Chapter VI: Front Matter (6)

The simple classification employed by Professor James Geikie[35] into
mountains of accumulation, mountains of elevation and mountains of
circumdenudation, is not considered sufficiently thorough by German
geographers, who, following Richthofen, generally adopt a
classification dependent on six primary divisions, each of which is
subdivided. The terms employed, especially for the subdivisions,
cannot be easily translated into other languages, and the English
equivalents in the following table are only put forward tentatively:--

RICHTHOFEN'S CLASSIFICATION OF MOUNTAINS[36]

I. _Tektonische Gebirge_--Tectonic mountains.
(a) _Bruchgebirge oder Schollengebirge_--Block mountains.
1. _Einseitige Schollengebirge oder Schollenrandgebirge_--
Scarp or tilted block mountains.
(i.) _Tafelscholle_--Table blocks.
(ii.) _Abrasionsscholle_--Abraded blocks.
(iii.) _Transgressionsscholle_--Blocks of unconformable
strata.
2. _Flexurgebirge_--Flexure mountains.
3. _Horstgebirge_--Symmetrical block mountains.
(b) _Faltungsgebirge_--Fold mountains.
1. _Homoomorphe Faltungsgebirge_--Homomorphic fold mountains.
2. _Heteromorphe Faltungsgebirge_--Heteromorphic fold
mountains.

II. _Rumpfgebirge oder Abrasionsgebirge_--Trunk or abraded mountains.

III. _Ausbruchsgebirge_--Eruptive mountains.

IV. _Aufschuttungsgebirge_--Mountains of accumulation.

V. _Flachboden_--Plateaux.
(a) _Abrasionsplatten_--Abraded plateaux.
(b) _Marines Flachland_--Plain of marine erosion.
(c) _Schichtungstafelland_--Horizontally stratified tableland.
(d) _Ubergusstafelland_--Lava plain.
(e) _Stromflachland_--River plain.
(f) _Flachboden der atmospharischen Aufschuttung_--Plains of
aeolian formation.

VI. _Erosionsgebirge_--Mountains of erosion.

Mountain forms.

From the morphological point of view it is more important to
distinguish the associations of forms, such as the _mountain mass_ or
group of mountains radiating from a centre, with the valleys furrowing
their flanks spreading towards every direction; the _mountain chain_
or line of heights, forming a long narrow ridge or series of ridges
separated by parallel valleys; the _dissected plateau_ or highland,
divided into mountains of circumdenudation by a system of deeply-cut
valleys; and the _isolated peak_, usually a volcanic cone or a hard
rock mass left projecting after the softer strata which embedded it
have been worn away (Monadnock of Professor Davis).

Distribution of mountains.

The geographical distribution of mountains is intimately associated
with the great structural lines of the continents of which they form
the culminating region. Lofty lines of fold mountains form the
"backbones" of North America in the Rocky Mountains and the west coast
systems, of South America in the Cordillera of the Andes, of Europe in
the Pyrenees, Alps, Carpathians and Caucasus, and of Asia in the
mountains of Asia Minor, converging on the Pamirs and diverging thence
in the Himalaya and the vast mountain systems of central and eastern
Asia. The remarkable line of volcanoes around the whole coast of the
Pacific and along the margin of the Caribbean and Mediterranean seas
is one of the most conspicuous features of the globe.

Functions of land forms.

Land waste.

Glaciers.

If land forms may be compared to organs, the part they serve in the
economy of the earth may, without straining the term, be characterized
as functions. The first and simplest function of the land surface is
that of guiding loose material to a lower level. The downward pull of
gravity suffices to bring about the fall of such material, but the
path it will follow and the distance it will travel before coming to
rest depend upon the land form. The loose material may, and in an arid
region does, consist only of portions of the higher parts of the
surface detached by the expansion and contraction produced by heating
and cooling due to radiation. Such broken material rolling down a
uniform scarp would tend to reduce its steepness by the loss of
material in the upper part and by the accumulation of a mound or scree
against the lower part of the slope. But where the side is not a
uniform scarp, but made up of a series of ridges and valleys, the
tendency will be to distribute the detritus in an irregular manner,
directing it away from one place and collecting it in great masses in
another, so that in time the land form assumes a new appearance. Snow
accumulating on the higher portions of the land, when compacted into
ice and caused to flow downwards by gravity, gives rise, on account of
its more coherent character, to continuous glaciers, which mould
themselves to the slopes down which they are guided, different
ice-streams converging to send forward a greater volume. Gradually
coming to occupy definite beds, which are deepened and polished by the
friction, they impress a characteristic appearance on the land, which
guides them as they traverse it, and, although the ice melts at lower
levels, vast quantities of clay and broken stones are brought down and
deposited in terminal moraines where the glacier ends.

Rain.

River systems.

Adjustment of rivers to land.

