256 —- SCIENCE SKETCHES. 
THE STORY OF A STRANGE LAND. 
In one strange land, 
’ And a long way from home, 
T heard a mighty rumbling, and I could n’t tell where. 
Negro Melody. 
LONG time ago — fifty thousand years ago 
perhaps, or it may have been twice fifty thou- 
sand—a strange thing took place in the heart 
of the Great Mountains. It was in the middle of 
the Pliocene epoch, — a long, dull time that seemed 
as if it would never come to an end. There was 
then on the east side of the Great Divide a deep 
rocky basin surrounded by high walls of granite 
gashed to the base by the wash of many streams. 
In this basin, we know not how, — for the records 
all are burned or buried, —the crust of the earth 
was broken, and a great outflow of melted lava 
surged up from below. This was no ordinary 
eruption, but a mighty outbreak of the earth’s 
imprisoned forces. The steady stream of lava 
filled the whole mountain basin, and ran out over 
its sides, covering all the country around so deeply 
that it has never been seen since. More than 
four thousand square miles of land lie buried 
under melted rock. No one can tell how deep 
the lava is, for no one has ever seen the bottom. 
Within its bed are great clefts whose ragged walls 
