152 THE FORMS OF WATER IN 



meanings have been found for the beautiful myths and 

 stories of the Bible. 



377. It is the nature and tendency of the human 

 mind to look backward and forward ; to endeavour to 

 restore the past and predict the future. Thus endowed, 

 from data patiently and painfully won, we recover in 

 idea a state of things which existed thousands, it may 

 be millions, of years before the history of the human 

 race began. 



§ 56. The Glacial Epoch. 



378. This period of ice-extension has been named the 

 Glacial Epoch. In accounting for it great minds have 

 fallen into grave errors, as we shall presently see. 



379. The substance on which we have thus far been 

 working exists in three different states : as a solid in 

 ice; as a liquid in water; as a gas in vapour. To 

 cause it to pass from one of these states to the next 

 following one, heat is necessary. 



380. Dig a hole in the ice of the Mer de Glace in 

 summer, and place a thermometer in the hole ; it will 

 stand at 32° Fahr. Dip your thermometer into one of 

 the glacier streams ; it will still mark 32°. The ivater is 

 therefore as cold as ice. 



381. Hence the whole of the heat poured by the sun 

 upon the glacier, and which has been absorbed by the 

 glacier, is expended in simply liquefying the ice, and 

 not in rendering either ice or water a single degree 

 warmer. 



