THE LIGHT AND HEAT OF METEOKS. 235 



supposing the whole of the friction to be expended in heating 

 the solid mass, would raise a piece of meteoric iron 1000 C. 

 in temperature, or, in other words, to a vivid red heat. Now 

 the average velocity of the meteors seems to be thirty or forty 

 times the above amount. To compensate this, however, the 

 greater portion of the heat is, doubtless, carried away by the 

 condensed mass of air which the meteor drives before it. It 

 is known that bright meteors generally leave a luminous trail 

 behind them, which probably consists of several portions of 

 the red-hot surfaces. Meteoric masses which fall to the earth 

 often burst with a violent explosion, which may be regarded 

 as a result of the quick heating. The newly-fallen pieces 

 have been for the most part found hot, but not red-hot, which 

 is easily explainable by the circumstance, that during the 

 short time occupied by the meteor in passing through the 

 atmosphere, only a thin, superficial layer is heated to redness, 

 while but a small quantity of heat has been able to penetrate 

 to the interior of the mass. For this reason the red heat can 

 speedily disappear. 



Thus has the falling of the meteoric stone, the minute 

 remnant of processes which seems to have played an impor- 

 tant part in the formation of the heavenly bodies, conducted 

 us to the present time, where we pass from the darkness of 

 hypothetical views to the brightness of knowledge. In what 

 we have said, however, all that is hypothetical is the assump- 

 tion of Kant and Laplace, that the masses of our system were 

 once distributed as nebulaB in space. 



On account of the rarity of the case, we will still further 

 remark, in what close coincidence the results of science here 

 stand with the earlier legends of the human family, and the 

 forebodings of poetic fancy. The cosmogony of ancient na- 

 tions generally commences with chaos and darkness. 



Neither is the Mosaic tradition very divergent, particu- 

 larly when we remember that ftiat which Moses names heaven 

 is different from the blue dome above us, and is synonymous 



