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PROCEEDINGS OF THE CALIFORNIA 



A specimen of fossil wood, petrified by carbonate of iron, found 

 in the ]Mount Diablo coal mines, was exhibited by Mr. Durand from 

 the cabinet of Mr. Pioche. 



Judge Hastings read a brief paper on earthquakes, propounding 

 the theory that they are caused by the falling in of the walls of 

 caverns beneath the crust of the earth. He thought subterranean 

 water action might be an agent of these collapses. He believed 

 that the cessation of earthquakes in countries once disturbed by 

 them, like England, was due to the final settling in of the earth's 

 crust and filling up of cavernous vortices. He asserted that earth- 

 quakes are confined to countries where long dry seasons prevail, 

 and that the phenomena recur at the period between the dry and 

 rainy seasons, as in California, where they are most marked in the 

 Fall and Spring. In allusion to the subterranean Avater sources, he 

 explained the increase in the volume of springs and streams at the 



