with the year; and that the moon meantime must
pause in its outward flight, and come swinging back
on a descending spiral, until finally, after the lapse
of untold aeons, it ploughs and ricochets along the
surface of the earth, and plunges to catastrophic destruction.

But even though imagination pause far short of this
direful culmination, it still is clear that modern calculations,
based on inexorable tidal friction, suffice to
revolutionize the views formerly current as to the stability
of the planetary system. The eighteenth-century
mathematician looked upon this system as a vast celestial
machine which had been in existence about six
thousand years, and which was destined to run on forever.
The analyst of to-day computes both the past
and the future of this system in millions instead of
thousands of years, yet feels well assured that the solar
system offers no contradiction to those laws of growth
and decay which seem everywhere to represent the
immutable order of nature.


COMETS AND METEORS

Until the mathematician ferreted out the secret, it
surely never could have been suspected by any one that
the earth's serene attendant,

"That orbed maiden, with white fire laden,
Whom mortals call the moon,"