Rain is by far the most important of the inorganic mobile
distributions upon which land forms exercise their function of
guidance and control. The precipitation of rain from the aqueous
vapour of the atmosphere is caused in part by vertical movements of
the atmosphere involving heat changes and apparently independent of
the surface upon which precipitation occurs; but in greater part it is
dictated by the form and altitude of the land surface and the
direction of the prevailing winds, which itself is largely influenced
by the land. It is on the windward faces of the highest ground, or
just beyond the summit of less dominant heights upon the leeward side,
that most rain falls, and all that does not evaporate or percolate
into the ground is conducted back to the sea by a route which depends
only on the form of the land. More mobile and more searching than ice
or rock rubbish, the trickling drops are guided by the deepest lines
of the hillside in their incipient flow, and as these lines converge,
the stream, gaining strength, proceeds in its torrential course to
carve its channel deeper and entrench itself in permanent occupation.
Thus the stream-bed, from which at first the water might be blown away
into a new channel by a gale of wind, ultimately grows to be the
strongest line of the landscape. As the main valley deepens, the
tributary stream-beds are deepened also, and gradually cut their way
headwards, enlarging the area whence they draw their supplies. Thus
new land forms are created--valleys of curious complexity, for
example--by the "capture" and diversion of the water of one river by
another, leading to a change of watershed.[37] The minor tributaries
become more numerous and more constant, until the system of torrents
has impressed its own individuality on the mountain side. As the river
leaves the mountain, ever growing by the accession of tributaries, it
ceases, save in flood time, to be a formidable instrument of
destruction; the gentler slope of the land surface gives to it only
power sufficient to transport small stones, gravel, sand and
ultimately mud. Its valley banks are cut back by the erosion of minor
tributaries, or by rain-wash if the climate be moist, or left steep
and sharp while the river deepens its bed if the climate be arid. The
outline of the curve of a valley's sides ultimately depends on the
angle of repose of the detritus which covers them, if there has been
no subsequent change, such as the passage of a glacier along the
valley, which tends to destroy the regularity of the cross-section.
The slope of the river bed diminishes until the plain compels the
river to move slowly, swinging in _meanders_ proportioned to its size,
and gradually, controlled by the flattening land, ceasing to transport
material, but raising its banks and silting up its bed by the dropped
sediment, until, split up and shoaled, its distributaries struggle
across its delta to the sea. This is the typical river of which there
are infinite varieties, yet every variety would, if time were given,
and the land remained unchanged in level relatively to the sea,
ultimately approach to the type. Movements of the land either of
subsidence or elevation, changes in the land by the action of erosion
in cutting back an escarpment or cutting through a col, changes in
climate by affecting the rainfall and the volume of water, all tend to
throw the river valley out of harmony with the actual condition of its
stream. There is nothing more striking in geography than the
perfection of the adjustment of a great river system to its valleys
when the land has remained stable for a very lengthened period. Before
full adjustment has been attained the river bed may be broken in
places by waterfalls or interrupted by lakes; after adjustment the bed
assumes a permanent outline, the slope diminishing more and more
gradually, without a break in its symmetrical descent. Excellent
examples of the indecisive drainage of a new land surface, on which
the river system has not had time to impress itself, are to be seen in
northern Canada and in Finland, where rivers are separated by scarcely
perceptible divides, and the numerous lakes frequently belong to more
than one river system.

The geographical cycle.

The action of rivers on the land is so important that it has been made
the basis of a system of physical geography by Professor W.M. Davis,
who classifies land surfaces in terms of the three factors--structure,
process and time.[38] Of these time, during which the process is
acting on the structure, is the most important. A land may thus be
characterized by its position in the "geographical cycle", or cycle of
erosion, as young, mature or old, the last term being reached when the
base-level of erosion is attained, and the land, however varied its
relief may have been in youth or maturity, is reduced to a nearly
uniform surface or peneplain. By a re-elevation of a peneplain the
rivers of an old land surface may be restored to youthful activity,
and resume their shaping action, deepening the old valleys and
initiating new ones, starting afresh the whole course of the
geographical cycle. It is, however, not the action of the running
water on the land, but the function exercised by the land on the
running water, that is considered here to be the special province of
geography. At every stage of the geographical cycle the land forms, as
they exist at that stage, are concerned in guiding the condensation
and flow of water in certain definite ways. Thus, for example, in a
mountain range at right angles to a prevailing sea-wind, it is the
land forms which determine that one side of the range shall be richly
watered and deeply dissected by a complete system of valleys, while
the other side is dry, indefinite in its valley systems, and sends
none of its scanty drainage to the sea. The action of rain, ice and
rivers conspires with the movement of land waste to strip the layer of
soil from steep slopes as rapidly as it forms, and to cause it to
accumulate on the flat valley bottoms, on the graceful flattened cones
of alluvial fans at the outlet of the gorges of tributaries, or in the
smoothly-spread surface of alluvial plains.

The whole question of the regime of rivers and lakes is sometimes
treated under the name hydrography, a name used by some writers in the
sense of marine surveying, and by others as synonymous with
oceanography. For the study of rivers alone the name potamology[39]
has been suggested by Penck, and the subject being of much practical
importance has received a good deal of attention.[40]

Lakes and internal drainage.

The study of lakes has also been specialized under the name of
limnology (see LAKE).[41] The existence of lakes in hollows of the
land depends upon the balance between precipitation and evaporation. A
stream flowing into a hollow will tend to fill it up, and the water
will begin to escape as soon as its level rises high enough to reach
the lowest part of the rim. In the case of a large hollow in a very
dry climate the rate of evaporation may be sufficient to prevent the
water from ever rising to the lip, so that there is no outflow to the
sea, and a basin of internal drainage is the result. This is the case,
for instance, in the Caspian sea, the Aral and Balkhash lakes, the
Tarim basin, the Sahara, inner Australia, the great basin of the
United States and the Titicaca basin. These basins of internal
drainage are calculated to amount to 22% of the land surface. The
percentages of the land surface draining to the different oceans are
approximately--Atlantic, 34.3%; Arctic sea, 16.5%; Pacific, 14.4%;
Indian Ocean, 12.8%.[42]

Terminology of river systems.

