120 RECORD OF SCIENCE FOR 1886. 



His coDclusion, expressed with some reserve, is that 1873 VII and 1818 I 

 are distinct bodies, with a short jjeriod of revohitiou but having a com- 

 mon origin. Comet 1457 I is probably identical with 1873 VII, bat it is 

 also possible that the two comets 1873 VII and 1818 I are fragments of 

 1457 I. 



Comet 1877 VI. — Dr. Larssen, of Upsala, has completed the definitive 

 determination of parabolic elements of the comet discovered by Coggia 

 at Marseilles on September 14, 1877, and observed to December 10 of 

 that year. The observations have been newly reduced and combined 

 in five normal places, with a very satisfactory result. (Astron. Nachr. 

 116 : 23-26.) 



Comet 1881 V. — The close agreement of the elements with those of the 

 orbit of a comet discovered by Blanpain on the 28th of November, 1819, 

 has led to a conjecture that the two comets are identical, although Blan- 

 pp,iu's was computed to have a period of less than five years and Den- 

 ning's of nearly nine, it being supposed that planetary perturbation 

 had lengthened the period between the appearance of 1819 and that of 

 1881. It has been noticed both by Mr. Plummer and by Mr. Denning 

 that the longitude of the ascending node of the 1881 comet corresponds 

 almost exactly with that of the descending node of Biela's comet, which 

 has not been seen as a comet (or rather double comet) since 1852, though 

 it has been supposed to be connected with a very brilliant meteoric dis- 

 play seen on the 27th of November, 1872. The other elements of Den- 

 ning's comet exhibit a remarkable agreement with those of Biela's 

 comet ; and the suggestion in question is that these comets are identi- 

 cal, or rather that Denning's is identical witb the principal remaining 

 portion of Biela's, which underwent violent perturbation through near 

 approach to the earth in 1872, sufficient to lengthen its period and 

 reverse the nodes (a necessary consequence of altering the inclina- 

 tion through zero). Colonel Tupman, whose calculations well confirm 

 this theory, remarks " that on the 27th of November, 1872, it is prob- 

 able that the comet was very near the earth and mixed up with tlie 

 meteoric shower." The comet passed its perihelion on the 13th of Sep- 

 tember, 1881 ; the computed length of its period was 8.83 years, or about 

 3,225 days ; and this was almost exactly the interval which had elapsed 

 since the meteoric display of the 27th of November, 1872. If this theory 

 be true, we can not expect another similarly brilliant display on that 

 day until the year 1916, five periods of the comet's revolution in its or- 

 bit being very nearly equal to forty-four of the earth's. (AtheniBum.) 



Comet 1881 VIII. — Olsson finds a period of 612 years ; that founc^ by 

 Oppenheim was 2,740 years, though Oppenheim remarks that 900 years 

 would satisfy the observations almost as well. 



Comet 1882 II. — The valuable series of observations of this comet 

 made at the Cape of Good Hope, including the remarkable observation 

 of the disappearance of the comet at the limb of the sun, has been pub- 

 lished as vol. II, part 1, of the Annals of the Cape Observatory. Inter- 



