114 ON EROSIONS OP THE EARTH'S SURFACE. 



the sensations of intense pleasure I experienced, as I gazed on these grand and 

 novel displays of nature." — See also Capt. Marcy's Report, p. 55, et seq. 



12. Hot Spring Gate, on the River Platte, in about 107° W. longitude. — The river 

 here passes through a hill of white calcareous sandstone, a distance of about 1200 

 feet, with a depth of about 360 feet. At both extremities is a smooth green 

 prairie. Col. J. C. Fremont has named, described, and given a sketch of this 

 gorge in his first Report, p. 55. 



13. Rapids in St. Louis River, west of Lake Superior, towards the Portage aux 

 Coteaux. — The gorge is 36 miles long at least, and the walls from 30 to 40 feet 

 high, in argillaceous slate. In that distance are four distinct falls, each made up 

 of several distinct cascades. Here doubtless the work of erosion and retrocession 

 is going on at every cascade. — Owen's Report on Wisconsin and Iowa, in 1848, 

 p. 79. 



14. Canon in the Rocky Mountains, on one of the branches of Snalce or Leiois 

 River. — The distance through it occupied a half day's travel, the walls are very 

 precipitous and high, and the rocks are sandstone, limestone, and gypsum. — ■ 

 Parker's Exploration, 3d edition, p. 87. 



15. Gulfs of Loraine and Redmond, in Jefferson county, New York. — These appear 

 to be genuine canons upon the small streams flowing through the Trenton lime- 

 stone, Utica slate, and Loraine shales of those towns. Those are the most striking 

 upon South Sandy creek. The walls are perpendicular, and vary in height from 

 100 to 300 feet. The width of the gulf varies of course, and is sometimes as 

 much as sixteen rods. The length of some of them is over twelve miles, reaching 

 to the very starting-point of the streams. — Emmons Report on the Second Geological 

 District of New York, p. 408. 



16. Gorge on Cox River, in Neio South Wcdes, in Australia. — This is 2200 yards 

 wide and 800 feet deep, cut in horizontally stratified sandstone. From this valley 

 Major Mitchell estimates that 134 cubic miles of stone have been removed. — Am. 

 Journal Science, vol. IX., New Series, p. 290. 



17. Kangaroo Valley is another example of erosion in the same country. It is 

 two or three miles wide, and from 1000 to 1800 feet deep, opening outward through 

 a comparatively narrow gorge. Professor Dana estimates the amount of rock 

 necessary to fill the valley, and which has been removed, to be equal to " a rect- 

 angular ridge 12 miles long, two miles wide, and 2000 feet high." 



The above are only two out of a multitude of valleys in New South Wales, 

 which have been excavated in horizontal strata of sandstone. They are usually 

 narrowest and deepest towards the sea, resembling a harbor with a narrow entrance. 

 Professor Dana has shown in a conclusive manner, that these valleys are the work 

 of running water, and not of convulsions or of original creation. — Am. Journal of 

 Science, vol. IX., New Series, p. 289. 



18. Gorge of the Rhine, between Coblentz and Bingen. — All that distance, nearly 

 50 miles, the river has cut across ranges of mountains of the older fossiliferous 

 rocks, to a depth sometimes as great as 1000 feet. The gulf is a true mountain 

 gorge, and the banks are so precipitous as scai'cely to afford room for a narrow 

 terrace. The idea that the waves of the ocean, or a rent by internal forces, pro- 



