"How do you account for that living world," Bearwarden asked
Cortlandt, "on your theory of size and longevity?"

"There are two explanations," replied Cortlandt, "if the theory,
as I still believe, is correct. Hilda has either been brought to
this system from some other less matured, in the train of a
comet, and been captured by the immense power of "Jupiter, which
might account for the eccentricity of its orbit, or some accident
has happened to rejuvenate it here. A collision with another
minor planet moving in an orbit that crossed its own, or with the
head of a large comet, would have reconverted it into a star,
perhaps after it had long been cold. A comet may first have so
changed the course of one of two small bodies as to make them
collide. This seems to me the most plausible theory. Over a
hundred years ago the English astronomer, Chambers, wrote of
having found traces of atmosphere in some of these minor planets,
but it was generally thought he was mistaken. One reason we know
so little about this great swarm of minor planets is, that till
recently none of them showed a disk to the telescope. Inasmuch
as only their light was visible, they were indistinguishable from
stars, except by their slow motion. A hundred years ago only
three hundred and fifty had been discovered; our photographic
star-charts have since then shown the number recorded to exceed
one thousand."


CHAPTER IV.

PREPARING TO ALIGHT.