d of leaving the rock naked,
as in the Laurentian region, it merely smoothed off many of the
irregularities of the surface and covered large areas with the most
fertile soil.

In doing this, to be sure, the ice-cap scoured some hollows and left a
vastly larger number of basins surrounded in whole or in part by glacial
debris. These have given rise to the innumerable lakes, large and small,
whose beauty so enhances the charms of Canada, New England, New York,
Minnesota, and other States. They serve as reservoirs for the water
supply of towns and power plants and as sources of ice and fish. Though
they take land from agriculture, they probably add to the life of
the community as much in other ways as they detract in this. Moreover
glaciation diverted countless streams from their old courses and made
them flow over falls and rapids from which water-power can easily be
developed. That is one reason why glaciated New England contains over
forty per cent of all the developed water-power in the United States.

Far more important, however, than the glacial lakes and rivers is the
fertile glacial soil. It comes fresh from the original rocks and has not
yet been exhausted by hundreds of thousands of years of weathering.
It also has the advantage of being well mixed, for generally it is the
product of scrapings from many kinds of rocks, each of which contributes
its own particular excellence to the general composition. Take Wisconsin
as an example. * Most parts of that State have been glaciated, but in
the southwest there lies what is known as the "driftless area" because
it is not covered with the "drift" or glacial debris which is thickly
strewn over the rest of the State. A comparison of otherwise similar
counties lying within and without the driftless area shows an
astonishing contrast. In 1910 the average value of all the farm land in
twenty counties covered with drift amounted to $56.90 per acre. In six
counties partly covered with drift and partly driftless the value was
$59.80 per acre, while in thirteen counties in the driftless area it was
only $33.30 per acre. In spite of the fact that glaciation causes swamps
and lakes, the proportion of land cultivated in the glaciated areas is
larger than in the driftless. In the glaciated area 61 per cent of the
land is improved and in the driftless area only 43.5 per cent. Moreover,
even though the underlying rock and the original topography be of the
same kind in both cases, the