THE ROMANCE OF A RIVER 



165 



thus made of service all through the 

 seasons. 



Let us imagine three rivers. H. R, and 

 C, beginning their careers on a slope of 

 land which has just emerged from the 

 sea. As yet the ground has not been 



HOW THE RIBBLE BEGGARED ITS 

 NEIGHBOURS-I. 



scored by frost or rains, but presents a 

 smooth, even surface. Gradually the 

 forces gnawing at the rocks discover lines 

 of weakness, and the waters begin to run 

 in defined courses (Fig. i). Tributaries 

 are formed which flow into the main 

 streams, and still the three young rivers, 



/^— --p\ 



HOW THE RIBBLE BEGGARED ITS 

 NEIGHBOURS II. 



pursuing independent paths, enter the 

 sea by different mouths (Fig. 11.). Now 

 let us suppose that one of the rivers — R, 

 for example — possesses some advantage 



over H and C. It cuts a deeper channel. 

 This gives the tributaries a steeper fall, 

 and they cut back more effectively than 

 those of H and C. Finally, one of the 

 tributaries of R succeeds in reaching the 

 main stream of H, whose head waters 

 are captured and diverted along the tri- 

 butary to join R. Similarly a tributary on 

 the left bank captures the head waters 

 of C, and the valleys cut out by H and C 

 below the point of capture are left stream- 

 less, or only a mere trickle is formed by 



THE RIBBLE AS IT IS TO-DAY-IIL 



the scanty drainage from the slopes on 

 either side (Fig. in.). The last diagram is 

 copied from a map of North Lancashire, 

 and gives the present courses of three 

 rivers — the Hodder, the Ribble. and the 

 Lancashire Calder.* Standing at the elbow 

 of capture of the Hodder, and looking sea- 

 wards, we have a broad valley in front 

 of us through which a tiny stream flows. 

 It does not fit the valley, but meanders 

 in tiny curves inside a valley with swings 

 which correspond to a much larger river. 

 Similarly from the elbow of capture of 

 the Calder we have an open valley towards 

 the sea practically streamlcss. 



* The coast-liiio givrii in the diapram does not 

 follow the present outline of the shore. Changes 

 have taken place since the events described above 

 happened. 



