220 ObiervaitQfis on the Fall of Stones 



give such an extent to the meteor ; for then the meteor nuist be 

 composed of the metnliic mrxss, and of the vapours which it 

 drags with it; whereas the form of this metallic mass is always 

 more or let^s round and circumscribed. It must, therefore, be 

 sup)x>sed that the greater part of tliese globes is not composed 

 of metallic parts solely, while they pass through the air, but of 

 inflammable parts which are consiuned during the rapid course 

 of those globes. 



This seems also proved by tlie luminous phenomena which 

 accompany these mcleors, for thcv are not the same with those 

 produced by incandL.>-Lvnt metii'iic bodies. The colour of the 

 flame is, in fact, v/hite, like that of camphor or phosphorus in a 

 state of ignition, in the aerolites of Connecticut or Weston in 

 America, which fell in 180'/, the light precisely followed the path 

 of the eruptions ; it was extinguiohed with every eruption, to re- 

 appear with the one succeeding. If, as some observers have 

 asserted, the light was the consequence of the incandescent state 

 of the aerolite occasioned by the rapidity of its fall, then t!his 

 state of incandescence must increase with the time occupied by 

 the fall : but the case is almost always different, and several stones 

 observed in the air are extinguished before reaching the ground. 

 The form of these meteors, besides, agrees wnth this opinion; for 

 it is not always the sanxe : thus, the stone which fell in England 

 on the 18th of August 1783 sometimes affected a round form, 

 and sometimes an elongated one. The remarkable effervescence 

 which has even been observed in several of these aerolites, seems 

 also to prove that there is no question in the case either of a 

 metallic consistence, or of simple vapours which surround the 

 nucleus, because the edges are always very distinct, and are not 

 insensibly lost. In short, if, in spite of all appearances, the 

 greater part of this description of meteors is to be ascribed to 

 vapours, we should nevertheless be puzzled to account for their 

 origin, since aerolites are almost uniformly composed of earthv 

 and metallic parts, which can scarcely be vaporized at the tem- 

 perature of our atmosphere. 



A parabolic orbit is generally assigned to aerolites, but the 

 angle formed by the parabola with the horizon is not always the 

 same. In fact, tliere fell in France in 1 783, a stone which formed 

 an almost horizontal hole, and that of Stannern made a cavity of 

 two feet diameter and two inches in depth only. Other stones, 

 like that which fell in 1810 at Orleans, or that which was ob- 

 served in Calabria in the year 175"), constantly preserved in 

 their fall a direction almost perpendicular. These facts seem to 

 indicate, that besides gravity there must also be another force, 

 which opposed to the direction given bv the weight may modify 

 their orbit. We have a new proof of this in the aerolite of 



Connecticut, 



