216 cosmjs. 



teors ill 1833 (November, y|tli) the plienomenon of the 



year 1799 was called to mind.^ 



December: j\tli ; but in 1798, according to Brandes'g 



observation, December the ^th ; Herrick, in New Haven, 



1838, Dec. |th ; Hsis, 1847, December 8th and 10th. 



** Eight or nine epochs of periodic meteoric streams, of 

 wliich the last five are most certainly determined, are here 

 recommended to the industry of observers. The streams of 

 different months are not alone different from each other ; in 

 different years, also, the abundance and brilliancy of the 

 same stream varies strikingly. 



" The uiyper limits of the height of shooting stars can not 

 be ascertained with accuracy, and Olbers considers all heights 

 above 120 miles as being less certainly determined. The 

 lower boundaries which were formerly [Cosmos, vol. i., p 



* Nearer epochs of comparison might have been brought forward, if 

 they bad been known at that time ; for example, the streams of meteors 

 observed by Kloden, 1823, Nov. l|th, in Potsdam; by Berard, 1831, Nov. 

 j-|th, on the Spanish coast; and by Graf Suchtelu, at Orenberg, 1832, 

 Nov. ||th {Cosmos, vol. i., p. 124; and Schum., Astr. Nachr., No. 303 

 p. 242). The great phenomenon of the 11th and 12th of November, 

 which Bonpland and I have described {Voyage aitx Regions Equi- 

 noxiales, liv. iv., chap, x., tom. iv., p. 34, 53d ed., Svo), lasted from 

 two to four o'clock in the morning. Upon the whole journey which we 

 made through the forest region of the Orinoco southward, as far as Rio 

 Negro, we found that the enormous fall of meteors had been seen by 

 the missionaries, and in some cases recorded in the church books. In 

 Labrador and Greenland, it threw the Esquimaux into a state of utter 

 amazement as far as Lichtenaii and New Herrnhut (lat. 64^ 14'). At 

 Itterstadt, near Weimar, the pastor Zeising saw the same phenomenon 

 that was at the same time visible under the equator, and near the north 

 polar cix'cle in America. Since the periodicity of the St, Laureritrds 

 stream, August 10th, did not attract general attention until long after 

 the November period had, I have carefully placed together all the con- 

 siderable and accurately-observed falls of shooting stars on the l|th 

 November known to me up to 1846. There are 15 : 1799, 1818, 1822, 

 1823; 1831-1839, every year; 1841 and 1846. I exclude those falls 

 of meteors which ditfer by one or two days, such as those of the 10th 

 of November, 1787, 8th ofNovember, 1813. Such a periodicity close- 

 ly connected with individual days is so much the more wonderful, aa 

 bodies of such a small mass are easily exposed to disturbances, and the 

 breadth of the ring in which the meteors are supposed to be contained 

 may surround the Earth for some days. The most brilliant November 

 streams took place in 1799, 1831, 1833, 1834. (In my description of 

 the meteor of 1799, the largest fire-ball has ascribed to it a diameter 

 of 1^ and li*^, when it shou/d be 1 and 1| lunar diayneter.) This is 

 also the place to mention the fire-ball which attracted the special at- 

 tention of the director of the observatory at Toulouse, M. Petit, and 

 w hose revolution round the Earth he has calculated. {Compter Rendus 

 9 Aoat. 1847; and Schum., Asf.-. Nachr., No. 701, p. 71.) 



