260 SCIENCE SKETCHES. 
lingers on the highest peaks that surround the 
lava-beds. 
Then the winters grew shorter and the summers 
longer. The south winds blew, and the ice melted 
away, first from the plain and then from the moun- 
tains. The water ran down the sides of the lava-bed, 
cutting deep gorges or cafions, so deep that the sun 
can hardly see the bottom. And into the joints 
and clefts of the rocks more and more water went, 
to be hurled back with greater and greater violence, 
for all the waters of all the snow cannot put out 
a mile deep of fire. 
In the old depressions where the ice had chiselled 
away the softer rocks, there were formed lakes of 
the standing water, and one of these was more 
than thirty miles long, winding in and out among 
the mountain-ridges. In the lake bottom the water 
soaked through down to the hot lava below, from 
which it was thrown boiling back to the surface 
again, fountains of scalding water in the icy lake. 
The cold Ice age had killed all the plants in the 
region; it had driven off the animals that could 
be driven, and had then buried the rest. But 
when the snow was gone the creatures all came 
back again. Grass and meadow-flowers of a 
hundred kinds came up from the valleys below. 
The willow and the aspen took their place again 
by the brookside, and the red fir and the mountain 
pine covered the hills with their sombre green. 
The birds came back. The wild goose swam and 
screamed, and the winter wren carolled his bright 
song, — loudest when there seemed least cause for 
rejoicing. The beaver cut his timber and patiently 
