282 



PHYSICAL GEOGRAPHY. 



motion long after its bed has lost all inclination. The chief effect of the absence of a 

 declivity is a slower movement of the stream, and a more winding course, owing to the 



aqueous particles being more susceptible of 

 divergence from their original direction by 

 .-'-'." _,, impediments in their path. Hence the tortuous 

 character of the water-courses, chiefly arising 

 from the streams meeting with levels after 



The Rhine at Obcrweisel. 



descending inclined planes, which so slackens their speed that they are easily diverted 

 from a ri^ht-onward direction by natural obstacles, to which the force of their current is 

 inferior. The Mseander was famed in classical antiquity for its mazy course, descending 

 from the pastures of Phrygia, with many involutions, into the vine-clad province of the 

 Carians, which it divided from Lydia near a plain properly called the Maeandrian, where 

 the bed was winding in a remarkable degree. From the name of this river we have 

 our word meandering, as applied to erratic streams. 



This circumstance increases prodigiously the extent of their channels, and renders 

 their navigation tedious, but the absence of that velocity of the current which would make 

 it difficult is a compensation, while a larger portion of the earth enjoys the benefit of 

 their waters. The sources of the Mississippi are only 1250 miles from its mouth, follow 

 ing a straight line, but 3200 miles, pursuing its real path ; and the Forth is actually 

 three times the length of a straight line drawn from its rise to its termination. The 

 rivers which flow through flat alluvial plains frequently exhibit great sinuosities, their 

 waters returning nearly to the same point, after an extensive tour. The Moselle, after a 

 curved course of seventeen miles, returns to within a few hundred yards of the same spot ; 

 and a steamer on the Mississippi, after a sail of twenty-five or thirty miles, is brought 

 round again, almost within hail of the place where it was two or three hours before. In 

 high floods, the waters frequently force a passage through the isthmuses which are thus 

 formed, converting the peninsulas into islands, and forming a nearer route for the 

 navigator to pursue. By the "grand cut off" on the Mississippi, vessels now pass from 

 one point to another in half a mile, in order to accomplish which they had formerly a 

 distance of twenty miles to traverse. 



Rivers receive a peculiar impress from the geological character of the districts through 



