20 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



large portions of the celestial spaces are probably occupied 

 by small particles of matter, forming cosmical clouds, whose 

 motions may be similar to those of the stars. He then show- 

 ed that if such a cloud were to come within the attractive 

 influence of the sun, under favorable circumstances, it would 

 become a permanent member of the solar system, and would 

 gradually be drawn into the form of a cylinder, which would 

 continually lengthen till its two ends should meet, and it 

 would be thus converted into a stream of particles flowing 

 around the sun in an ellij)tical orbit. There are many of 

 these streams in the solar system, but the particles compos- 

 ing them are so widely separated that their orbits may cross 

 each other without interruption. When the earth encounters 

 one of these streams, such of the particles as happen to pass 

 through our atmosphere take tire from the friction generated 

 by their own motion, and become visible as meteors, or fall- 

 ing stars, for such, in truth, they are, as they come from the 

 stellar regions. They have the same relations to comets that 

 asteroids have to planets ; in both cases their small size is 

 compensated for by their greater number. 



It is almost certain that falling stars, meteors, and aerolites 

 differ in size only, and not in composition. Hence we pre- 

 sume that they are an example of the materials of the uni- 

 verse; and as they contain no elements foreign to those of 

 the earth, we may infer the similarity of composition in the 

 whole universe a fact already suggested by the revelations 

 of the spectroscope. 



Finally, to put beyond all question the intimate relation 

 existing between comets and meteorites, Signor Schiaparelli 

 has discovered that the orbit of the August meteors is iden- 

 tical with that of comet II., 1862, and that the orbit of the 

 November meteors is identical with that of comet I., 1866, 

 thus rendering it very probable that these comets were only 

 highly condensed portions of the meteoric rings. Signor Schi- 

 aparelli concludes his last memoir with the following remark- 

 able words: "Must we regard these falling stars as swarms 

 of small comets, or rather as the product of the dissolution 

 of so many great comets? I dare make no reply to such a 

 question." Monthly Notices B. Astron. Soc, 1,1872, XXXIL, 

 194. 



