1. 



b.c. 687. 



2. 



,, 15. 



3. 



a.d. 582. 



Intelligence and Miscellaneous Articles, 395 



between the meteors and the comet, similar to that recently detected 

 between the November meteors and the comet of 1866, was thus sug- 

 gested as probable. Is this hypothesis in harmony with facts ? and if 

 not, are our present data sufficient for determining with any reason- 

 able probability the true period of the April meteors ? 



Dates of the April Shower. — Professor Newton selects the follow- 

 ing from Quetelet's Catalogue as belonging to this period* : 



4. a.d. 1093, 1094, 1095, and 1096. 



5. „ 1122, 1123. 



6. „ 1803. 



Period of the First Comet of 1861.-— The elements of this body 

 were computed by Oppolzer, who assigned it a period of 415y*4. 

 Now, while it is true that the interval from b.c 687 to a.d. 1803 is 

 very nearly equal to 6 periods of 415 years, the slightest examina- 

 tion will show that this period does not harmonize with any of the 

 intermediate dates. This fact, then, without further discussion, 

 seems fatal to the hypothesis that the period of the meteors is nearly 

 equal to that of the comet. 



What is the probable period of the ring ? — The showers of 1093-96 

 and 1122-23 at once suggest a period of from 26 to 30 years. The 

 nodal passage of the densest portion of the ring at the former epoch 

 may be placed anywhere between 1093 and 1096, and that of the 

 latter in either 1122 or 1123. The entire interval from b.c 687 

 to a.d. 1803 is 2490 years, or 88 periods of 28^295 each ; and the 

 known dates are all satisfied by the following scheme ; — 



b.c. 687 to b.c. 15 672-000 years=24 periods of 18-000 y each. 



15 to a.d. 582 597-000 „ =21 „ 28-429 



a.d. 582 to „ 1093-714 511714 „ =18 „ 28 429 



„ 1093-714 to „ 1122-143 28-429 „ = 1 „ 28-429 



„ 1122143 to ,, 1803 680 857 „ =24 „ 28369 „ 



These coincidences indicate a period of about 28^ *j* years, corre- 

 sponding to an ellipse whose major axis is 18*59. Hence the dis- 

 tance of the aphelion is very nearly equal to the mean distance of 

 Uranus. It will also be observed that the time of revolution, which 

 seems to have been somewhat lengthened about the Christian era, 

 was previously one third of the period of Uranus. 



II. The Meteors of December llth-YMh. 



In the catalogue of Quetelet we find the four following extraor- 

 dinary displays which belong undoubtedly to this period. Obser- 

 vations made in England, 1862, indicate also a more than ordinary 

 number of meteors at the December epoch in that year. 



1. a.d. 901. '* The whole hemisphere was filled with those me- 

 teors called falling stars, the ninth of Dhu'lhajja (288th year of the 

 Hegira) from midnight till morning, to the great surprise of the be- 

 holders in Egypt." — Modern part of the Universal History, 8vo, 

 vol. ii. p. 281. Lond. 1780. The date of this phenomenon corre- 

 sponds to the December epoch, a.d. 901. 



2. 930. "Averse remarquable d'etoiles filantes en Chine." 



3. 1571. " On vit a Zurich * du feu tomber du ciel.' " 

 * Silliman's Journal for July 1863. 



t Herrick assigned a value of 27 years. See Silliman's Journal for 

 April 1841, p. 365. 



