ver. They match as perfectly as the grain of
a block of wood when sawn asunder--showing that these coal beds were
formed at an age long before the water cut this sinuous groove. What the
water was doing while these coal beds were forming will be brought out
in some future chapter. All the rivers that are tributary to the Ohio,
such as the Monongahela, the Alleghany, the Muskingum, the Tennessee,
the Cumberland, the Kentucky, the Wabash, the Miami, the Licking, the
Scioto, the Big Sandy, the Kanawha, the Hocking, and the Great Beaver,
besides numerous smaller streams, have their own valleys that have been
worn away by the same process, and to a greater depth than they now
appear to be. All of the material that once filled these valleys has
been carried down by the water filling up the bottom of the ocean and
building out the great delta of the lower Mississippi. Mountains have
been worn down and carried away by the action of the running water until
their height is much lower than in former times. The great lakes, that
were enlarged during the glacial period and in some cases wholly
created--by the scooping out and damming up of the waterways and by
piling glacial drift around their shores--have had some of their outlets
raised to a higher level, and others have been created anew.

The old river beds that formerly carried the water that is now drained
through the St. Lawrence were eroded by the action of running water to a
great depth, as is shown by numerous borings along the valley of the
Mohawk and down the Hudson. The salt wells at Syracuse, N. Y., have been
put down through glacial drifts and the salt water is found in the bed
of the old river. Great bodies of salt are found at that low level,
constantly dissolved by the water percolating through the sand and
gravel of the glacial drift. This salt water is pumped up and
evaporated, leaving the salt--forming one of the important industries of
that region. All of the rivers from the Ohio eastward tell the same
story, which is that at some remote period the land was much higher
above the level of the sea than it is to-day. The bottoms of many of
these old river beds are lower than sea-level, but as they were made by
running water they must have been at one time above that point.

There is abundant evidence that the earth sinks in some places and rises
in others. Along the ridges of some of the eastern mountains are found
in great abundance the products of the bottom of