Ragnarok : the age of fire and gravel

90 THE COMET.

that penetrate the remotest regions of the solar system, and eyen beyond it.

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 nndertake co say that during the last thirty thousand, fifty thousand, or one hundred thousand years, one of these erratie iuminaries, with blazing front and train of débris, may pot have come in collision with the earth?