1 60 On the Meteors of 1 2th November, 1 833. 



The only remaining supposition is, that the matter of which the 

 denser parts of the cloud was composed, (the parts which were dis- 

 sipated without actual combustion) after having having been subject- 

 ed to so powerful a degree of incandescence, remained luminous 

 for a while after the combustion had ceased. This is a well known 

 consequence of the exposure of various substances to a very intense 

 light. Thus, after passing the electric spark from a large Ley den 

 jar, through fluor spar, the mineral remains luminous for several min- 

 utes. It must be considered, also, that only a very small portion of 

 light is required to render a body slightly luminous in the dark. 



So great a number of bodies, some of which it appears, were very 

 large, falling nearly through the atmosphere with so prodigious 

 a velocity, must have produced extensive derangements, in the at- 

 mospheric currents. The first effect was a westerly wind, which 

 suddenly succeeded the meteoric shower, in nearly every place where 

 the shower prevailed. (See p. 385.) A westerly wind (as appears 

 from the testimony of Sir H. Davy, already recited) commonly fol- 

 lows this phenomenon. Large volumes of air suddenly driven from 

 the upper to the lower regions of the atmosphere, must have a rela- 

 tive motion eastward, since the velocity due to their greater distance 

 from the earth, derived from the diurnal revolution, would not be 

 instantly lost on their descending to a lower level. In our latitude, 

 (41° 18') a body of air descending suddenly to the surface of the 

 earth from the height of twenty miles would have a relative velocity 

 eastward of five miles per hour. For, the cosiue of the latitude 

 being 2972 miles, and the diurnal motion 750 miles an hour, 

 2972 : 2992: : 750 : 755=the velocity at the elevation of 20 miles. 



A second consequence was, a sudden production of cold , an effect 

 which would follow of course from the descent of such large quan- 

 tities of air from the regions of perpetual frost.* A third consequence 

 would be the destruction of the equilibrium of the atmosphere, and 

 the prevalence of gales in various parts of the ocean. Nor is it al- 

 together improbable that some change of seasons should result from 

 so extensive a disturbance of the atmospheric equilibrium, and there- 

 fore that the remarkably warm weather of the northwestern parts of 

 the United States as described by Mr. Schoolcraft, may have been 



* The heat extricated by condensation might be supposed an equivalent; but this, 

 when produced by sudden compression would not heat a gaseous medium, which is 

 the worst of all conductors of caloric, but would escape by radiation. 



