werbefleisses_,
pp. 180-187. Stuttgart, 1899.

[320] Blanqui, History of Political Economy, pp. 150-152. New York,
1880.

[321] Carl Ritter, Comparative Geography, p. 63. New York, 1865.

[322] E. C. Semple, American History and its Geographic Conditions, pp.
42-43, 109, 110. Boston, 1903.

[323] James Bryce, Impressions of South Africa, pp. 405-6. New York,
1897.

[324] P. L. Ford, Writings of Thomas Jefferson, Vol. VIII. Letter to
John Bacon, April 30, 1803; and Confidential Message to Congress on the
Expedition to the Pacific, January 18, 1803.

[325] Emerson, The Young American, in Nature Addresses and Lectures, pp.
369-371. Centenary Edition, Boston.

CHAPTER VII

GEOGRAPHICAL BOUNDARIES

[Sidenote: The boundary zone in nature.]

Nature abhors fixed boundary lines and sudden transitions; all her
forces combine against them. Everywhere she keeps her borders melting,
wavering, advancing, retreating. If by some cataclysm sharp lines of
demarcation are drawn, she straightway begins to blur them by creating
intermediate forms, and thus establishes the boundary zone which
characterizes the inanimate and animate world. A stratum of limestone or
sandstone, when brought into contact with a glowing mass of igneous
rock, undergoes various changes due to the penetrating heat of the
volcanic outflow, so that its surface is metamorphosed as far as that
heat reaches. The granite cliff slowly deposits at its base a rock-waste
slope to soften the sudden transition from its perpendicular surface to
the level plain at its feet. The line where a land-born river meets the
sea tends to become a sandbar or a delta, created by the river-borne
silt and the wash of the waves, a form intermediate between land and
sea, bearing the stamp of each, fluid in its outlines, ever growing by
the persistent accumulation of mud, though ever subject to inundation
and destruction by the waters which made it. The alluvial coastal hems
that edge all shallow seas are such border zones, reflecting in their
flat, low surfaces the dead level of the ocean, in their composition the
solid substance of the land; but in the miniature waves imprinted on the
sands and the billows of heaped-up boulders, the master workman of the
deep leaves his mark. [See map page 243.]

Under examination, even our familiar term coastline proves to be only an
abstraction with no corresponding reality in nature. Everywhere, whether
on margin of lake or gulf, the