192 THE SEVEN FOLLIES OF SCIENCE 



3. The gradual cooling of the earth and the consequent 

 contraction of the crust, which would proceed more rapidly 

 and to a greater extent than the contraction of the liquid 

 interior. That the earth is gradually cooling is a fact 

 which is generally accepted by scientific men. In other 

 words, the earth radiates into space an amount of heat 

 greater than that which it receives from the sun and stars. 

 Consequently the crust becomes too small to contain the 

 liquid contents of the globe and a portion of the latter is 

 ejected at the point of least resistance, which may be 

 either an old vent or a new opening. Cordier has calculated 

 that a contraction of only the one-twenty-fifth of an inch 

 would suffice to force out to the surface lava enough for 

 500 eruptions, allowing 1300 million cubic yards for each 

 eruption. This cooling process is, however, very slow, 

 so slow that it may not have been recognizable during the 

 historic period. But we must remember that an amount 

 which would be quite imperceptible by our most delicate 

 instruments would be sufficient to produce all the volcanic 

 phenomena with which we are familiar. 



THAT THE FORCE OF DYNAMITE IS ALWAYS 

 EXERTED IN A DOWNWARD DIRECTION 



is a well-known fact that if a charge of dyna- 

 mite be laid on the ground and exploded, it 

 will make a deep hollow, and if it be placed on 

 a slab of stone, even without any covering or 

 tamping, as it is called, the stone will be broken into 

 shivers. It was these facts that led to the belief that 

 dynamite acted only in a downward direction, and as there 



