from which the track of the South Seas is inconveniently
remote. Hence we find in recent decades a reversion to the old east-west
path along the southern rim of Eurasia, now perfected by the Suez Canal,
and to be extended in the near future around the world by the union of
the Pacific with the Caribbean Sea at Panama; so that finally the
northern hemisphere will have its own circum-mundane waterway, along the
line of greatest intercontinental intercourse.

[Sidenote: Size of the oceans]

The size of the ocean as a whole is so enormous, and yet its various
subdivisions are so uniform in their physical aspect, that their
differences of size produce less conspicuous historical effects than
their diversity of area would lead one to expect. A voyage across the
177,000 square miles (453,500 square kilometers) of the Black Sea does
not differ materially from one across the 979,000 square miles
(2,509,500 square kilometers) of the Mediterranean; or a voyage across
the 213,000 square miles (547,600 square kilometers) of the North Sea,
from one across the three-hundredfold larger area of the Pacific. The
ocean does not, like the land, wear upon its surface the evidences and
effects of its size; it wraps itself in the same garment of blue waves
or sullen swell, wherever it appears; but the outward cloak of the land
varies from zone to zone. The significant anthropo-geographical
influence of the size of the oceans, as opposed to that of the smaller
seas, comes from the larger circle of lands which the former open to
maritime enterprise. For primitive navigation, when the sailor crept
from headland to headland and from island to island, the small enclosed
basin with its close-hugging shores did indeed offer the best
conditions. To-day, only the great tonnage of ocean-going vessels may
reflect in some degree the vast areas they traverse between continent
and continent. Coasting craft and ships designed for local traffic in
enclosed seas are in general smaller, as in the Baltic, though the
enormous commerce of the Great Lakes, which constitute in effect an
inland sea, demands immense vessels.

[Sidenote: Neutrality of the seas, its evolution.]

The vast size of the oceans has been the basis of their neutrality. The
neutrality of the seas is a recent idea in political history. The
principle arose in connection with the oceans, and from them was
extended to the smaller basins, which previously tended to be regarded
as private polit