The parts of a river system have not been so clearly defined as is
desirable, hence the exaggerated importance popularly attached to "the
source" of a river. A well-developed river system has in fact many
equally important and widely-separated sources, the most distant from
the mouth, the highest, or even that of largest initial volume not
being necessarily of greater geographical interest than the rest. The
whole of the land which directs drainage towards one river is known as
its basin, catchment area or drainage area--sometimes, by an incorrect
expression, as its valley or even its watershed. The boundary line
between one drainage area and others is rightly termed the watershed,
but on account of the ambiguity which has been tolerated it is better
to call it water-parting or, as in America, divide. The only other
important term which requires to be noted here is _talweg_, a word
introduced from the German into French and English, and meaning the
deepest line along the valley, which is necessarily occupied by a
stream unless the valley is dry.

The functions of land forms extend beyond the control of the
circulation of the atmosphere, the hydrosphere and the water which is
continually being interchanged between them; they are exercised with
increased effect in the higher departments of biogeography and
anthropogeography.

Biogeography.

The sum of the organic life on the globe is termed by some geographers
the biosphere, and it has been estimated that the whole mass of living
substance in existence at one time would cover the surface of the
earth to a depth of one-fifth of an inch.[43] The distribution of
living organisms is a complex problem, a function of many factors,
several of which are yet but little known. They include the biological
nature of the organism and its physical environment, the latter
involving conditions in which geographical elements, direct or
indirect, preponderate. The direct geographical elements are the
arrangement of land and sea (continents and islands standing in sharp
contrast) and the vertical relief of the globe, which interposes
barriers of a less absolute kind between portions of the same land
area or oceanic depression. The indirect geographical elements, which,
as a rule, act with and intensify the direct, are mainly climatic; the
prevailing winds, rainfall, mean and extreme temperatures of every
locality depending on the arrangement of land and sea and of land
forms. Climate thus guided affects the weathering of rocks, and so
determines the kind and arrangement of soil. Different species of
organisms come to perfection in different climates; and it may be
stated as a general rule that a species, whether of plant or animal,
once established at one point, would spread over the whole zone of the
climate congenial to it unless some barrier were interposed to its
progress. In the case of land and fresh-water organisms the sea is the
chief barrier; in the case of marine organisms, the land. Differences
in land forms do not exert great influence on the distribution of
living creatures directly, but indirectly such land forms as mountain
ranges and internal drainage basins are very potent through their
action on soil and climate. A snow-capped mountain ridge or an arid
desert forms a barrier between different forms of life which is often
more effective than an equal breadth of sea. In this way the surface
of the land is divided into numerous natural regions, the flora and
fauna of each of which include some distinctive species not shared by
the others. The distribution of life is discussed in the various
articles in this _Encyclopaedia_ dealing with biological, botanical
and zoological subjects.[44]

Floral zones.

The classification of the land surface into areas inhabited by
distinctive groups of plants has been attempted by many
phyto-geographers, but without resulting in any scheme of general
acceptance. The simplest classification is perhaps that of Drude
according to climatic zones, subdivided according to continents. This
takes account of--(1) the _Arctic-Alpine_ zone, including all the
vegetation of the region bordering on perpetual snow; (2) the _Boreal_
zone, including the temperate lands of North America, Europe and Asia,
all of which are substantially alike in botanical character; (3) the
_Tropical_ zone, divided sharply into (a) the tropical zone of the New
World, and (b) the tropical zone of the Old World, the forms of which
differ in a significant degree; (4) the _Austral_ zone, comprising all
continental land south of the equator, and sharply divided into three
regions the floras of which are strikingly distinct--(a) South
American, (b) South African and (c) Australian; (5) the _Oceanic_,
comprising all oceanic islands, the flora of which consists
exclusively of forms whose seeds could be drifted undestroyed by ocean
currents or carried by birds. To these might be added the antarctic,
which is still very imperfectly known. Many subdivisions and
transitional zones have been suggested by different authors.

Vegetation areas.

From the point of view of the economy of the globe this classification
by species is perhaps less important than that by mode of life and
physiological character in accordance with environment. The following
are the chief areas of vegetational activity usually recognized: (1)
The ice-deserts of the arctic and antarctic and the highest mountain
regions, where there is no vegetation except the lowest forms, like
that which causes "red snow." (2) The tundra or region of intensely
cold winters, forbidding tree-growth, where mosses and lichens cover
most of the ground when unfrozen, and shrubs occur of species which in
other conditions are trees, here stunted to the height of a few
inches. A similar zone surrounds the permanent snow on lofty mountains
in all latitudes. The tundra passes by imperceptible gradations into
the moor, bog and heath of warmer climates. (3) The temperate forests
of evergreen or deciduous trees, according to circumstances, which
occupy those parts of both temperate zones where rainfall and sunlight
are both abundant. (4) The grassy steppes or prairies where the
rainfall is diminished and temperatures are extreme, and grass is the
prevailing form of vegetation. These pass imperceptibly into--(5) the
arid desert, where rainfall is at a minimum, and the only plants are
those modified to subsist with the smallest supply of water. (6) The
tropical forest, which represents the maximum of plant luxuriance,
stimulated by the heaviest rainfall, greatest heat and strongest
light. These divisions merge one into the other, and admit of almost
indefinite subdivision, while they are subject to great modifications
by human interference in clearing and cultivating. Plants exhibit the
controlling power of environment to a high degree, and thus vegetation
is usually in close adjustment to the bolder geographical features of
a region.

