CHAPTER VI.
THE DISINTEGRATION OF COMETS.
The fact that in several instances meteoric streams move in orbits identical with those of certain comets was first established by the researches of Signor Schiaparelli. The theory, however, of an intimate relationship between comets and meteors was advocated by the writer as long since as 1861,[11]—several years previous to the publication of Schiaparelli's memoirs. In the essay here referred to it was maintained—
1. That meteors and meteoric rings "are the débris of ancient but now disintegrated comets whose matter has become distributed around their orbits."
2. That the separation of Biela's comet as it approached the sun in December, 1845, was but one in a series of similar processes which would probably continue until the individual fragments would become invisible.
3. That certain luminous meteors have entered the solar system from the interstellar spaces.[12]
4. That the orbits of some meteors and periodic comets have been transformed into ellipses by planetary perturbation; and
5. That numerous facts—some observed in ancient and some in modern times—have been decidedly indicative of cometary disintegration.
What was thus proposed as theory has been since confirmed as undoubted facts. When the hypothesis was originally advanced, the data required for its mathematical demonstration were entirely wanting. The evidence, however, by which it was sustained was sufficient to give it a high degree of probability.
The existence of a divellent force by which comets near their perihelia have been separated into parts is clearly shown by the following facts. Whether this force, as suggested by Schiaparelli, is simply the unequal attraction of the sun on different parts of the nebulous mass, or whether, in accordance with the views of other astronomers, it is to be regarded as a cosmical force of repulsion, is a question left for future discussion.