360 Phenomena attending the Fall of Meteorites on the Earth. 



than that caused by the sudden collapse of the vacuum within a 

 large fireball. 



I have left unnoticed many other particulars concerning this 

 class of phenomena, as well as attempts at explanations, and 

 the views of others respecting them ; and I even abstain from 

 mentioning their connexion with M. Coulvier-Gravier's long- 

 continued and accurate investigations. Meantime I have received 

 through the editor's particular kindness, a copy of Dr. Laurence 

 Smith's paper on the late fall of stones at New Concord, before 

 referred to in this paper, and published in Prof. Silliman's 

 American Journal (Jan. 1861, vol. xxxi. p. 87). In a letter 

 addressed to me, Dr. Smith, for a long time a most careful in- 

 vestigator of meteorites, writes as follows : — " The method 

 hitherto used in studying meteorites is still very deficient. To 

 obtain tolerably accurate notions concerning their nature and 

 origin, it would be necessary to submit to stricter criticism than 

 is generally done the phenomena attending their fall, together 

 with their physical properties, mineralogical as well as chemical. 

 We have no right to speak of the explosion of large bodies within 

 our atmosphere, while the so-called fragments of them show no 

 marks of any explosion; nor should we speak of superficial 

 heating to fusion in our atmosphere, while masses of 50 lbs. 

 weight were found, ten minutes after their fall, not warmer than 

 any stone exposed to the sun's rays, while others fell on dry 

 leaves without leaving on them any traces of combustion or 

 heating. So I could point out several other erroneous views 

 relative to the fall of meteorites, and fully refuted by the che- 

 mical and physical facts proved by the stones themselves, and 

 about which my account of the Ohio fall in Silliman's Journal 

 is to give some hints." 



I have overcome, I believe, this difficulty by placing in the 

 first period, viz. that of cosmical motion within the atmosphere, 

 the formation of the crust by superficial fusion, and in the 

 second period (that of telluric motion, or simple falling to the 

 earth) the compensation between the internal and external tem- 

 peratures. At all events, I may feel satisfied to see my own 

 views to some extent corroborated by the independent assent of 

 such a distinguished and competent observer as Prof. Laurence 

 Smith. 



Particles separated from the surface of meteorites, appearing 

 perhaps to observers in the shape of sparks, may again be covered 

 with a thinner crust, and belong to a later but still cosmical 

 portion of the orbit, as B C (fig. 2). 



It would be desirable to ascertain in new cases, and as far as 

 possible in those of older date, what is the direction of the line 

 C D with respect to the diurnal movement (west to east) of the 



