Stored J&mtQV in Mater* 185 



was expended upon it to disengage it (whether 

 the heat was artificial or that of the sun's 

 rays) now reappears either as sensible heat or 

 as electricity, or both. And this is what is 

 meant in meteorology by latent heat becom- 

 ing sensible heat at the time of condensation ; 

 in fact, it is stored or " potential " energy be- 

 coming active or kinetic, and assumes the 

 form of heat or electricity, as before stated. 

 We have thus reviewed the matter of the fore- 

 going chapter in order to follow the course of 

 the stored energy from the melting of the ice 

 to the vapor, and back again to water: to 

 doubly impress the fact that the energy used 

 was not consumed, but still exists and is 

 ready for further work. 



During the progress of a hailstorm, it has 

 been stated, one of the factors that is active to 

 produce this phenomenon is the intense ascen- 

 sional force that is given to the moisture-laden 

 air, caused by intense heat at the surface of 

 the earth. This condition forces the moisture 

 vapor to higher regions of the atmosphere than 

 is the case with the ordinary thunderstorm. 

 Another factor that is undoubtedly active in 

 producing hail under these circumstances is 

 that when condensation takes place in the 

 higher regions, and is therefore more energetic 

 on account of the intenser cold, the potential 

 energy that is set free by the moisture 

 spherules takes, in a larger degree, the form 



