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the line of this chain amount to 40,000 or 50,000 feet, and 

 bear evidence of having been made in shallow water. This 

 vast accumulation could only have taken place by the sub- 

 sidence of the ocean bed along the line, thus keeping the 

 surface under water. The aggregate deposits are here much 

 greater than the highest elevation of the range, and must 

 have accumulated during subsidence. 



Prof. Hall claimed also that this same theory would apply 

 to other mountain chains, and would thus afford a natural 

 and simple explanation of those phenomena for tjie solution 

 of which unknown and unexplained forces had been appealed 

 to as the active agents. 



Adjourned. 



April 17, 1860. 



Under proposition of members, Mr. Averill proposed Dr. 

 M. L. Mead as a resident member, and Dr. Hough proposed 

 E. B. Eliott as a corresponding member. 



Prof. Hall made some remarks supplementary to and ex- 

 planatory of the communication presented by him at the 

 last meeting. He called attention to the fact that the high- 

 est of the mountains was only about one-fifth or one-sixth 

 of the whole thickness of the geological deposits from water, 

 evincing that the highest parts of the range were only more 

 abundant deposits of the same kind as were taking place on 

 each side of them. He traced the beds of sandstone from 

 their greatest thickness at the greatest altitude of the 

 range, to where they thinned out entirely at the west. 



Some discussion followed the remarks of Prof. Hall, upon 

 the principles inculcated. After which, without further 

 action, the Institute adjourned. 



May 3, 1860. 

 The president, Hon, J. V. L. Pruyn, in the chair. 



Dr. M. L. Mead, proposed at the last meeting as a resi- 

 dent member, and E. B. Eliott of Boston, proposed as a cor- 

 responding member, were duly elected. 



[Trans. w.\ 38 



