the original comet of Biela. This brings us to the second branch of
our subject.

More rare than meteors or falling stars, and more startling, except
that they never appear in showers, are the huge balls of fire which
occasionally dart through the sky, lighting up the landscapes beneath
with their glare, leaving trains of sparks behind them, often
producing peals of thunder when they explode, and in many cases
falling upon the earth and burying themselves from a few inches to
several feet in the soil, from which, more than once, they have been
picked up while yet hot and fuming. These balls are sometimes called
bolides. They are not really round in shape, although they often look
so while traversing the sky, but their forms are fragmentary, and
occasionally fantastic. It has been supposed that their origin is
different from that of the true meteors; it has even been conjectured
that they may have originated from the giant volcanoes of the moon or
have been shot out from the sun during some of the tremendous
explosions that accompany the formation of eruptive prominences. By
the same reasoning some of them might be supposed to have come from
some distant star. Others have conjectured that they are wanderers in
space, of unknown origin, which the earth encounters as it journeys
on, and Lord Kelvin made a suggestion which has become classic because
of its imaginative reach -- viz., that the first germs of life may
have been brought to the earth by one of these bodies, ``a fragment of
an exploded world.''

It is a singular fact that astronomers and scientific men in general
were among the last to admit the possibility of solid masses falling
from the sky. The people had believed in the reality of such phenomena
from the earliest times, but the savants shook their heads and talked