Faunal realms.

The divisions of the earth into faunal regions by Dr P.L. Sclater have
been found to hold good for a large number of groups of animals as
different in their mode of life as birds and mammals, and they may
thus be accepted as based on nature. They are six in number: (1)
_Palaearctic_, including Europe, Asia north of the Himalaya, and
Africa north of the Sahara; (2) _Ethiopian_, consisting of Africa
south of the Atlas range, and Madagascar; (3) _Oriental_, including
India, Indo-China and the Malay Archipelago north of Wallace's line,
which runs between Bali and Lombok; (4) _Australian_, including
Australia, New Zealand, New Guinea and Polynesia; (5) _Nearctic_ or
North America, north of Mexico; and (6) _Neotropical_ or South
America. Each of these divisions is the home of a special fauna, many
species of which are confined to it alone; in the Australian region,
indeed, practically the whole fauna is peculiar and distinctive,
suggesting a prolonged period of complete biological isolation. In
some cases, such as the Ethiopian and Neotropical and the Palaearctic
and Nearctic regions, the faunas, although distinct, are related,
several forms on opposite sides of the Atlantic being analogous, e.g.
the lion and puma, ostrich and rhea. Where two of the faunal realms
meet there is usually, though not always, a mixing of faunas. These
facts have led some naturalists to include the Palaearctic and
Nearctic regions in one, termed _Holarctic_, and to suggest
transitional regions, such as the _Sonoran_, between North and South
America, and the _Mediterranean_, between Europe and Africa, or to
create sub-regions, such as Madagascar and New Zealand. Oceanic
islands have, as a rule, distinctive faunas and floras which resemble,
but are not identical with, those of other islands in similar
positions.

Biological distribution as a means of geographical research.

The study of the evolution of faunas and the comparison of the faunas
of distant regions have furnished a trustworthy instrument of
pre-historic geographical research, which enables earlier geographical
relations of land and sea to be traced out, and the approximate
period, or at least the chronological order of the larger changes, to
be estimated. In this way, for example, it has been suggested that a
land, "Lemuria," once connected Madagascar with the Malay Archipelago,
and that a northern extension of the antarctic land once united the
three southern continents.

The distribution of fossils frequently makes it possible to map out
approximately the general features of land and sea in long-past
geological periods, and so to enable the history of crustal relief to
be traced.[45]

Reaction of organisms on environment.

While the tendency is for the living forms to come into harmony with
their environment and to approach the state of equilibrium by
successive adjustments if the environment should happen to change, it
is to be observed that the action of organisms themselves often tends
to change their environment. Corals and other quick-growing calcareous
marine organisms are the most powerful in this respect by creating new
land in the ocean. Vegetation of all sorts acts in a similar way,
either in forming soil and assisting in breaking up rocks, in filling
up shallow lakes, and even, like the mangrove, in reclaiming wide
stretches of land from the sea. Plant life, utilizing solar light to
combine the inorganic elements of water, soil and air into living
substance, is the basis of all animal life. This is not by the supply
of food alone, but also by the withdrawal of carbonic acid from the
atmosphere, by which vegetation maintains the composition of the air
in a state fit for the support of animal life. Man in the primitive
stages of culture is scarcely to be distinguished from other animals
as regards his subjection to environment, but in the higher grades of
culture the conditions of control and reaction become much more
complicated, and the department of anthropogeography is devoted to
their consideration.

Anthropogeography.

The first requisites of all human beings are food and protection, in
their search for which men are brought into intimate relations with
the forms and productions of the earth's surface. The degree of
dependence of any people upon environment varies inversely as the
degree of culture or civilization, which for this purpose may perhaps
be defined as the power of an individual to exercise control over the
individual and over the environment for the benefit of the community.
The development of culture is to a certain extent a question of race,
and although forming one species, the varieties of man differ in
almost imperceptible gradations with a complexity defying
classification (see ANTHROPOLOGY). Professor Keane groups man round
four leading types, which may be named the black, yellow, red and
white, or the Ethiopic, Mongolic, American and Caucasic. Each may be
subdivided, though not with great exactness, into smaller groups,
either according to physical characteristics, of which the form of the
head is most important, or according to language.

Types of man.

The black type is found only in tropical or sub-tropical countries,
and is usually in a primitive condition of culture, unless educated by
contact with people of the white type. They follow the most primitive
forms of religion (mainly fetishism), live on products of the woods or
of the chase, with the minimum of work, and have only a loose
political organization. The red type is peculiar to America,
inhabiting every climate from polar to equatorial, and containing
representatives of many stages of culture which had apparently
developed without the aid or interference of people of any other race
until the close of the 15th century. The yellow type is capable of a
higher culture, cherishes higher religious beliefs, and inhabits as a
rule the temperate zone, although extending to the tropics on one side
and to the arctic regions on the other. The white type, originating in
the north temperate zone, has spread over the whole world. They have
attained the highest culture, profess the purest forms of monotheistic
religion, and have brought all the people of the black type and many
of those of the yellow under their domination.

