EARTH PULSATIONS. 339 



originators of vast pulsations whicli may be recorded on 

 the surface of the earth as wave-like motions of slow 

 period. 



As an explanation of the strange movements observed 

 on seas and lakes, Kluge brings forward the following 

 strange and remarkable theory. The oxygen of the air is 

 magnetic, whilst water is diamagnetic and the earth mag- 

 netic: we have, therefore, in our seas and lakes a dia- 

 magnetic body lying between and being, consequently, 

 repelled from two magnetic bodies. By variation in tem- 

 perature, the balance of repulsions exerted by the air and 

 the earth is destroyed. Thus, by an elevation of tem- 

 perature the air expands and flows away from the heated 

 area, where, in consequence, there is less oxygen. The 

 result of this is, that the repulsion of the air upon the 

 waters is less than that of the earth upon the waters, and 

 the waters are in consequence raised up. By a falling of 

 temperature the waters may be depressed, and by either 

 of these actions waves may be produced without the in- 

 tervention of earthquakes or earth pulsations. 



The more definite kinds of information which we have 

 to bring forward, tending to prove the existence of earth 

 pulsations, too slow in period to be experienced by ordin- 

 ary observers, are those which appear to be resultant 

 phenomena of great earthquakes. 



The phenomena that we are certain of in connection 

 with earth vibrations, whether these vibrations are pro- 

 duced artificially by explosions of dynamite in bore-holes, 

 or whether they are produced naturally by earthquakes, 

 are, first, that a disturbance as it dies out at a given 

 point often shows in the diagrams obtained by seismo- 

 graphs a decrease in period; and, secondly, a similar 

 decrease in the period of the disturbance takes place as 

 the disturbance spreads. 



