THE FALLS OF THE MISSISSIPPI. 477 



and so continued until the limestone again appeared in its natural 

 position. 



There are no rock-bluffs below the confluence of the Ohio with the 

 Mississippi, but about thirty miles above that point they abruptly rise 

 on both sides of the river at what is called the Grand Chain, a high 

 rock ridge traversing the region from east to west, and which lies at a 

 considerable height above the sea-level. There, in all probability, the 

 river had its original outlet, and there, without doubt, the cataract 

 process began, although the character of the stratification is unknown 

 to us. At the time the erosion was in progress, there must have been 

 several times the present volume of water flowing in the river, spread- 

 ing out wider than the bluff, even, as an occasional terrace shows. 

 The same perpendicular rock-walls and sand-bottom characterize the 

 Wisconsin River for a distance of eighty miles from its junction with 

 the Mississippi ; the position and character of the stratification being 

 much the same, indicating that the same agency was active in the 

 erosion of both channels. 



St. Anthony Falls have been studied by Professor Winchell, and 

 he has arrived at the conclusion from various data that the falls have 

 worked their way back from a point near Fort Snelling to where they 

 now are, a distance of about eight miles, since the glacial period, and 

 he estimates that it has taken about five thousand years to accomplish 

 the work, which estimate, taken as a basis of calculation, and allowing 

 a margin of at least one third, gives us the time necessary to cut out 

 the entire channel at, say, four hundred thousand years ; and this, if, 

 as we maintain, the cataract process wrought the gorge not only from 

 Fort Snelling northward, but from far down the river, at or near the 

 ancient outlet, is without doubt a conservative estimate of the time 

 actually required. 



We have thus briefly outlined the new theory of the Mississippi ero- 

 sion, and this is written with the expectation that the barbed arrows of 

 scientific criticism will be aimed toward it ; but, if so, it will aid in the 

 solution of a question hitherto little studied. Many things point toward 

 the theory here advanced as being at least quite possible, and even 

 probable. Its final solution will, however, necessitate painstaking in- 

 vestigation, with the attention directed to that especial object. 



Madame Clemenoe Rotek, writing in the " Revue d'Anthropologie," does 

 not doubt that, under a proper system of training, apes might be made good 

 workers. They lack perseverance, indeed, but in general intelligence they are 

 superior to most other domestic animals. They would, however, have to be fed 

 great quantities of fruit, bread, and eggs ; the process of educating them would 

 be costly ; and for many generations they would be injuriously affected by north- 

 ern climates. Madame Royer suggests that, if the experiment be made, it be first 

 in tropical climates, where apes might be taught to labor in connection with the 

 cultivation of coffee, cocoa, and cotton. 



