116 CELESTIAL PH^ENOMEN A . 



play of meteors yet observed, viz., that described by Olmsted, 

 on the 12th and 13th of November, 1833. The Aurora 

 was also seen during the periodical phenomenon in 1838, at 

 Bremen, where, however, the fall of meteors was much less 

 striking than at Richmond, near London. I have noticed 

 elsewhere the remarkable observation of Admiral Wrangel( 75 ), 

 which he has repeatedly confirmed to me verbally, viz., that 

 during the appearance of the Aurora on the Siberian coast 

 of the Polar Sea, he frequently saw portions of the sky 

 not previously luminous which seemed to kindle when a 

 falling star shot across them, and continued bright for some 

 time afterwards. 



It is probable that the different streams or meteors, each 

 consisting of myriads of small cosmical bodies, intersect the 

 orbit of the Earth in the same way that Biela's comet does. 

 According to this view, we may imagine that they form a con- 

 tinuous ring, each pursuing its course in a common direction. 

 The small planets between Mars and Jupiter present, with 

 the exception of Pallas, an analogous arrangement in their 

 closely connected orbits. We cannot yet determine whether the 

 variations in the epochs at which the stream becomes visible 

 to us, and the retardations of the phsenomena, to which I long 

 ago called attention, indicate a regular progression or an 

 oscillation of the nodes (i. e. y the points of intersection of 

 the ring with the Earth's orbit) ; or whether they are to be 

 explained by the irregular grouping and very unequal 

 distances apart of these very small bodies ; and by 

 the supposition that the zone formed by them has a width 

 which the Earth requires several days to traverse. 

 The system of the satellites of Saturn shows us a group 

 of intimately connected cosmical bodies, occupying a zone 



