A RAINY DAY. 209 



however, to find that, on a miniature scale, the 

 rain-rills in the road are doing their best to emulate 

 the work of their greater neighbours of the valleys 

 and the plains. 



You have seen how the rills of the road cut out 

 their channels through the interstices of the stones, 

 and shape their course according to the obstacles they 

 encounter in their journeys to the gutter. Each rill 

 is like your winding river. With a spice of philo- 

 sophy, it goes round what it cannot sweep away. 

 This is the case with many a stream you know which 

 meanders through flat-lands, without the flood and 

 force necessary to carve out a straight course and to 

 sweep all before it. The Thames in its flat-lands, or 

 the "sweet winding Devon" of the north, whereof 

 Burns sings, illustrate rivers which flow in a sinuous 

 course because they have not the force necessary to 

 sweep away the obstacles which oppose them. But 

 when you read of the doings of such a river as the 

 Rio Colorado of the West, your respect for the work 

 of running water increases vastly in extent. The 

 Colorado river, in part of its course, runs through 

 rocky defiles, or " canons," of immense depth. These 

 canons measure in some parts more than a mile in 

 depth, and extend for many miles as the natural course 

 of the river. Now, it is provable that the river itself 

 has actually made these canons. It has slowly, but 

 surely, through the long ages, cut and carved its way 

 downwards through the rock, until it has found a 

 channel a mile deep from the surface. Geologists 

 will tell you that this river has been a successful 

 sculptor of the earth, because its waters carry just a 

 sufficiency of sand to eat out, as does a file, the hard 

 substance of the rocks. This is river-action on a 



