=II.= COMETS WHOSE PERIHELION DISTANCES ARE GREATER THAN 0.01 AND LESS THAN 0.05. Perihelion Passage. Per. Dist. Long. of Per. 1. 1689, Nov 29_d._ 4_h._ 0.0189 269° 41´ 2. 1816, March 1 8 0.0485 267 35 3. 1826, Nov 18 9 0.0268 315 31 4. 1847, March 30 6 0.0425 276 2 5. 1865, Jan 14 7 0.0260. 141 15 The perihelion of the first comet in Table III. is remote from the direction of the sun's motion; that of the second is distant but 14°, and of the third 21°. =III.= COMETS WHOSE PERIHELION DISTANCES ARE GREATER THAN 0.05 AND LESS THAN 0.1. Perihelion Passage. Per. Dist. Long. of Per. 1. 1593, July 18_d._ 13_h._ 0.0891 176° 19´ 2. 1780, Sept. 30 22 0.0963 246 35 3. 1821, March 21 12 0.0918 239 29 With greater perihelion distances the tendency of the perihelia to crowd together round the point indicated is less distinctly marked. 6. Few comets of small perihelion distance should have their perihelia in the vicinity of longitude 80°, the point opposite that towards which the sun is moving. Accordingly we find, by examining a table of cometary elements, that with a perihelion distance less than 0.1 there is not a single perihelion between 35° and 125°; between 0.1 and 0.2 but 3; and between 0.2 and 0.3 only 1. 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-- [11] Danville Quarterly Review, December, 1861. 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] [12] Others, it was supposed, might have originated within the system,--a view which the writer has not wholly abandoned. 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.