The contrast between the yellow and white types has been softened by
the remarkable development of the Japanese following the assimilation
of western methods.

The actual number of human inhabitants in the world has been
calculated as follows:

By Continents.[46]

Asia 875,000,000
Europe 392,000,000
Africa 170,000,000
America 143,000,000
Australia and Polynesia 7,000,000
-------------
Total 1,587,000,000

By Race.[47]

White (Caucasic) 770,000,000
Yellow (Mong.) 540,000,000
Black (Ethiopic) 175,000,000
Red (American) 22,000,000
-------------
Total 1,507,000,000

In round numbers the population of the world is about 1,600,000,000,
and, according to an estimate by Ravenstein,[48] the maximum
population which it will be possible for the earth to maintain is 6000
millions, a number which, if the average rate of increase in 1891
continued, would be reached within 200 years.

While highly civilized communities are able to evade many of the
restrictions of environment, to overcome the barriers to
intercommunication interposed by land or sea, to counteract the
adverse influence of climate, and by the development of trade even to
inhabit countries which cannot yield a food-supply, the mass of
mankind is still completely under the control of those conditions
which in the past determined the distribution and the mode of life of
the whole human race.

Influence of environment on man.

In tropical forests primitive tribes depend on the collection of wild
fruits, and in a minor degree on the chase of wild animals, for their
food. Clothing is unnecessary; hence there is little occasion for
exercising the mental faculties beyond the sense of perception to
avoid enemies, or the inventive arts beyond what is required for the
simplest weapons and the most primitive fortifications. When the
pursuit of game becomes the chief occupation of a people there is of
necessity a higher development of courage, skill, powers of
observation and invention; and these qualities are still further
enhanced in predatory tribes who take by force the food, clothing and
other property prepared or collected by a feebler people. The
fruit-eating savage cannot stray beyond his woods which bound his life
as the water bounds that of a fish; the hunter is free to live on the
margin of forests or in open country, while the robber or warrior from
some natural stronghold of the mountains sweeps over the adjacent
plains and carries his raids into distant lands. Wide grassy steppes
lead to the organization of the people as nomads whose wealth consists
in flocks and herds, and their dwellings are tents. The nomad not only
domesticates and turns to his own use the gentler and more powerful
animals, such as sheep, cattle, horses, camels, but even turns some
predatory creatures, like the dog, into a means of defending their
natural prey. They hunt the beasts of prey destructive to their
flocks, and form armed bands for protection against marauders or for
purposes of aggression on weaker sedentary neighbours. On the fertile
low grounds along the margins of rivers or in clearings of forests,
agricultural communities naturally take their rise, dwelling in
villages and cultivating the wild grains, which by careful nurture and
selection have been turned into rich cereals. The agriculturist as a
rule is rooted to the soil. The land he tills he holds, and acquires a
closer connexion with a particular patch of ground than either the
hunter or the herdsman. In the temperate zone, where the seasons are
sharply contrasted, but follow each other with regularity, foresight
and self-denial were fostered, because if men did not exercise these
qualities seed-time or harvest might pass into lost opportunities and
the tribes would suffer. The more extreme climates of arid regions on
the margins of the tropics, by the unpredictable succession of
droughts and floods, confound the prevision of uninstructed people,
and make prudence and industry qualities too uncertain in their
results to be worth cultivating. Thus the civilization of agricultural
peoples of the temperate zone grew rapidly, yet in each community a
special type arose adapted to the soil, the crop and the climate. On
the seashore fishing naturally became a means of livelihood, and
dwellers by the sea, in virtue of the dangers to which they are
exposed from storm and unseaworthy craft, are stimulated to a higher
degree of foresight, quicker observation, prompter decision and more
energetic action in emergencies than those who live inland. The
building and handling of vessels also, and the utilization of such
uncontrollable powers of nature as wind and tide, helped forward
mechanical invention. To every type of coast there may be related a
special type of occupation and even of character; the deep and gloomy
fjord, backed by almost impassable mountains, bred bold mariners whose
only outlet for enterprise was seawards towards other lands--the
_viks_ created the vikings. On the gently sloping margin of the
estuary of a great river a view of tranquil inland life was equally
presented to the shore-dweller, and the ocean did not present the only
prospect of a career. Finally the mountain valley, with its patches of
cultivable soil on the alluvial fans of tributary torrents, its narrow
pastures on the uplands only left clear of snow in summer, its
intensified extremes of climates and its isolation, almost equal to
that of an island, has in all countries produced a special type of
brave and hardy people, whose utmost effort may bring them comfort,
but not wealth, by honest toil, who know little of the outer world,
and to whom the natural outlet for ambition is marauding on the
fertile plains. The highlander and viking, products of the valleys
raised high amid the mountains or half-drowned in the sea, are
everywhere of kindred spirit.

