Shooting Stars of December 7, 1838. 367 



both morning and evening. It may be found, that a constant dif- 

 ference exists in the directions and velocities of the meteors which 

 occur during the August season, and of those of the displays which 

 occur in November, December, and April. 



Enough appears to be already known to establish the proposi- 

 tion, that shooting stars are small bodies of various sizes, materi- 

 als and densities, revolving around the sun, and luminous in con- 

 sequence of the heat excited by their casual passage through our 

 atmosphere.* They have not inappropriately been termed by 

 M. Coquerel, microscopic planets. So far as we know, they have 

 the same astronomical relations as the larger luminous meteors call- 

 ed _^re-5a/fe, bolides^ meteorites, &c. They are encountered by the 

 earth's atmosphere probably every hour in the year, but in much 

 greater numbers at certain |)arts of the earth's orbit, than at others. 

 The distribution of these bodies throughout the solar system can 

 not yet be determined. The majority of them probably move in 

 groups, and may be supposed to constitute one or more broad 

 zones or rings, in some parts of which meteors are exceedingly 

 numerous. When, at the return of certain periods,! the earth 

 traverses these dense parts, great meteoric showers occur, like those 

 of the years 686, 29, 25, B. C, and those of A. D. 532, 558, 750, 

 765, 901, 935, 1095, 1096, 1122, 1799, 1803, 1832, 1833. It 

 may be supposed that in other years, the earth passes through a 

 part where the meteors are less numerous, and then only a sprink- 

 ling of meteors is seen. Whether there are more zones than one, 

 and if so, how they are situated, are problems which will proba- 

 bly long remain unsolved. Whether these meteors are the frag- 

 ments of the supposed exploded planet, of which the four asteroids 

 may have formed a part, J or whether they were originally indepen- 

 dent bodies, will perhaps be determined at a much later day. These 



* This opinion is far from being new. It is found in substance in Plutarch's 

 Life of Lysander, and although it has never been very generally received, yet it 

 has always had some supporters. It was ably illustrated and defended by the cel- 

 ebrated Chladni; and it is maintained by many at the present day. 



t The cycle of the November shower seems to be, without much doubt, 33 or 34 

 years: that of the April shower is perhaps about 27 years. 



X This hypothesis, advanced by Prof Wildt, is quoted with a partial approval 

 by the distinguished Olbers, in a valuable paper on shooting stars in Schumacher's 

 Jahrbuch for 1837. It is remarkable, that a very similar idea is found in De Mez- 

 eray's Hist, de France, (4to, Amst. 1755, tom. ii, p. 156.) in an account of the mete- 

 oric shower of 1096; his words are, " On vit durant plusieurs nuits pleuvoir des 

 Etoiles, par intervales, mais si dru et menu, qu'on eut dit que c' etoient des hluettes 

 du dihris des orhes celestes." 



