at Nikolaievsk. Here they
dispose of their remaining stock and also of their barges, the lumber of
which is utilized for sidewalks, and they themselves return upstream by
steamer. The grain barges of western Siberia, like the coal barges of
the Mississippi, even within recent decades, are similarly disposed of
at the journey's end.[657] The tonnage of downstream traffic on the Ohio
and Mississippi to-day greatly exceeds that upstream. The fleet of 56
coal boats, carrying about 70,000 tons, which the great towboat Sprague
takes in a single trip from Louisville down to New Orleans, all return
empty. Of the 15,226,805 net tons of freight shipped in 1906 on the Ohio
system, 13,980,368 tons of coal, stone, sand and lumber were carried in
unrigged craft, fitted chiefly for downstream traffic.[658]

[Sidenote: Importance of mouth to upstream people.]

Owing to the strong pull exerted by a river's mouth upon all its basin,
current, commerce and people alike tend to reach the ocean. For a nation
holding the terrestrial course of a stream, the political fate of its
tidal course or mouth must always be a matter of great concern. To the
early westerner of the United States, before the acquisition of the
Louisiana country, it was of vital importance whether belligerent France
or more amenable Spain or the Republic itself should own the mouth of
the Mississippi. Germany, which holds 240 miles (400 kilometers) of the
navigable Danube,[659] can never be indifferent to the political
ownership of its mouth, or to the fact that a great power like Russia
has edged forward, by the acquisition of Bessarabia in 1878, to the
northern or Kilia debouchment channel.[660] Such interest shows itself in
sustained efforts either to gain political control of the mouth, or to
secure the neutrality of the stream by having it declared an
international waterway, and thus partially to deprive the state holding
its mouth of the advantages of its transit location.

The only satisfactory solution is undivided political ownership. After
France pushed eastward to the Rhine in 1648, she warred for three
centuries to acquire its mouth. Napoleon laid claim to Belgium and
Holland on the ground that their soil had been built up by the alluvium
of French rivers. Germany's conquest of Schleswig-Holstein in 1864 was
significant chiefly because it dislodged Denmark from the right bank of
the lower Elbe, and secured undivided control of this important estuary.
The Rhi