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 |
| The Great Bear 50,000 Years Hence | 109 |
| Constellation of Orion as it Appears Now | 110 |
| Constellation of Orion 50,000 Years Hence | 111 |
| Position of Planets Inferior to Jupiter—Showing the Zone of the Asteroids | 123 |
| Comparative Size of the Planetary Worlds | 130 |
| A Typical Sun-spot | 135 |
| A Solar Eruption | 138 |
| Sun-flames, May 3, 1892 | 143 |
| Solar Corona and Prominence | 152 |
| Comparative Size of the Earth and Sun | 155 |
| The Moon—an Expired Planet | 159 |
| The Lunar Crater Copernicus | 170 |
| Lunar Eruption—Brisk Action | 172 |
| Lunar Eruption—Feeble Action | 173 |
| Nicolaus Copernicus | 176 |
| Phases of Venus | 186 |
| Mars and the Path of its Satellites | 191 |
| General Aspect of Jupiter—Satellite and its Shadow | 200 |
| Satellites of Jupiter Compared with the Earth and Moon | 206 |
| The System of Jupiter | 208 |
| Orbits of Nine Comets Captured by Jupiter | 213 |
| Saturn and the Earth—Comparative Size | 215 |
| Ideal View of Saturn’s Rings and Satellites from the Planet | 222 |
| Great Astronomers of Earlier Times | 227 |
| The Great Comet of 1811 | 247 |
| Donati’s Comet, 1858 | 249 |
| Great Comet of 1744 | 254 |
| The First Comet of 1888—June 4 | 255 |
| Great Comet of 1680 | 260 |
| Great Comet of 1769 | 261 |
| Baron Alexander Von Humboldt | 264 |
| A Telescopic Field in the Milky Way | 270 |
| Cygnus, Constellation of | 279 |
| Stars whose Distances are Best Known | 281 |
| Lyra, Constellation of | 297 |
| Constellations in the Northern Hemisphere | 300 |
| A Cluster of Stars in Centaurus | 305 |
| The Great Nebula in Andromeda, Compared with Size of the Solar System | 307 |
| A Cluster of Stars in Perseus | 332 |
| Hercules, Constellation of | 338 |
| The Great Bear, Constellation of | 341 |
| The Prism and Spectrum | 344 |
| The Spectroscope | 345 |
| Spectra, Showing the Dark Lines | 347 |
| Great Astronomers of Later Times | 377 |
| Sir Isaac Newton | 386 |
| Eye-piece of Lick Telescope | 407 |
| Lick Observatory | 409 |
| Professor E. E. Barnard | 410 |