256 THE BEAUTIES OF NATURE chap. 



slope, shows where the water comes to the 

 surface, a treacherous covering of verdure 

 often concealing a deep pool beneath. From 

 this source the rivulet trickles along the grass 

 and heath, which it soon cuts through, reach- 

 ing the black, peaty layer below, and running 

 in it for a short way as in a gutter. Exca- 

 vating its channel in the peat, it comes down 

 to the soil, often a stony earth bleached white 

 by the peat. Deepening and widening the 

 channel as it gathers force with the increas- 

 ing slope, the water digs into the coating of 

 drift or loose decomposed rock that covers 

 the hillside. In favourable localities a nar- 

 row precipitous gully, twenty or thirty feet 

 deep, may thus be scooped out in the course 

 of a few years." 



If, however, we trace one of the Swiss 

 rivers to its source we shall generally find 

 that it begins in a snow field or neve nestled 

 in a shoulder of some great mountain. 



Below the nev^ lies a glacier, on, in, and 

 under which the water runs in a thousand 

 little streams, eventually emerging at the 

 end, in some cases forming a beautiful blue 



