218 Outlines of Meteoric Astronomy. 



of Orgueil (in the south of France) fell at evening on the 14th 

 of May, 1864, from a meteor apparently as large as the full- 

 moon, which moved from east to west with a velocity of 

 fourteen miles per second, descending from a height of forty 

 to sixty miles above Nerac to fifteen or twenty miles above 

 the town of Orgueil, where it burst, and the stones were 

 scattered over several miles. They contain an unusual quan- 

 tity of carbon, sulphate of ammonia, and other salts. The 

 explosions of aerolites have been compared to those of 

 " Prince Rupert's drops," small beads of glass brought into 

 a high state of tension by sudden change of temperature at the 

 surface. On the slightest fracture, they fly into a thousand 

 pieces. This explanation is however doubtful : at least the 

 stones so described cannot be made to decrepitate in the flame 

 of the oxy-hydrogen blow-pipe. In the few instances, soon 

 to be described, where disruption has certainly occurred, this 

 took place when the heat on the surface had. subsided. In 

 ordinary cases separate fragments of meteorites cannot be 

 fitted together into a single block. 



(13.) Aerolites are invariably covered with a dark crust, not 

 thicker than an ordinary playing-card, of their own substance, 

 fused or molten into slag. This is evidently caused by the heat 

 of the fire-ball by which at first they are siirrounded. Ohladni 

 andVauquelin supposed that the dark veins in the stones of Char- 

 sonville were portions of the black crust, cementing together 

 broken pieces of the stone. Certain falls have, however, occurred 

 to prove that no slag is formed upon .meteorites after the time 

 that they are broken by concussion. The meteorites of Queng- 

 gouk (in Pegu) for example, which fell on the 27th December, 

 1857, fit so exactly to one another at the surfaces which have 

 not been crusted over, that the meteorite evidently parted 

 after the fire-ball ceased to melt the surface. These pieces 

 were discovered a mile apart. The meteorites of Butsura, 

 which fell near Goorka, in India, on the 1 2th of May, 1861, are a 

 more striking example in point. Five stones, in this case, weigh- 

 ing together more than 30 lbs., being joined together by their 

 fresh uncoated surfaces, fit so exactly into one large uniformly 

 crusted mass, that two fragments only are wanting at the 

 angles to prove that the stone was only broken in pieces when 

 the heat of the fire-ball had ceased to have any effect upon it. 

 These fragments of a meteorite were found at four different 

 places, lying two to three or even four miles distant from one 

 another. Sections of this meteorite and its model are ex- 

 hibited in the British Museum. With regard to veined stones 

 like those of Charsonville, the opinion of Berzelius is more 

 defensible that the black veins were formed in the primitive 

 rock of which these stones are native pieces. 



