star, wherever it may be situated, is attracted by its fellow-stars
from many sides at once, and although the force is minimized by
distance, yet in the course of many ages its effects must become
manifest.

Looked at from another side, is there not something immensely
stimulating and pleasing to the imagination in the idea of so
stupendous a journey, which makes all of us the greatest of travelers?
In the course of a long life a man is transported through space thirty
thousand million miles; Halley's Comet does not travel one-quarter as
far in making one of its immense circuits. And there are adventures on
this voyage of which we are just beginning to learn to take account.
Space is full of strange things, and the earth must encounter some of
them as it advances through the unknown. Many singular speculations
have been indulged in by astronomers concerning the possible effects
upon the earth of the varying state of the space that it traverses.
Even the alternation of hot and glacial periods has sometimes been
ascribed to this source. When tropical life flourished around the
poles, as the remains in the rocks assure us, the needed high
temperature may, it has been thought, have been derived from the
presence of the earth in a warm region of space. Then, too, there is a
certain interest for us in the thought of what our familiar planet has
passed through. We cannot but admire it for its long journeying as we
admire the traveler who comes to us from remote and unexplored lands,
or as we gaze with a glow of interest upon the first locomotive that
has crossed a continent, or a ship that has visited the Arctic or
Antarctic regions. If we may trust the indications of the present
course, the earth, piloted by the sun, has come from the Milky Way in
the far south and may eventually rejoin that mighty band of stars in
the far north.