It is in some such manner as these that the natural conditions of
regions, which must be conformed to by prudence and utilized by labour
to yield shelter and food, have led to the growth of peoples differing
in their ways of life, thought and speech. The initial differences so
produced are confirmed and perpetuated by the same barriers which
divide the faunal or floral regions, the sea, mountains, deserts and
the like, and much of the course of past history and present politics
becomes clear when the combined results of differing race and
differing environment are taken into account.[49]

Density of population.

The specialization which accompanies the division of labour has
important geographical consequences, for it necessitates communication
between communities and the interchange of their products. Trade
makes it possible to work mineral resources in localities where food
can only be grown with great difficulty and expense, or which are even
totally barren and waterless, entirely dependent on supplies from
distant sources.

The population which can be permanently supported by a given area of
land differs greatly according to the nature of the resources and the
requirements of the people. Pastoral communities are always scattered
very thinly over large areas; agricultural populations may be almost
equally sparse where advanced methods of agriculture and labour-saving
machinery are employed; but where a frugal people are situated on a
fertile and inexhaustible soil, such as the deltas and river plains of
Egypt, India and China, an enormous population may be supported on a
small area. In most cases, however, a very dense population can only
be maintained in regions where mineral resources have fixed the site
of great manufacturing industries. The maximum density of population
which a given region can support is very difficult to determine; it
depends partly on the race and standard of culture of the people,
partly on the nature and origin of the resources on which they depend,
partly on the artificial burdens imposed and very largely on the
climate. Density of population is measured by the average number of
people residing on a unit of area; but in order to compare one part of
the world with another the average should, strictly speaking, be taken
for regions of equal size or of equal population; and the portions of
the country which are permanently uninhabitable ought to be excluded
from the calculation.[50] Considering the average density of
population within the political limits of countries, the following
list is of some value; the figures for a few smaller divisions of
large countries are added (in brackets) for comparison:

_Average Population on 1 sq. m._ (_For 1900 or 1901._)

+--------------------+---------+-------------------+---------+
| Country. | Density | Country. | Density |
| | of pop. | | of pop. |
+--------------------+---------+-------------------+---------+
| (Saxony) | 743* | Ceylon | 141** |
| Belgium | 589* | Greece | 97 |
| Java | 568** | European Turkey | 90 |
| (England and Wales)| 558 | Spain | 97 |
| (Bengal) | 495** | European Russia | 55** |
| Holland | 436 | Sweden | 30 |
| United Kingdom | 344 | United States | 25 |
| Japan | 317 | Mexico | 18 |
| Italy | 293 | Norway | 18 |
| China proper | 270** | Persia | 15 |
| German Empire | 270 | New Zealand | 7 |
| Austria | 226 | Argentina | 5 |
| Switzerland | 207 | Brazil | 4.5 |
| France | 188 | Eastern States of | |
| Indian Empire | 167** | Australia | 3 |
| Denmark | 160** | Dominion of Canada| 1.5 |
| Hungary | 154** | Siberia | 1 |
| Portugal | 146 | West Australia | 0.2 |
+--------------------+---------+-------------------+---------+
* Almost exclusively industrial.
** Almost exclusively agricultural.

Migration.

The movement of people from one place to another without the immediate
intention of returning is known as migration, and according to its
origin it may be classed as centrifugal (directed _from_ a particular
area) and centripetal (directed _towards_ a particular area).
Centrifugal migration is usually a matter of compulsion; it may be
necessitated by natural causes, such as a change of climate leading to
the withering of pastures or destruction of agricultural land, to
inundation, earthquake, pestilence or to an excess of population over
means of support; or to artificial causes, such as the wholesale
deportation of a conquered people; or to political or religious
persecution. In any case the people are driven out by some adverse
change; and when the urgency is great they may require to drive out in
turn weaker people who occupy a desirable territory, thus propagating
the wave of migration, the direction of which is guided by the forms
of the land into inevitable channels. Many of the great historic
movements of peoples were doubtless due to the gradual change of
geographical or climatic conditions; and the slow desiccation of
Central Asia has been plausibly suggested as the real cause of the
peopling of modern Europe and of the medieval wars of the Old World,
the theatres of which were critical points on the great natural lines
of communication between east and west.

In the case of centripetal migrations people flock to some particular
place where exceptionally favourable conditions have been found to
exist. The rushes to gold-fields and diamond-fields are typical
instances; the growth of towns on coal-fields and near other sources
of power, and the rapid settlement of such rich agricultural districts
as the wheat-lands of the American prairies and great plains are other
examples.

There is, however, a tendency for people to remain rooted to the land
of their birth, when not compelled or induced by powerful external
causes to seek a new home.

Political geography.

Thus arises the spirit of patriotism, a product of purely geographical
conditions, thereby differing from the sentiment of loyalty, which is
of racial origin. Where race and soil conspire to evoke both loyalty
and patriotism in a people, the moral qualities of a great and
permanent nation are secured. It is noticeable that the patriotic
spirit is strongest in those places where people are brought most
intimately into relation with the land; dwellers in the mountain or by
the sea, and, above all, the people of rugged coasts and mountainous
archipelagoes, have always been renowned for love of country, while
the inhabitants of fertile plains and trading communities are
frequently less strongly attached to their own land.

