| PAGE | |
| Fig. 1.—The Milky Way | 46 |
| Photo by Easton. | |
| Fig. 2.—Planetary Nebula No. 7009, New General Catalogue | 52 |
| Fig. 3.—Nebula No. 4594, New General Catalogue | 66 |
| Fig. 4.—Nebula No. 101 in Messier’s Catalogue | 70 |
| Fig. 5.—Nebula No. 51 in Messier’s Catalogue | 71 |
| Fig. 6.—Milky Way Between Cassiopeia and Swan | 76 |
| According to Wolf. | |
| Fig. 7.—Milky Way in Eagle and Sagittarius | 76 |
| According to Wolf. | |
| Fig. 8.—The “trifid” Hole in Eagle | 77 |
| According to Wolf. | |
| Fig. 9.—Tarim River With Lakes and Bayirs | 96 |
| According to Sven Hedin. | |
| Fig. 10.—The Former Lake Bonneville in Utah | 106 |
| Fig. 11.—Jupiter, 1909 | 122 |
| According to F. le Coultre. | |
| Fig. 12.—Saturn, 1909 | 123 |
| According to F. le Coultre. | |
| Fig. 13.—Spectra of the Major Planets | 124 |
| According to V. M. Slipher. | |
| Fig. 14.—Venus Observed by Langley in 1882 | 136 |
| Fig. 15.—Rock Fissure at Hango, Sweden | 204 |
| Photo by I. I. Sederholm. | |
| Fig. 16.—Earthquake Centers in Calabria | 205 |
| According to I. I. Sederholm. | |
| Fig. 17.—Maps of Mars by Schiaparelli and Antoniadi | At the end |
| Fig. 17a.—Maps of Mars by Schiaparelli and Antoniadi | At the end |
| Fig. 18.—Photo of Mars by Lampland | 210 |
| Fig. 19.—Mars on April 8, 1909 | 210 |
| According to Quenisset. | |
| Fig. 20.—The South Pole Spot on Mars, 1909 | 210 |
| According to Jarry Desloges. | |
| Fig. 21.—Sandstorm on Mars, 1909 | 210 |
| According to Antoniadi. | |
| Fig. 22.—Cloud on Edge of Mars, the 7th of March, 1901 | 216 |
| According to Molesworth. | |
| Fig. 23.—Mars, July 11, 1907 | 216 |
| According to Lowell. | |
| Fig. 24.—Mars, October 6, 1909 | 216 |
| According to Antoniadi. | |
| Fig. 25.—Mercury | 230 |
| According to Lowell. | |
| Fig. 26.—The Moon near the Crater Tycho | 230 |
| Photo from Yerkes Observatory. | |
| Fig. 27.—Mare Serenitatis and Mare Tranquillitatis | 231 |
| Photo from Yerkes Observatory. | |
| Fig. 28.—The Moon near its South Pole | 240 |
| Photo from Yerkes Observatory. | |
| Fig. 29.—The Lunar Crater Copernicus and Vicinity | 242 |
| Photo from Yerkes Observatory. |