161 



Periodic Meteors, or supposed J steroids : 



[Jan. 



4. The principal exhibition has at all times, and at all places, oc- 

 curred between midnight and sunrise, and the mao^mwm from three to 

 four o'clock. 



In all these particulars, the meteoric showers of 1834, 5 and 6, have 

 resembled that of 1833 ; while no person, so far as I have heard, has 

 observed the same combination of circumstances on any other occasion 

 within the same period. I have not supposed it necessary, in order to 

 establish the identity of these later meteoric showers with that of 

 1833, that they should be of the same magnitude with that. A small 

 eclipse I have considered a phenomenon of the same kind, with a large 

 one ; and, conformably to this analogy, I have regarded an eclipse of 

 the sun, first exhibiting itself as a slight indentation of the solar limb, 

 but increasing in magnitude at every recurrence, until it becomes total, 

 and afterwards, at each return, but partially covering the solar disk, 

 until the moon passes quite clear of the sun, — as affording no bad 

 illustration of what probably takes place in regard to these meteoric 

 showers. The fact, that the iVurora Borealis appears unusually fre- 

 quent and magnificent for a few successive years, and then for a long 

 time is scarcely seen at all, was proved by Mairan a hundred years 

 ago.* There is much reason to suspect a like periodical character in 

 the phenomenon in question, v/hich first arrested attention in 1831, be- 

 came more remarkable in 1332, arrived at its maximum in 1833, and 

 has since grown less and less at each annual return. Some seem to 

 suppose, that we are now warranted in expecting a similar exhibition 

 of meteors on the morning of every future anniversary ; and this, I 

 think, is not to be expected. It is perhaps more probable, that its 

 recurrence, unless in a very diminished degree, will scarcely be 

 witnessed again by the present gened-ation. The shower, however, 

 at its late return, was more striking than I had anticipated ; and it 

 must be acknowledged, to be adventurous, to enter the region of pre- 

 dication respecting the future exhibitions of a phenomenon, both 

 whose origin and whose laws we so imperfectly understand. 



Accounts of observations before us shew, that the meteoric shower 

 was seen in most of the Atlantic States, from Maine to South Carolina. 



From these accounts compared, we are led to conclude that the 

 meteoric shower increased in intensity from north to south, that of 

 South Carolina having been the most considerable of all, so far as ac- 

 counts have reached us. 



* Traite Phys. et Hist, tie TAurore Boreale. Par. M. de Mairau. Memoirs of the 

 jloyal Academy of Sciences for l7.il. 



