444 



Parabolic Law of Rivers. 



of the earth is eroded, and how enormously increase of quantity of water or 

 ice increased denudation or erosion of the land. 



I can prove that motion is in proportion to slope of channel and the quantity 

 of water flowing, jointly, by the result of experiment. My diagrams, also, 

 are correct representations of the forms and contours of cliffs and valleys 

 actually caused by the action of rain and spring. water, rendering beds of sand 

 and rock unstable on a surface bed of clay. The actual slip that has occurred 

 is the measure of the instability, and is dependent upon the angle, the weight, 

 and the lubrication by water of the surfaces sliding on each other. 



(n) For large rivers I take the Rhine (Fig. 5) ; but as the most remarkable 

 rivers are in Asia, Africa, and America, I ought to allude to those countries, 



rg;5. 



Hf/t//>t above the Level of t/ie Sea at B 273-2 ?~ 



RHINE. 



Do 



Lcngrtk B 



Flood water levels from 



I on Nohl inq~ . 



do, at S 



2SJ&mdes 4m=0l283. 



! 



i! 1 



DATUM LIME ~ <^,~ * 



Flood level of MAine compared withParaoola; u/itA. 

 horizontal axis of lAeJbrmala tJ a = 4<MX q^ylor.del^ 



FIG. 5'. RM'NE 

 <- —71 cere! Sirahe- ■■■> 4~ Soft 



Strcdcc > 



mm 



renct 



^(^i or? 1 •^Siv0' s *3: ^-'i "-'[ S" v 'Ji 



\M£asiwiLw.ui? cftpoiiitv \2J1r.rc Gifvetf 

 ! Burr ik nni/ioai the Pcaicd oZa. ; 



^teasarfJp.eiit <fLo \ ! do 

 z'i Taitllin iJie ■ ■Puru&dfci. \ 



fq 



s^S, 



Ki 



<3 



I 



Fig. 5- The Rhine show; that rivers flow, where navigable, in a curved 

 basin. The hard rock raises the water level, the soft lowers it. Fig. 5 is a 

 type of all other navigable rivers, 4m = 0*1235 f eet nl rne Rhine, and o - o6i79 

 feet in the Mississippi. All rivers approaching to Fig. 5 where navigable. 



One great difficulty of my subject is, no doubt, the existence of large lakes 

 such as we see in Snowdonia, and still larger in Switzerland. Now I believe 

 that rivers could at no time form lakes, for the action and function of our 

 present rivers is to fill up all hollows and produce a channel of such a form 

 and slope that the water approaches to uniform motion from adjusting the 



