Three views of Saturn facing 186

Diagram showing the moon’s path through space 217

The lunar Alps, Apennines, and Caucasus facing 222

The moon at first and last quarter facing 226

Phases and rotation of the moon 250

Charts showing the zodiacal constellations: 
  1.  From right ascension 0 hours to 4 hours 259
  2. " " 4 " " 8 " 261
  3. " " 8 " " 2 " 263
  4. " " 12 " " 16 " 265
  5. " " 16 " " 20 " 267
  6. " " 20 " " 24 " 269

OTHER WORLDS

CHAPTER I

INTRODUCTORY

Other worlds and their inhabitants are remarkably popular subjects of speculation at the present time.  Every day we hear people asking one another if it is true that we shall soon be able to communicate with some of the far-off globes, such as Mars, that circle in company with our earth about the sun.  One of the masters of practical electrical science in our time has suggested that the principle of wireless telegraphy may be extended to the transmission of messages across space from planet to planet.  The existence of intelligent inhabitants in some of the other planets has become, with many, a matter of conviction, and for everybody it presents a question of fascinating interest, which has deeply stirred the popular imagination.

The importance of this subject as an intellectual phenomenon of the opening century is clearly indicated by the extent to which it has entered into recent literature.  Poets feel its inspiration, and novelists and romancers freely select other planets as the scenes of their stories.  One tells us of a visit paid by men to the moon, and of the wonderful things seen, and adventures had, there.  Lucian, it is true, did the same thing eighteen hundred years ago, but he had not the aid of hints from modern science to guide his speculations and lend verisimilitude to his narrative.

Another startles us from our sense of planetary security with a realistic account of the invasion of the earth by the terrible sons of warlike Mars, seeking to extend their empire by the conquest of foreign globes.

Sometimes it is a trip from world to world, a kind of celestial pleasure yachting, with depictions of creatures more wonderful than—­

    “The anthropophagi and men whose heads
    Do grow beneath their shoulders”—­

that is presented to our imagination; and sometimes we are informed of the visions beheld by the temporarily disembodied spirits of trance mediums, or other modern thaumaturgists, flitting about among the planets.