vation of 972 feet. As this terrace must have been originally
horizontal we have here a lake barrier, due to a difference of
elevation, amounting to over 600 feet.

In the same way we get a clue to the curious cruciform shape of the Lake
of Lucerne as contrasted with the simple outline of such lakes as those
of Neuchatel or Zurich. That of Lucerne is a complex lake. Soundings
have shown that the bottom of the Urner See is quite flat. It is in fact
the old bed of the Reuss, which originally ran, not as now by Lucerne,
but by Schwytz and through the Lake of Zug. In the same way the Alpnach
See is the old bed of the Aa, which likewise ran through the Lake of
Zug. The old river terraces of the Reuss can be traced in places between
Brunnen and Goldau. Now these terraces must have originally sloped from
the upper part downwards, from Brunnen towards Goldau. But at present
the slope is the other way, _i.e._ from Goldau towards Brunnen. From
this and other evidence we conclude that in the direction from Lucerne
towards Rapperschwyl there has been an elevation of the land, which has
dammed up the valleys and thus turned parts of the Aa and the Reuss into
lakes--the two branches of the Lake of Lucerne known as the Alpnach See
and Urner See.

During the earthquakes of 1819 while part of the Runn of Cutch, 2000
square miles in area, sunk several feet, a ridge of land, called by the
natives the Ulla-Bund or "the wall of God," thirty miles long, and in
parts sixteen miles wide, was raised across an ancient arm of the Indus,
and turned it temporarily into a lake.

In considering the great Italian lakes, which descend far below the sea
level, we must remember that the Valley of the Po is a continuation of
the Adriatic, now filled up and converted into land, by the materials
brought down from the Alps. Hence we are tempted to ask whether the
lakes may not be remains of the ancient sea which once occupied the
whole plain. Moreover just as the Seals of Lake Baikal in Siberia carry
us back to the time when that great sheet of fresh water was in
connection with the Arctic Ocean, so there is in the character of the
Fauna of the Italian lakes, and especially the presence of a Crab in the
Lake of Garda, some confirmation of such an idea. Further evidence,
however, is necessary before these interesting questions can be
definitely answered.

Lastly, some lakes and inland seas seem to be due to even greater
cosmical causes. Thus a line inclin