INTERPRETATION OF LAND FORMS 133 



or north-west, which in many places covered the preceding 

 formations with diluvial gravel, and carried along with it those 

 immense masses of granite, and the older rocks, which attest to 

 the present day the destruction and ruin of a former world. ' ' 



Another author remarks : 



' ' We find a mantle as it were of sand and gravel indifferently 

 covering all the solid strata, and evidently derived from some 

 convulsion which has lacerated and partly broken up those 

 strata. ..." 



The catastrophe favored by most geologists was floods 

 of water violently released "we believe," says the 

 editor, "that all geologists agree in imputing . . . the 

 diluvium to the agency of a deluge at one period or 

 another." 34 Such conclusions rested in no small way 

 upon Hayden 's well-known treatise on surficial deposits 

 (1821), 35 a volume which deserves a prominent place in 

 American geological literature. Hayden clearly dis- 

 tinguished the topographic and structural features of the 

 drift but found an adequate cause in general wide-spread 

 currents which "flowed impetuously across the whole 

 continent . . . from north east to south west." In review- 

 ing Hayden 's book Silliman remarks: 



"The general cause of these currents Mr. Hayden concludes to 

 be the deluge of Noah. While no one will object to the propriety 

 of ascribing very many, probably most of our alluvial features, 

 to that catastrophe, we conceive that neither Mr. Hayden, nor 

 any other man, is bound to prove the immediate physical cause 

 of that vindictive infliction. 



We would beg leave to suggest the following as a cause which 

 may have aided in deluging the earth, and which, were there 

 occasion, might do it again. 



The existence of enormous caverns in the bowels of the earth, 

 (so often imagined by authors,) appears to be no very extrava- 

 gant assumption. It is true it cannot be proved, but in a sphere 

 of eight thousand miles in diameter, it would appear in no way 

 extraordinary, that many cavities might exist, which collectively, 

 or even singly, might well contain much more than all our 

 oceans, seas, and other superficial waters, none of which are 

 probably more than a few miles in depth. If these cavities com- 

 municate in any manner with the oceans, and are (as if they 

 exist at all, they probably are,) filled with water, there exist, we 



