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POPULAR SCIENCE MONTHLY. 



corresponds in position to an extension of tlie basin of the Gulf of 

 Mexico, toward whicli, from the Pacific side, there is a similar inden- 

 tation of the continental mass as shown on map, Fig. 2. The Hon- 

 duras basin, indenting the Central American plateau, has a corre- 

 sponding depression across it at an altitude of about twenty-seven 

 hundred feet. The Caribbean Sea proper has a more uniform 



Fir 



-Map of Cextkal America, showing the indentations corresponding to tlie ^Mexican, 

 Honduras, and Caribbean basins. (Soundings in feet. ) 



breadth than the other basins, and in like manner the American 

 barrier, which is here narrower than farther north, is dissected in 

 several places, as might be supposed. These depressions make it 

 a;ppear that the Caribbean basin was connected by several channels 

 across the continent with the Pacific Ocean. The Mcaragua de- 

 pression is the most northern. The elevation of the valley east of 

 Lake Nicaragua is about three hundred and fifty feet above the sea, 

 although the San Juan has further dissected it so as to reduce its 



