TOPOGRAPHIC CONTROL OF COMMERCE
The great industry of commerce, which includes both the trade in the
commodities of life and the transportation of them, is governed very
largely by the character of the earth's surface. But very few
food-stuffs can be grown economically in mountain-regions. Steep
mountain-slopes are apt to be destitute of soil; moreover, even the
mountain-valleys are apt to be difficult of access, and in such cases
the cost of moving the crops may be greater than the market value of the
products. Mountainous countries, therefore, are apt to be sparsely
peopled regions.
But although the great mountain-systems are unhabitable, or at least
sparsely peopled, they have a very definite place in the economics of
life. Thus, the great western highland of the United States diverts the
flow of moisture from the Gulf of Mexico northward into the central
plain, and gives to the region most of its food-growing power. In a
similar manner, moisture intercepted by the Alps and the Himalayas has
not only created the plains of the Po and the Ganges from the rock-waste
carried from the slopes, but has also made them exceedingly fertile.
Mountain-ranges are also valuable for their contents. The broken
condition of the rock-folds and the rapid weathering to which they are
subjected have exposed the minerals and metals so useful in the arts of
commerce and civilization. Thus, the weathering of the Appalachian folds
has made accessible about the only available anthracite coal measures
yet worked; and the worn folds about Lake Superior have yielded the
ores that have made the United States the foremost copper and steel
manufacturing country of the world. Gold, silver, tin, lead, zinc,
platinum, granite, slate, and marble occur mainly in mountain-folds.
=Mountains and Valleys.=--Mountain-ranges are great obstacles to commerce
and intercommunication. The Greek peoples found it much easier to
scatter along the Mediterranean coast than to cross the Balkan
Mountains. For twenty years after the settlement of California, it was
easier and less expensive to send traffic by way of Cape Horn than to
carry it across the Rocky Mountains.
The deep cañons of mountainous regions are quite as difficult to
overcome as the high ranges. In modern methods of transportation a range
that cannot be surmounted may be tunnelled, and a tunnel five or six
miles in length is no uncommon feat of engineering. A cañon, however,
cannot be tunnelled, and if too wide for cantilever or suspension
bridges, a detour of many miles is necessary. In crossing a deep chasm
the route of transportation may aggregate ten or fifteen times the
distance spanned by a straight line.
Excepting the mining regions, the population of mountainous countries is
apt to be found mainly in the intermontane valleys. A reason for this is
not hard to find; the valleys are usually filled with rich soil brought
from the higher slopes and levelled by the water. The population,
therefore, is concentrated in the valley because of the food-producing
power of the land. For this reason the Sound, Willamette, and San
Joaquin-Sacramento Valleys contain the chief part of the Pacific coast
population. The Shenandoah and the Great Valley of Virginia are similar
instances.
What is true of the larger intermontane valleys is true also of the
narrow stream valleys of mountain and plateau regions. Thus, in the New
England plateau the chief growth during the past forty years has been in
the valley lands. In that time if the uplands have not suffered actual
loss, they certainly have made no material gains. Upland farming has not
proved a remunerative venture, and many of the farms have either been
abandoned or converted to other uses.
=Passes.=--Transverse valleys form very important topographic features of
mountain-regions. Inasmuch as the ranges themselves are obstacles to
communication, it follows that the latter must be concentrated at such
cross valleys or gaps as may be traversed. Khaibar Pass, a narrow defile
in the Hindu Kush Mountains, between Peshawur and Jelalabad, for many
years was the chief gateway between Europe and India. Even now the cost
of holding it is an enormous tax upon England.
Brenner, St. Gotthard, and the Mont Cenis Passes are about the only land
channels of commerce between Italy and transalpine Europe, and most of
the communication between northern Italy and the rest of Europe is
carried on by means of these passes. Every transcontinental railway of
the American continent crosses the various highlands by means of gaps
and passes, and some of them would never have been built were it not for
the existence of the passes. Fremont, South, and Marshall Passes have
been of historic importance for half a century.
The Hudson and Champlain Valley played an important part in the history
of the colonies a century before the existence of the United States, and
its importance as a gateway to eastern Canada is not likely to be
lessened. The Mohawk gap was the first practical route to be maintained
between the Atlantic seaboard and the food-producing region of the Great
Central Plain. It is to-day the most important one. It is so nearly
level that the total lift of freight going from Buffalo to tide-water is
less than five hundred feet.
[Illustration: A PASS--THE ROUTE OF A RAILWAY]
=Rivers.=--River-valleys are closely connected with the economic
development of a country. Navigable rivers are free and open highways of
communication. In newly settled countries the river is always the least
expensive means of carriage, and often it is the only one available for
the transportation of heavy goods.
In late years, since the railway has become the chief means for the
transportation of commodities, river transportation has greatly
declined. The river-valley, however, has lost none of its importance; in
most instances it is a naturally levelled and graded route, highly
suitable for the tracks of the railway. As a result, outside of the
level lands of the Great Central Plain, not far from eighty per cent. of
the railway mileage of the United States is constructed along
river-valleys.
=Plateaus.=--Plateaus are usually characterized by broken and more or less
rugged surface features. As a rule they are deficient in the amount of
rainfall necessary to produce an abundance of the grains and similar
food-stuffs, although this is by no means the case with all.
Most plateaus produce an abundance of grass, and cattle-growing is
therefore an important industry in such regions. Thus, the plateaus of
the Rocky Mountains are famous for cattle, and the same is true of the
Mexican and the South American plateaus. The Iberian plateau, including
Spain and Portugal, is noted for the merino sheep, which furnish the
finest wool known. The plateau of Iran is also noted for its wool, and
the rugs from this region cannot be imitated elsewhere in the world.
