xceeds the Baltic in area, and the
Aral, which outranks Lake Michigan, show the closest physical
resemblance to thalassic basins, because of their size, salinity and
enclosed drainage systems; but their anthropo-geographical significance
is slight. The very salinity which groups them with the sea points to an
arid climate that forever deprives them of the densely populated coasts
characteristic of most enclosed seas, and hence reduces their historical
importance. Their tributary streams, robbed of their water by irrigation
canals, like "the shorn and parcelled Oxus", renounce their function of
highways into the interior. To this rule the Volga is a unique
exception. Finally, cut off from union with the ocean, these salt lakes
lose the supreme historical advantage which is maintained by freshwater
lakes, like Ladoga, Nyassa, Maracaibo and the Great Lakes of North
America, all lying near sea level.

[Sidenote: Lakes as fresh water seas.]

Lakes as part of a system of inland waterways may possess commercial
importance surpassing that of many seas. This depends upon the
productivity, accessibility and extent of their hinterland, and this in
turn depends upon the size and shape of the inland basin. The chain of
the five Great Lakes, which together present a coastline of four
thousand miles and a navigable course as long as the Baltic between the
Skager Rack and the head of the Gulf of Bothnia, constitutes a
freshwater Mediterranean. It has played the part of an enclosed sea in
American history and has enabled the Atlantic trade to penetrate 1400
miles inland to Chicago and Duluth. Its shores have therefore been a
coveted object of territorial expansion. The early Dutch trading posts
headed up the Hudson and Mohawk toward Lake Ontario, as did the English
settlements which succeeded them. The French, from their vantage point
at Montreal, threw out a frail casting-net of fur stations and missions,
which caught and held all the Lakes for a time. Later the American
shores were divided among eight of our states. The northern boundaries
of Indiana and Illinois were fixed by Congress for the express purpose
of giving these commonwealths access to Lake Michigan. Pennsylvania with
great difficulty succeeded in protruding her northwestern frontier to
cover a meager strip of Erie coast, while New York's frontage on the
same lake became during the period of canal and early railroad
construction, a great factor in her development.

In