Marsh.] 



124 



March fl, 



The comparative, as well as the absolute effects of "resistance" and 

 of "latent heat" are illustrated in the accompanying tabular statement ; 

 from which we see that at the height of 103 miles, the latent heat is suffi- 

 cient to raise the temperature of all the air met, six hundred millions 

 of degrees ; at sixty-eight miles, six hundred thousand degrees ; at fifty- 

 one miles, twenty thousand degrees ; at thirty-four miles, six hundred 



Explanation : — ^M = mass of air. v = velocity of meteor in feet, 



m = 3.43. nm = height in miles, 



w = number of grains of air in 5,280 cubic feet at level 



of the sea = 2,983,000. 

 X = heat rendered latent by each addition of 1 vol. 

 = 0.642O Fahr. 



