RUNNING WATERS 
167 
some heaviness of movement—but higher up 
in the hills it is all rush, vivacity, and sparkle. 
It chatters and gurgles and swishes and swirls 
all day long, working its way in and out, over 
and under bed bowlders, waterfalls, and deep 
pools. Where it runs throngh meadow or low- 
land, it keeps changing and moving its banks 
continually. Like the larger stream, the swing 
in of the water toward the shore hollows out a 
pool or deep eddy, and the sand removed from 
that bank is always deposited a few yards below 
and on the opposite bank, where a bar is form- 
ing. 
This shift of bed is not so noticeable farther 
up in the hills, where the brook runs between 
shores of rock. The change in the confining 
banks'is slight, but now there is wear of an- 
other sort. The waterfall keeps cutting back 
into the rock, the pool or basin beneath the 
fall keeps deepening, the bed along which sand 
and stones are hurried keeps sinking, and the 
vegetation year by year creeps lower down to 
cover the bare shores left by the receding water. 
The erosion of the brook tends toward deepen- 
ing the ravine and producing what is called 
the gorge or the glen. The wear here is, in 
proportion, the wear of the whole basin from 
The moun-: 
tain- 
stream. 
In the 
ravine. 
