in a region of the universe more than sixty thousand millions of miles
from the place where it is now, so that since his time the whole human
race has been making a voyage through space, in comparison with which
his longest voyage was as the footstep of a fly.

Thus the great events in the history of the world may be said to have
occurred in different parts of the universe. An almost inconceivable
distance separates the spot which the earth occupied in the time of
Alexander from that which it occupied when Cæsar invaded Gaul. The sun
and the earth have wandered so far from their birthplace that the mind
staggers in the attempt to guess at the stupendous distance which now
probably separates them from it. It may be that the motion of the
solar system is orbital and that our sun and many of the stars, his
fellow suns, are revolving around some common center, but if so, no
means has yet been devised of detecting the form or dimensions of his
orbit. So far as we can see, the sun is moving in a straight line.

Since space is believed to be filled with some sort of ethereal
medium, curious consequences are seen to follow from the motions that
have been described. A solid globe like the earth rushing at great
speed through such a medium will encounter some resistance. If the
medium be exceedingly rare, as it must be in fact, the resistance will
be correspondingly small, but still there will be resistance. If the
sun stood still, the earth, owing to the inclination of its axis to
the plane of its orbit, around the sun, would encounter the resistance
of the ether principally on its northern hemisphere from summer to
winter, and on its southern hemisphere from winter to summer. But in
consequence of the motion of the sun shared by the earth, this law of
distribution is changed, and from summer to winter the earth plows
through the ether with its north pole foremost, while from winter to