.

[627] H.D. Traill, Social England, Vol. III, pp. 363-364, 540. London
and New York, 1895.

[628] J. Partsch, Central Europe, p. 311. London, 1903.

[629] Alexander P. Engelhardt, A Russian Province of the North, pp.
54-71. From the Russian. London, 1899.

CHAPTER XI

THE ANTHROPO-GEOGRAPHY OF RIVERS

[Sidenote: Rivers as intermediaries between land and sea.]

To a large view, rivers appear in two aspects. They are either part of
the general water envelope of the earth, extensions of seas and
estuaries back into the up-hill reaches of the land, feeders of the
ocean, roots which it spreads out over the surface of the continents,
not only to gather its nourishment from ultimate sources in spring and
glacier, but also to bring down to the coast the land-born products of
the interior to feed a sea-born commerce; or rivers are one of the land
forms, merely water filling valley channels, serving to drain the fields
and turn the mills of men. In the first aspect their historical
importance has been both akin and linked to that of the ocean, despite
the freshness and smaller volume of their waters and the unvarying
direction of their currents. The ocean draws them and their trade to its
vast basin by the force of gravity. It unites with its own the history
of every log-stream in Laurentian or Himalayan forest, as it formerly
linked the beaver-dammed brooks of wintry Canada with the current of
trade following the Gulf Stream to Europe.

Where sea and river meet, Nature draws no sharp dividing line. Here the
indeterminate boundary zone is conspicuous. The fresh water stream
merges into brackish estuary, estuary into saltier inlet and inlet into
briny ocean. Closely confined sea basins like the Black and Baltic,
located in cool regions of slight evaporation and fed from a large
catchment basin, approach in their reduced salinity the fresh water
lakes and coastal lagoons in which rivers stretch out to rest on their
way to the ocean. The muddy current of the Yangtze Kiang colors the
Yellow Sea, and warns incoming Chinese junks of the proximity of land
many hours before the low-lying shores can be discerned.[630] Columbus,
sailing along the Caribbean coast of South America off the Orinoco
mouth, found the ocean waters brackish and surmised the presence of a
large river and therefore a large continent on his left.[631]

The transitional form between stream and pelagic inlet found in every
river mouth is emphasized