When we consider the millions of comets around us, and when we
remember how near some of these have come to us during the last few
years, who will undertake to say that during the last thirty
thousand, fifty thousand, or one hundred thousand years, one of these
erratic luminaries, with blazing front and train of _débris_, may not
have come in collision with the earth?

{p. 91}

CHAPTER IV.

THE CONSEQUENCES TO THE EARTH.

IN this chapter I shall try to show what effect the contact of a
comet must have had upon the earth and its inhabitants.

I shall ask the reader to follow the argument closely first, that he
may see whether any part of the theory is inconsistent with the
well-established principles of natural philosophy; and, secondly,
that he may bear the several steps in his memory, as he will find, as
we proceed, that _every detail of the mighty catastrophe has been
preserved in the legends of mankind_, and precisely in the order in
which reason tells us they must have occurred.

In the first place, it is, of course, impossible at this time to say
precisely how the contact took place; whether the head of the comet
fell into or approached close to the sun, like the comet of 1843, and
then swung its mighty tail, hundreds of millions of miles in length,
moving at a rate almost equal to the velocity of light, around