Page:Popular Science Monthly Volume 76.djvu/16

12 in any case, was a bold one but, fortunately for Halley's reputation and for science, the result fully justified it.

The same process has been tried in many cases besides this one, but this seems to be the only instance where the prediction has been verified by success. Gibbon gives us a very interesting instance of this method of identification. After referring to the remarks of Seneca, already quoted, he continues:

In more recent times we have the remarkable group of bodies of which the comets of 1668, 1843, 1882 are members; there are others, the total number being probably very large. All of these bodies move in orbits almost identical, almost grazing the surface of the sun at the time of perihelion passage, and passing through millions of miles of the