INSIDE OF THE EARTH 47 



perts to tell with a good deal of certainty what to expect in 

 the way of well-water. But in the old days, when a well 

 was to be located, it was quite customary to employ a 

 "water- witch." A water-witch was a person supposed to 

 have mysterious power to locate favorable spots for wells. 

 This was done with the aid of "divining-rods." A favorite 

 form of such rod was a forked branch of hazel, or peach. 

 The rod was held by the forks, the main stem pointing 

 straight forward. Then, as the holder passed over water, 

 the main stem was supposed to twitch downward. It 

 has never been possible to prove that this is so, and it 

 seems absurd, yet there are many people to-day who 

 still believe there is "something in it." In support of 

 their belief, they point to wells which have been located 

 in that way. Does this prove anything ? Yet many things 

 which people believe to be true are founded on no better 

 evidence than this. The great work of science is to find 

 out what is true and what is false. 



The Inside of the Earth. We cannot think of under- 

 ground water in wells and springs and hidden streams 

 without thinking of the inside of the earth. Have you 

 not wondered about this mysterious region? Have you 

 not wanted to explore caves, and to see the stalactites like 

 rock icicles (see Fig. 18) whose pictures you have seen in 

 geographies? Scientists, too, have done a good deal of 

 wondering about the inside of the earth, but they have not 

 found out very much. The deepest mines are but mere 

 scratchings when you think of all that is beneath them. 

 It is more than eight thousand miles through to China, 

 and the deepest borings of man go down only a few thousand 

 feet. And yet these borings, and other things, have given 