=Plains.=--Plains are of the highest importance to life and its
activities. Not only do they present fewer obstacles to
intercommunication than any other topographic features, but almost
always they are deeply covered with the fine rock-waste that forms the
chief components of soil. Plains, therefore, contain the elements of
nutrition, and are capable of supporting life to a greater extent than
either mountains or plateaus. About ninety per cent. of the world's
population dwell in the lowland plains.
The Great Central Plain of North America produces more than one-quarter
of the world's wheat, and about four-fifths of the corn. The southern
part of the great Arctic plain, and its extension, the plains of the
Baltic also yield immense quantities of grain and cattle products. The
coast-plains of the Atlantic Ocean, on both the American and the
European side, are highly productive.
River flood-plains are almost always densely peopled because of their
productivity. The bottom-lands of the Mississippi and the Yangtze Rivers
are among the chief food-producing regions of the world. Lacustrine
plains, the beds of former lakes, are also highly productive regions.
The valley of the Red River of the North is an example, and its wheat is
of a very high quality.
Fertile coast-plains and lowlands that are adjacent to good harbors, as
a rule are the most thickly peopled regions of the world. In many such
regions the density of population exceeds two hundred or more per square
mile. The reason is obvious. Life seeks that environment which yields
the greatest amount of nutrition with the least expenditure of energy.
The study of a good relief map shows that, as a rule, the Pacific Ocean
is bordered by a rugged highland, which has a more or less abrupt slope,
and a narrow coast-plain. Indeed, the latter is absent for the greater
part. The slopes of the Atlantic, on the other hand, are long and
gentle--being a thousand miles or more in width throughout the greater
part of their extent. The area of productive land is correspondingly
great, and the character of the surface features is such that
intercommunication is easy.
[Illustration: A RIVER FLOOD-PLAIN--A REGION ADAPTED TO CULTIVATION]
The result of these conditions is evident. The Atlantic slopes, though
not everywhere the most densely peopled areas, contain the great centres
of the world's activities and economies. In the past 400 years they have
not only overtaken the Pacific coast races, but have far surpassed them.
They are now entering upon a commercial invasion of the Pacific nations
that is resulting in a reorganization of the entire industrial world.
=Topography and Trade Routes.=--As the settlement and commerce of a
country grow, roads succeed trails, and trails are apt to follow the
paths of migrating animals. Until the time of the Civil War in the
United States, most of the great highways of the country were the direct
descendants of "buffalo roads," as they were formerly called.
In the crossing of divides from one river-valley to another, the
mountain-sections of the railways for the greater part follow the trails
of the bison. This is especially marked in the Pennsylvania, the
Baltimore and Ohio, and the Chesapeake and Ohio railways; in some
instances the tunnels through ranges have been constructed directly
under the trails. The reason is obvious; the instinct of the bison led
him along routes having the minimum of grade.
Throughout the Mississippi Valley and the great plains the Indian trails
usually avoided the bottom-lands of the river-valleys, following the
divides and portages instead. This selection of routes was probably due
to the fact that the lowlands were swampy and subject to overflow; the
portages and divides offered no steep grades, and were therefore more
easily traversed.
[Illustration: WHERE COMMODITIES ARE EXCHANGED--NEW YORK CITY
WATER-FRONT]
=Harbors.=--Coast outlines have much to do with the commercial
possibilities of a region. The "drowned valleys" and similar inlets
along the North Atlantic coast, both of Europe and America, form harbors
in which vessels ride at anchor in safety, no matter what the existing
conditions outside may be. As a result, the two greatest centres of
commerce in the world are found at these harbors--one on the American,
the other on the European coast.
From New York Bay southward along the Atlantic seaboard there are but
few harbors, and this accounts for the enormous development of commerce
in the stretch of coast between Portland and Baltimore. San Francisco
Bay and the harbors of Puget Sound monopolize most of the commerce of
the Pacific coast of the United States. South America has several good
harbors on the Atlantic seaboard, and in consequence a large city has
grown at the site of each. On the Pacific coast the good harbors are
very few in number, and they are not situated near productive regions.
Asiatic peoples, as a rule, are not promoters of foreign commerce, and,
those of Japan excepted, the only good harbors are those that have been
improved by European governments. These are confined mainly to India and
China. The many possible harbors make certain a tremendous commerce in
the future. Africa has but very few good harbors. There are excellent
harbors in the islands of the Pacific, and many of them are of great
strategic value as coaling stations and bases of supply to the various
maritime powers.
QUESTIONS FOR DISCUSSION
The Pennsylvania Railroad has found it more economical to tunnel the
mountain-range under Horseshoe Curve, near Altoona, than to haul the
trains over the mountains; discuss the details in which there will be a
saving.
Why are rugged and mountainous regions apt to be sparsely peopled?
The first valuable discovery in the Rocky Mountains was gold; what were
the chief effects that resulted?
Would the industries of the Pacific coast of the United States be
benefited or impaired by the existence of a coast-plain?
Which are more conducive to commerce--the large mediterraneans, such as
the Gulf of Mexico, or the small estuaries, such as New York Bay?
Discuss the merits or demerits of each.
What are the chief products of mountains, of plateaus, of lowland
plains?
COLLATERAL READING AND REFERENCE
Adams's New Empire--Chapter I.
Redway's Physical Geography--Chapter IV.
A topographic map of the United States.
[Illustration: MEAN ANNUAL RAINFALL]