ough the men who live on these mountains have thus made three
countries out of them, the whole region is in nature one. It constitutes
one mighty mass of mountainous land, which is lifted up so high into the
air that all the summits rise into the regions of intense and perpetual
cold, and so condense continually, from the atmosphere, inexhaustible
quantities of rain and snow.

The water which falls upon this mountainous region must of course find
its way to the sea. In doing so the thousands of smaller torrents unite
with each other into larger and larger streams, until at length they
make four mighty rivers--the largest and most celebrated in Europe. All
the streams of the southern slopes of the mountains form one great
river, which flows east into the Adriatic. This river is the Po. On the
western side the thousands of mountain torrents combine and form the
Rhone, which, making a great bend, turns to the southward, and flows
into the Mediterranean. On the eastern side the water can find no escape
till it has traversed the whole continent to the eastward, and reached
the Black Sea. This stream is the Danube. And finally, on the north the
immense number of cascades and torrents which come out from the
glaciers, or pour down the ravines, or meander through the valleys, or
issue from the lakes, of the northern slope of the mountains, combine at
Basle, and flow north across the whole continent, nearly six hundred
miles, to the North Sea. This river is the Rhine.

All this, which I have thus been explaining, may be seen very clearly
if you turn to any map of Europe, and find the mountainous region in the
centre, and then trace the courses of the four great rivers, as I have
described them.

It would seem that the country through which the River Rhine now flows
was at first very uneven, presenting valleys and broad depressions,
which the waters of the river filled, thus forming great shallow lakes,
that extended over very considerable tracts of country. In process of
time, however, these lakes became filled with the sediment which was
brought down by the river, and thus great flat plains of very rich and
level land were formed. At every inundation of the river, of course,
these plains, or intervals, as they are sometimes called, would be
overflowed, and fresh deposits would be laid upon them; so that in the
course of ages the surface of them would rise several feet above the
ordinary level of the river. In fact they would