Telescopes: many, 17; best, 134; alone, 227, 230; use, 233, 234. Temperature, 101, 102, 108; of space, 224, 227. Terminator, 147. Thermometer, 71, 93, 102; low, 160, 163. Time, small divisions, 241. Tippoo Saib, 221. Total Eclipse (_q. v._), 39–48 _passim_, 55, 59. Trees, lacking, 168. Tribune, The New York, 84. Trinity Church, 72. Trocadéro, 112. Trouvelot, E. L., 119, 123, 225. Turin, 38. Twilight, small, 38. Tycho, 144, 229. (See _Star_.) Tyndall, 98. Umbra, 11, 12, 19, 20. United States, comparison, 24. Uranus, 3, 196. Vapor, 28. Vega, 235, 246. Vegetables, 74. Veils, 14, 17. Venus, 118. Vernier, 3. Vesuvius: crater, 155, 157; eruption, 181, 183. (See _Naples_.) Vibrations, 72. Victoria, 115. Viscous Fluid, 26. Vital Force, 14. Vogel, H. C., 64, 66. Voids, 181, 227. Volcanoes, 27, 28; in moon, 167, 193. Wandering Star, 101. (See _Comets_, _Falling_.) Washington: Observatory, 2, 86–88; telescope, 122; Monument, 182. Water, 152; in man, 221. Waterloo, 80. Water-wheel, 111. Watson’s Observations, 49. Wheat, prices, 79. (See _Breadstuffs_, _Corn_, _Grain_, _Sun-spots_.) Wheel, comparison, 10. Whirlpools, 28, 31. Whirlwinds, 23, 31. White Light (_q. v._), 48, 62, 63. Whitney, Mount, 177. Willow-leaves (_q. v._), 11, 12, 14. Wing, simile, 215. Winlock, Professor, 44. Withered Surfaces, 168, 171. Wood-engraving, 50. Worlds and Clouds, 249. Wrinkles, 172. Xeres, Spain (_q. v._), 44, 53. Young, Professor: spectroscope, 44, 50, 65, 234; observations, 56, 59, 61, 68, 69; magnetism, 87, 88; radiation, 101. Zodiacal Light, 55. University Press: John Wilson & Son, Cambridge. Transcriber’s Notes Punctuation, hyphenation, and spelling were made consistent when a predominant preference was found in the original book; otherwise they were not changed. Simple typographical errors were corrected; unbalanced quotation marks were remedied when the change was obvious, and otherwise left unbalanced. Illustrations in this eBook have been positioned between paragraphs and outside quotations. In versions of this eBook that support hyperlinks, the page references in the List of Illustrations lead to the corresponding illustrations. The index was not checked for proper alphabetization or correct page references.