Part 2

XVI. The Surface of the Sun 113

XVII. The Solar System 119

XVIII. The Origin of the Earth 127

XIX. Jupiter and His Nine Moons 139

XX. The Rings and Moons of Saturn 148

XXI. Is the Moon a Dead World 156

XXII. Comets 165

XXIII. Meteorites 173

XXIV. The Earth As a Magnet 183

XXV. Some Effects of the Earth's Atmosphere Upon Sunlight 193

XXVI. Keeping Track of the Moon 207

XXVII. The Motions of the Heavenly Bodies 216

XXVIII. The Evolution of the Stars--From Red Giants to Red Dwarfs 225

XXIX. Double and Multiple Stars 230

XXX. Astronomical Distances 241

XXXI. Some Astronomical Facts Worth Remembering 250

ILLUSTRATIONS

PAGE

Northern Portion of the Moon at Last Quarter Frontispiece

The Great Hercules Cluster--A Universe of Suns facing page 56

A Dark Nebula: The Dark Bay or Dark Horse Nebula in Orion facing page 110

A. Venus. B. Mars. C. Jupiter. D. Saturn facing page 122

Spiral Nebula in Canes Venatici facing page 216

Spiral Nebula in Andromeda Viewed Edgewise facing page 222

LIST OF TABLES

PAGE

I. The Principal Elements of the Solar System 261

II. The Satellites of the Solar System 262