AEROLITES. 101 



taiice. Sir Alexander Burues likewise extols as a conse- 

 quence of the purity of the atmosphere in Bokhara, the 

 enchanting and constantly recurring spectacle of variously- 

 coloured shooting stars. 



The connection of meteoric stones with the grander phe- 

 nomenon of fire balls the former being known to be projected 

 from the latter with such force as to penetrate from ten to 

 fifteen feet into the earth has been proved, among many 

 other instances, in the falls of aerolites at Barbotan, in the 

 Department des Landes (24th July, 1790), at Siena (16th 

 June, 1794), at Weston, in Connecticut, U. S. (14th Decem- 

 ber, 1807), and at Juvenas, in the Department of Ardeche 

 (loth June, 1821). Meteoric stones are in some instances 

 thrown from dark clouds suddenly formed in a clear sky, and 

 fall with a noise resembling thunder. Whole districts have 

 thus occasionally been covered with thousands of fragmentary 

 masses, of uniform character but unequal magnitudes, that 

 have been hurled from one of these moving clouds. In 

 less frequent cases, as in that which occurred on the 16th of 

 September, 1843, at Kleinwenden, near Miihlhausen, a large, 

 aerolite fell with a thundering crash, while the sky was clear 

 and cloudless. The intimate affinity between fire balls and 

 shooting stars is further proved by the fact that fire balls, 

 from which meteoric stones have been thrown, have occa- 

 sionally been found, as at Angers, on the 9th of June, 1822, 

 having a diameter scarcely equal to that of the small fire- 

 works, called Roman candles. 



The formative power, and the nature of the physical and 

 chemical processes involved in these phenomena are questions 

 all equally shrouded in mystery, and we are as yet ignorant, 

 whether the particles composing the dense mass of meteoric 

 stones are originally, as in comets, separated from one another 

 In the form of vapour, and only condensed within the fiery 

 ball when they become luminous to our sight, or whether in 

 the case of smaller shooting stars any compact substance 

 actually falls, or, finally, whether a meteor is composed only 

 of a smoke -like dust, containing iron and nickel; whilst we 

 are wholly ignorant of what takes place within the dark cloud 

 from which a noise like thunder is often heard for many 

 minutes before the stones fall.* 



* On meteoric dust, see Arago, in the Annuaire for 1832, p. 254. I 

 fcave very recently endeavouped to show, in another work, (Asie Cen< 