Amongst nomads the tribe is the unit of government, the political bond
is personal, and there is no definite territorial association of the
people, who may be loyal but cannot be patriotic. The idea of a
country arises only when a nation, either homogeneous or composed of
several races, establishes itself in a region the boundaries of which
may be defined and defended against aggression from without. Political
geography takes account of the partition of the earth amongst
organized communities, dealing with the relation of races to regions,
and of nations to countries, and considering the conditions of
territorial equilibrium and instability.

Boundaries.

The definition of boundaries and their delimitation is one of the most
important parts of political geography. Natural boundaries are always
the most definite and the strongest, lending themselves most readily
to defence against aggression. The sea is the most effective of all,
and an island state is recognized as the most stable. Next in
importance comes a mountain range, but here there is often difficulty
as to the definition of the actual crest-line, and mountain ranges
being broad regions, it may happen that a small independent state,
like Switzerland or Andorra, occupies the mountain valleys between two
or more great countries. Rivers do not form effective international
boundaries, although between dependent self-governing communities they
are convenient lines of demarcation. A desert, or a belt of country
left purposely without inhabitants, like the mark, marches or
debatable lands of the middle ages, was once a common means of
separating nations which nourished hereditary grievances. The
"buffer-state" of modern diplomacy is of the same ineffectual type. A
less definite though very practical boundary is that formed by the
meeting-line of two languages, or the districts inhabited by two
races. The line of fortresses protecting Austria from Italy lies in
some places well back from the political boundary, but just inside the
linguistic frontier, so as to separate the German and Italian races
occupying Austrian territory. Arbitrary lines, either traced from
point to point and marked by posts on the ground, or defined as
portions of meridians and parallels, are now the most common type of
boundaries fixed by treaty. In Europe and Asia frontiers are usually
strongly fortified and strictly watched in times of peace as well as
during war. In South America strictly defined boundaries are still the
exception, and the claims of neighbouring nations have very frequently
given rise to war, though now more commonly to arbitration.[51]

Forms of government.

The modes of government amongst civilized peoples have little
influence on political geography; some republics are as arbitrary and
exacting in their frontier regulations as some absolute monarchies. It
is, however, to be noticed that absolute monarchies are confined to
the east of Europe and to Asia, Japan being the only established
constitutional monarchy east of the Carpathians. Limited monarchies
are (with the exception of Japan) peculiar to Europe, and in these the
degree of democratic control may be said to diminish as one passes
eastwards from the United Kingdom. Republics, although represented in
Europe, are the peculiar form of government of America and are unknown
in Asia.

The forms of government of colonies present a series of transitional
types from the autocratic administration of a governor appointed by
the home government to complete democratic self-government. The latter
occurs only in the temperate possessions of the British empire, in
which there is no great preponderance of a coloured native population.
New colonial forms have been developed during the partition of Africa
amongst European powers, the sphere of influence being especially
worthy of notice. This is a vaguer form of control than a
protectorate, and frequently amounts merely to an agreement amongst
civilized powers to respect the right of one of their number to
exercise government within a certain area, if it should decide to do
so at any future time.

The central governments of all civilized countries concerned with
external relations are closely similar in their modes of action, but
the internal administration may be very varied. In this respect a
country is either centralized, like the United Kingdom or France, or
federated of distinct self-governing units like Germany (where the
units include kingdoms, at least three minor types of monarchies,
municipalities and a crown land under a nominated governor), or the
United States, where the units are democratic republics. The ultimate
cause of the predominant form of federal government may be the
geographical diversity of the country, as in the cantons occupying the
once isolated mountain valleys of Switzerland, the racial diversity of
the people, as in Austria-Hungary, or merely political expediency, as
in republics of the American type.

The minor subdivisions into provinces, counties and parishes, or
analogous areas, may also be related in many cases to natural features
or racial differences perpetuated by historical causes. The
territorial divisions and subdivisions often survive the conditions
which led to their origin; hence the study of political geography is
allied to history as closely as the study of physical geography is
allied to geology, and for the same reason.

Towns.

The aggregation of population in towns was at one time mainly brought
about by the necessity for defence, a fact indicated by the defensive
sites of many old towns. In later times, towns have been more often
founded in proximity to valuable mineral resources, and at critical
points or nodes on lines of communication. These are places where the
mode of travelling or of transport is changed, such as seaports, river
ports and railway termini, or natural resting-places, such as a ford,
the foot of a steep ascent on a road, the entrance of a valley leading
up from a plain into the mountains, or a crossing-place of roads or
railways.[52] The existence of a good natural harbour is often
sufficient to give origin to a town and to fix one end of a line of
land communication.

Lines of communication.

In countries of uniform surface or faint relief, roads and railways
may be constructed in any direction without regard to the
configuration. In places where the low ground is marshy, roads and
railways often follow the ridge-lines of hills, or, as in Finland, the
old glacial eskers, which run parallel to the shore. Wherever the
relief of the land is pronounced, roads and railways are obliged to
occupy the lowest ground winding along the valleys of rivers and
through passes in the mountains. In exceptional cases obstructions
which it would be impossible or too costly to turn are overcome by a
bridge or tunnel, the magnitude of such works increasing with the
growth of engineering skill and financial enterprise. Similarly the
obstructions offered to water communication by interruption through
land or shallows are overcome by cutting canals or dredging out
channels. The economy and success of most lines of communication
depend on following as far as possible existing natural lines and
utilizing existing natural sources of power.[53]

Commercial geography.

