302 METEORS AND AEEOLITES. 



meteors of every class, we obtain the only clear notion of a 

 cause of periodicity ; the law being the same which governs 

 the planetary system at large, and even the most excentric 

 motions depending on the great principle which maintains 

 general order throughout the universe. 



It must be admitted that this theory materially changes 

 our manner of viewing the interplanetary spaces around us. 

 No longer regarded as a void or filled solely by a subtle 

 ether, imponderable and unseen these spaces now present 

 themselves as occupied in various parts by matter apparently 

 of the same nature as those of which our globe is composed ; 

 but either not yet aggregated into planetary forms, or 

 detached from planetary bodies previously existing. If 

 adopting this idea of meteoric zones or rings, we must 

 necessarily admit at least two such in explanation of the 

 separate, but similar, phenomena of the August and November 

 showers. Many (questions, however, still remain open ; such 

 as, whether these zones are of uniform composition and 

 arrangement ? whether there is any proof of a progression 

 in the line of nodes, or of oscillation from perturbations ? 

 whether we may attribute to them the occasional obscuration 

 of the Sun for short periods, which we find on frequent 

 record ? and on what physical causes depend the luminous 

 globes and shooting-stars which emanate from them on 

 approaching the earth ? * 



Other questions there are, awaiting the possible solution of 

 the future, some of which our readers will already infer. To 

 explain the appearance of single meteors, always so sudden, 

 often so brilliant as well as the more substantial pheno- 

 menon of falling stones must we not suppose detached 

 portions of matter, equally revolving as the zones which 



* The most authentic statement as to the August zone is that of Professor 

 Twining, founded on his own diligent observation of the phenomena occurring 

 in this month. 



