Page:The Solar System - Six Lectures - Lowell.djvu/39



conclusion which is correct in quality: that the number of hyperbolic orbits to elliptic should be very small, less than one in the whole number already seen, on the tacit assumption that the Sun was at rest.

But the Sun is not at rest. It is traveling at the rate of eleven miles a second towards a point in the constellation Hercules, carrying its retinue with it; and this motion quite alters the result. Instead of a great preponderance of elliptic orbits, the solution shows in this case a large excess of hyperbolic ones. And in most of the orbits the hyperbolicity would be marked, not faint and doubtful. To Schiaparelli we owe the first suggestion of this fact, and, in 1895, to Fabry, of the observatory of Marseilles, a very elegant and conclusive memoir on the subject.

In view of this we see that comets behave not as they would, did they come to us as visitors from other stars, but just as they should, considered as distant members of our own system. Comets, then, are also all co-members of the system.

That there is quite room enough within the Sun's paramount domain for their gigantic orbits becomes evident when we consider the distance to which that domain extends. Measured even