APPEARANCES OP AEROLITES. 



These meteors manifest themselves in various ways. Their 

 fall is often preceded by the appearance of a stream of light 

 passing with great velocity across a part of the firmament 

 more or less extensive, which terminates with an explosion, 

 sometimes so loud, that windows and doors, and even buildings 

 themselves, are shaken by it as if by an earthquake. This 

 phenomenon is sometimes called ball-lightning, a term which 

 is liable to the objection that it implies an analogy, or 

 identity of origin, between these meteors and common 

 lightning, which not only is not proved, but is attended with 

 no probability. 



Sometimes a small and dark cloud is observed to be suddenly 

 formed in a perfectly clear sky, which explodes with a noise 

 resembling a succession of discharges of artillery, and stones 

 are hurled from it in a shower. Such a cloud moving over an 

 extensive tract of country has sometimes thrown- down thousands 

 of meteoric stones of various, magnitudes, but alike in their 

 constituents and external appearance. 



The luminous appearance and subsequent explosion attending 

 these meteors were long known ; the fact, however, that heavy 

 substances, now called meteoric stones, were projected upon the 

 surface of the earth at the same time, was not- clearly proved or 

 generally admitted until the present century. Abundant evi- 

 dence, however, has been supplied, by the vigilance and zeal of 

 contemporaneous philosophers, of the reality of these deposits. 

 Chladni, in his work on this subject, has given an extensive 

 chronological catalogue of the meteoric stones, which supplies 

 examples of these phenomena occurring in various parts of the 

 world several times in each year of the last century. 



3. Remarkable falls of aerolites were observed at Barbotan, 

 in the department of the Landes, in France, on the 24th July, 

 1790 ; at Sienna, in Italy, on the 16th June, 1794 ; at Weston, 

 in Connecticut, U. S., on the 14th December, 1807 ; and at 

 Juvenas, in the department of Ardche, in France, on the 

 loth June, 1821. 



The phenomenon sometimes occurs under a perfectly clear 

 and unclouded sky. On the 16th September, 1843, a large 

 aerolite fell at Kleinwenden, near Mulhausen, attended with 

 a thundering noise, the sky being at the time entirely free 

 from clouds. 



The fact, then, may be regarded as conclusively established, 

 that masses of stony matter, of various magnitudes, and often of 

 very considerable weight, are frequently seen passing athwart 

 the heavens, with great apparent velocity, which are afterwards 

 precipitated upon the earth with extraordinary force. 



K 2 131 



