THE GREAT LINES OF CLIFFS. 69 



pressed down in a certain direction, will each and all 

 afford unerring proofs of the previous passage of some 

 man or animal and he will tell you to a nicety, by 

 means which it would be too intricate to attempt to explain 

 here, exactly what it was that made the mark : 

 how long ago, at what speed, and for what purpose, 

 it had passed. 



But to him the beetling cliffs above convey no 

 meaning no lesson. Yet, as Professor Powell is care- 

 ful to point out " perhaps the most wonderful of the 

 topographical features of the country are these lines 

 of cliffs, escarpments of rock, separating upper from 

 lower regions, often vertical and impassable barriers, 

 hundreds or thousands of feet high ; and scores, or 

 hundreds of miles in length. " * 



Everything upon the American continent seems to 

 be formed upon so vast a scale that it is not always 

 easy for the average stay-at-home Briton to realize 

 upon a small scale, what these great natural barriers 

 are like; if however we might venture to suggest an 

 example, we would refer the British enquirer to an 

 inspection of the Undercliff in the Isle of Wight and 

 for two reasons, first because it gives a picture in 

 miniature of the great cliffs of the American plains 

 region, and secondly because the means by which 

 they were created are to some extent apparent. 



To what great natural force shall we ascribe them ? 

 Were they upheaved from the bowels of the earth 

 beneath? or did some great subsidence of the plain 

 below leave them standing aloft as an eternal memorial 

 of some vast terrestial movement of former ages? 



* Report to the United States House of Representatives on the Survey 

 of the Colorado River of the West, by Professor J. W. Powell, 1874, p. 9. 



