338 THE POPULAR SCIENCE MONTHLY. 



It is proper to remark, however, that Newton's period of the meteora 

 exceeds Oppolzer's period of the comet by twenty-seven days, and 

 that each is liable to some uncertainty. But for the authority of thi 

 distinguished French astronomer, the writer would have fixed upon the 

 year 43 b. c. as the probable epoch at which the cometary mass was 

 thrown into its present orbit. Be this as it may, it undoubtedly suf- 

 fered considerable perturbation about a. d. 126. 



The question of the planetary disturbance of the meteor-streams is 

 one of great interest. The November group has its perihelion at the 

 orbit of the earth ; its aphelion at that of Uranus. Both planets, 

 therefore, at each encounter with the current not only appropriate a 

 portion of the meteoric matter, but entirely change the orbits of a 

 large number of meteors. In regard to the devastation produced 

 by the earth in passing through the cluster, it is sufficient to state 

 that, according to Weiss, the meteor orbits resulting from the 

 disturbance will have all possible periods from 21 months to 390 

 years. It may be regarded, therefore, as an additional evidence 

 of the recent introduction of this meteor-stream into the solar system 

 that the comet of 1866, which constitutes a part of the cluster, has not 

 been deflected from the meteoric orbit by either the earth or Uranus. 

 It is, moreover, interesting to remark that the comet and Uranus will 

 be in close proximity about the year 1983 ; perhaps so close as to 

 throw the former into a new orbit. 



As the comets 1862, III., and 1866, 1., were doubtless more brilliant 

 in ancient than in modern times, and as the former was conspicuously 

 visible to the naked eye, it seems not improbable that they may have 

 been formerly observed. The epochs of their ancient returns agree in 

 several instances with those of comets of which the recorded observa- 

 tions are insufficient to determine their elements. 



The writer as long since as 1861 suggested the probable disintegra- 

 tion of Biela's comet and the distribution of its matter around the 

 orbit. 1 The earth crosses the path of these cometary fragments about 

 the 29th or 30th of November a well-known aerolitic epoch. It is 

 also worthy of notice that an extraordinary number of shooting-stars 

 was observed by M. Heis, at Aix-la-Chapelle, on the 29th of Novem- 

 ber, 1850. 



From the fact that the earth, about the 20th of April, very nearly 

 crosses the orbit of the comet 1861, I., a connection between the latter 

 and the meteors of that epoch has been suggested by some astrono- 

 mers. The period of the comet is, according to Oppolzer, 415 years. 

 The first recorded shower of the April meteors occurred in the year 

 687 b. c. ; the last great display in 1803 a. d. The interval is equal 

 to six periods of 415 years. It is evident, however, that, if these mete- 

 ors and the first comet of 1861 originally constituted a single group, 



1 Danville Quarterly JReview, December, 1861. See also "Meteoric Astronomy," pp 

 64, 55, 126-128. 



