most part, going away for centuries, to return again from afar after
their immense revolutions."[1]

But do these comets come anywhere near the orbit of the earth?

Look at the map on the preceding page, from Amédée Guillemin's great
work, "The Heavens," page 244, and you can answer the question for
yourself.

Here you see the orbit of the earth overwhelmed in a complication of
comet-orbits. The earth, here, is like a lost child in the midst of a
forest full of wild beasts.

And this diagram represents the orbits of only six comets out of
those seventeen millions or five hundred millions!

It is a celestial game of ten-pins, with the solar system for a
bowling-alley, and the earth waiting for a ten-strike.

In 1832 the earth and Biela's comet, as I will show more particularly
hereafter, were both making for the same spot, moving with celestial
rapidity, but the comet reached the point of junction one month
before the earth did; and, as the comet was not polite enough to wait
for us to come up, this generation missed a revelation.

"In the year 1779 Lexell's comet approached so near to the earth that
it would have increased the length of the sidereal year by three
hours if its mass had been equal to the earth's."[2]

And this same comet did strike our fellow-planet, Jupiter.