V. THE LEADING MEMBERS OF OUR FAMILY.--SECOND GROUP, 55 VI. THE MOON, 62 VII. VISITORS, 73 VIII. LITTLE SERVANTS, 83 IX. NEIGHBORING FAMILIES, 95 X. OUR NEIGHBORS’ MOVEMENTS, 106 XI. MORE ABOUT THE SOLAR SYSTEM, 122 XII. MORE ABOUT THE SUN, 133 XIII. YET MORE ABOUT THE SUN, 148 XIV. MORE ABOUT THE MOON, 157 XV. YET MORE ABOUT THE MOON, 164 XVI. MERCURY, VENUS, AND MARS, 180 XVII. JUPITER, 199 XVIII. SATURN, 214 XIX. URANUS AND NEPTUNE, 225 XX. COMETS AND METEORITES, 240 XXI. MORE ABOUT COMETS AND METEORITES, 246 XXII. MANY SUNS, 267 XXIII. SOME PARTICULAR SUNS, 278 XXIV. DIFFERENT KINDS OF SUNS, 291 XXV. GROUPS AND CLUSTERS OF SUNS, 304 XXVI. THE PROBLEM OF SUN AND STAR DISTANCES, 310 XXVII. MEASUREMENT OF STAR DISTANCES, 320 XXVIII. THE MILKY WAY, 329 XXIX. A WHIRLING UNIVERSE, 337 XXX. READING THE LIGHT, 344 XXXI. STELLAR PHOTOGRAPHY, 355 XXXII. THE DAWN OF ASTRONOMY, 363 XXXIII. MODERN ASTRONOMY, 375 XXXIV. SIR ISAAC NEWTON, 382 XXXV. LATER ASTRONOMY, 393 LIST OF ILLUSTRATIONS. PAGE. Hipparchus in the Observatory at Alexandria _Frontispiece._ The Solar System 15 The Pleiades 19 Sun-spots 29 Phases of Mercury before Inferior Conjunction--Evening Star 50 Appearance of the Full Moon 63 One Form of Lunar Crater 69 The Earth as Seen from the Moon 71 Passage of the Earth and the Moon through the Tail of a Comet 76 Passage of the Comet of 1843 Close to the Sun 79 Meteor Emerging from Behind a Cloud 84 The Great Shower of Shooting-stars, November 27, 1872 90 Constellation of the Great Bear 108 The Great Bear 50,000 Years Ago 109