AEROLITES. 107 



showers of shooting stars fell in Ciimana in 1799, and in 

 North America in 1833 and 1834, shews, that balls of fire 

 and shooting stars are not only often contemporaneous and 

 intermingled, but that they pass gradually one into the 

 other, whether we compare the magnitude of their disks, or 

 the trains which accompany them, or the velocities of their 

 movement. While there are exploding and smoke-emitting 

 balls of fire, which are luminous even in the bright sunshine 

 of a tropic day( 58 ), and sometimes exceed in size the apparent 

 diameter of the Moon, there are, on the other hand, shooting 

 stars which fall in immense numbers, and are of such small 

 dimensions, that they exhibit themselves only as moving 

 points, or as phosphorescent lines ( 59 ) . Whether among the 

 many luminous bodies which shoot across the sky, there may 

 not be some of a different nature from others, still remains un- 

 certain. In the equinoctial zone, I received the impression 

 that, both on the low burm'ng plains, and at elevations of 

 twelve or fifteen thousand feet, falling stars were there more 

 frequent, of brighter colours, and more often accompanied 

 by long brilliant trains of light, than in the colder latitudes ; 

 but doubtless this impression was occasioned solely by the 

 exceeding transparency of the tropical atmosphere, which 

 enables the eye to penetrate farther into its depths ( 6o ). Sir 

 Alexander Burnes extols, as a consequence of the serenity 

 and clearness of the air and sky in Bokhara, the brilliant 

 and frequently recurring spectacle of variously coloured 

 meteors. 



The connection of meteoric stones with the more splendid 

 phsenomenon of fire-balls, and the fact that meteoric stones 

 sometimes fall from fire-balls with a force which causes them 

 to sink to a depth of from ten to fifteen feet into the earth, 



