ACTION OF RIVERS. 
20g 
and remember that our river valleys are the work of 
ages. Moreover, even without postulating any greater 
rainfall in former times, we must bear in mind that 
we are now looking at rivers which have attained or 
are approaching their equilibrium; they are com- 
paratively steady, and even aged; so that we cannot 
measure their present effect by that which they 
produced when they possessed the energy and im- 
petuosity of youth. 
From this point of view the upper part of a river 
valley is peculiarly interesting. It is a beautiful and 
instructive miniature. The water forms a sort of 
small-meshed net of tiny runnels. We can as it 
were surprise the river at its very commencement; 
we can find streamlets and valleys in every stage, a 
quartz pebble may divert a tiny stream, as a moun- 
tain does a great river; we find springs and torrents, 
river terraces and waterfalls, lakes and deltas in the 
space of a few square metres, and changes pass 
under our eyes which on a larger scale require thou- 
sands of years. 
And as we watch some tiny rivulet, swelling 
gradually into a little brook, joined by others from 
time to time, growing to a larger and larger torrent, 
then to a stream, and finally to a great river, it is 
impossible to resist the conclusion gradually forced 
Scenery of Switzerland. /. 14 
