260 Review of tJie Glacial Theory. 



nels of these rivers could have been cut out, without any elevation of 

 the continent. Without spi-eading over too much country, let us look 

 at the trough of the Ohio Eiver. It seems to have been worn out, be- 

 tween the time of the elevation of the Allegheny Mountains and the 

 advent of the drift, to a depth of 100 feet or more, below the bed of 

 the present river. The bottom of that trough is, at this place, about 

 300 feet above the level of the ocean, and according to probable es- 

 timates, the river will again clear out that trough and excavate it 

 deeper, in much less time than elapsed, between the elevation of the 

 Allegheny range and the deposit of the drift. Indeed, the fall of the 

 Ohio River, is such, that in the course of time, it may excavate its trough 

 more than 300 feet below its present bed. Whatever is true of the 

 Ohio River in this regard, is alike true of the Mississippi and of all 

 its northern tributaries. The same rule will apply to every stream 

 that flows from the continent to the ocean. The bed of no trough, 

 where a river now flows, or where a stream has run since the Tertiary 

 period, Avithin my knowledge, is lower than the ocean level, and Pro- 

 fessor Newberry, unfortunately for his theory, has not attempted to 

 refer to any such. In short, the excavation of the river channels of 

 this continent do not indicate that the continent was ever higher than 

 it is novv. 



But what power could lift the continent several hundred feet higher 

 than it is now, and let it down again, without disturbing the course of 

 the rivers and upturning the geological formations ? Those who see 

 nothing but cataclysms in the past history of the earth, and are ready 

 to believe, if they can find it in print, that a rain storm covered the 

 earth fifteen cubits deep, on the highest mountains, and that a man 

 collected together the trilobites, cephalopods and whales, and fed them 

 on salt water until the storm was over, so that not one of them per- 

 ished, are prepared, no doubt, to believe that the continent was 

 elevated several hundred feet higher than it is now, since the close of 

 the Tertiary period, and that after it was supported up there for a long 

 time, it was gradually lowered again to its present position, without 

 disturbing the general geological character of the surface, merely be- 

 cause they find it so written in a book. Such extravagant suppositions 

 do not constitute any part of science, nor can I see that they are 

 worthy of being considered part of any geological theory. It has 

 been the province of geology to show, that the economy of nature, in 

 the formation of the earth's surface, is the same now, that it has been 

 for millions of years — even back through the Tertiary and Cretaceous 

 ages — yea, even back through Silurian and Eozoic time. No geologist 

 can confidently point to a period, in the earth's history, when there 



