Arago estimated that the comets belonging to the solar system, within the orbit of Neptune, numbered seventeen million five hundred thousand!
Lambert regards five hundred millions as a very moderate estimate![1]
[1. Guillemin, "The Heavens," p. 251.]
{p. 83}
And this does not include the monstrous fiery wanderers who may come to visit us, bringing their relations
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ORBITS OF THE PERIODIC COMETS.
along, from outside the solar system--a sort of celestial immigrants whom no anti-Chinese legislation can keep away.
Says Guillemin:
"Leaving mere re-appearances out of the question, new comets are constantly found to arrive from the depths of space, describing around the sun orbits which testify to the attractive power of that radiant body; and, for the