 75. Utah, Salt Lake of, 113. Velocity of the Solar System, 59. Vesta and Pallas, Speculations on, 82. Vesuvius, Great Eruptions of, 119. Vibration of Heated Metals, 188. Visibility of Objects, 30. Voice, Human, Audibility of, 27. Volcanic Action and Geological Change, 118. Volcanic Dust, Travels of, 119. Volcanic Islands, Disappearance of, 117. Voltaic Battery and the Gymnotus, 206. Voltaic Currents in Mines, 206. Voltaic Electricity discovered, 205. Watches, Harrison’s Prize, 229. Water decomposed by Electricity, 208. Water, Running, Force of, 114. Waters of the Globe gradually decreasing, 113. Water-Purifiers, Natural, 234. Waterspouts, How formed in the Java Sea, 160. Waves, Cause of, 183. Waves, Force of, 184. Waves, Rate of Travelling, 183. Wenham-Lake Ice, Purity of, 161. West, Superior Salubrity of, 150. “White Water,” and Luminous Animals at Sea, 173. Winds, Transporting Power of, 163. Wollaston’s Minute Battery, 204. World, All the, in Motion, 11. World, the, in a Nutshell, 13. Worlds, More than One, 56. Worlds to come, 58. LONDON: ROBSON, LEVEY, AND FRANKLYN, GREAT NEW STREET AND PETTER LANE, E.C. Transcriber’s Notes Punctuation, hyphenation, and spelling were made consistent when a predominant preference was found in this book; otherwise they were not changed. Simple typographical errors were corrected; occasional unbalanced quotation marks retained. Ambiguous hyphens at the ends of lines were retained. Some numbers in equations include a hyphen to separate the fractional and integer parts. These are not minus signs, which, like other arithmetic operators, are surrounded by spaces. The original book apparently used a smaller font for multiple reasons, but as those reasons were not always clear to the Transcriber, smaller text is indented by 2 spaces in the Plain Text version of this eBook, and is displayed smaller in other versions.