Commercial geography may be defined as the description of the earth's
surface with special reference to the discovery, production, transport
and exchange of commodities. The transport concerns land routes and
sea routes, the latter being the more important. While steam has been
said to make a ship independent of wind and tide, it is still true
that a long voyage even by steam must be planned so as to encounter
the least resistance possible from prevailing winds and permanent
currents, and this involves the application of oceanographical and
meteorological knowledge. The older navigation by utilizing the power
of the wind demands a very intimate knowledge of these conditions, and
it is probable that a revival of sailing ships may in the present
century vastly increase the importance of the study of maritime
meteorology.

The discovery and production of commodities require a knowledge of the
distribution of geological formations for mineral products, of the
natural distribution, life-conditions and cultivation or breeding of
plants and animals and of the labour market. Attention must also be
paid to the artificial restrictions of political geography, to the
legislative restrictions bearing on labour and trade as imposed in
different countries, and, above all, to the incessant fluctuations of
the economic conditions of supply and demand and the combinations of
capitalists or workers which affect the market.[54] The term "applied
geography" has been employed to designate commercial geography, the
fact being that every aspect of scientific geography may be applied to
practical purposes, including the purposes of trade. But apart from
the applied science, there is an aspect of pure geography which
concerns the theory of the relation of economics to the surface of the
earth.

Conclusion.

It will be seen that as each successive aspect of geographical science
is considered in its natural sequence the conditions become more
numerous, complex, variable and practically important. From the
underlying abstract mathematical considerations all through the
superimposed physical, biological, anthropological, political and
commercial development of the subject runs the determining control
exercised by crust-forms acting directly or indirectly on mobile
distributions; and this is the essential principle of geography.
(H. R. M.)

FOOTNOTES:

[1] A concise sketch of the whole history of geographical method or
theory as distinguished from the history of geographical discovery
(see later section of this article) is only to be found in the
introduction to H. Wagner's _Lehrbuch der Geographie_, vol. i.
(Leipzig, 1900), which is in every way the most complete treatise on
the principles of geography.

[2] _History of Ancient Geography_ (Cambridge, 1897), p. 70.

[3] See J.L. Myres, "An Attempt to reconstruct the Maps used by
Herodotus," _Geographical Journal_, viii. (1896), p. 605.

[4] _Geschichte der wissenschaftlichen Erdkunde der Griechen_
(Leipzig, 1891), Abt. 3, p. 60.

[5] Bunbury's _History of Ancient Geography_ (2 vols., London, 1879),
Muller's _Geographi Graeci minores_ (2 vols., Paris, 1855, 1861) and
Berger's _Geschichte der wissenschaftlichen Erdkunde der Griechen_ (4
vols., Leipzig, 1887-1893) are standard authorities on the Greek
geographers.

[6] The period of the early middle ages is dealt with in Beazley's
_Dawn of Modern Geography_ (London; part i., 1897; part ii., 1901;
part iii., 1906); see also Winstedt, _Cosmos Indicopleustes_ (1910).

[7] From translator's preface to the English version by Mr Dugdale
(1733), entitled _A Complete System of General Geography_, revised by
Dr Peter Shaw (London, 1756).

[8] Printed in _Schriften zur physischen Geographie_, vol. vi. of
Schubert's edition of the collected works of Kant (Leipzig, 1839).
First published with notes by Rink in 1802.

[9] _History of Civilization_, vol. i. (1857).

[10] See H.J. Mackinder in _British Association Report_ (Ipswich),
1895, p. 738, for a summary of German opinion, which has been
expressed by many writers in a somewhat voluminous literature.

[11] H. Wagner's year-book, _Geographische Jahrbuch_, published at
Gotha, is the best systematic record of the progress of geography in
all departments; and Haack's _Geographen Kalender_, also published
annually at Gotha, gives complete lists of the geographical societies
and geographers of the world.

[12] This phrase is old, appearing in one of the earliest English
works on geography, William Cuningham's _Cosmographical Glasse
conteinyng the pleasant Principles of Cosmographie, Geographie,
Hydrographie or Navigation_ (London, 1559).

[13] See also S. Gunther, _Handbuch der mathematischen Geographie_
(Stuttgart, 1890).

[14] "On the Height of the Land and the Depth of the Ocean," _Scot.
Geog. Mag._ iv. (1888), p. 1. Estimates had been made previously by
Humboldt, De Lapparent, H. Wagner, and subsequently by Penck and
Heiderich, and for the oceans by Karstens.

[15] _Petermanns Mitteilungen_, xxv. (1889), p. 17.

[16] _Proc. Roy. Soc. Edin._ xvii. (1890) p. 185.

[17] _Comptes rendus Acad. Sci._ (Paris, 1890), vol. iii. p. 994.

[18] "Areal und mittlere Erhebung der Landflachen sowie der
Erdkruste" in Gerland's _Beitrage zur Geophysik_, ii. (1895) p. 667.
See also _Nature_, 54 (1896), p. 112.

[19] _Petermanns Mitteilungen_, xxxv. (1889) p. 19.

[20] The areas of the continental shelf and lowlands are
approximately equal, and it is an interesting circumstance that,
taken as a whole, the actual coast-line comes just midway on the most
nearly level belt of the earth's surface, excepting the ocean floor.
The configuration of the continental slope has been treated in detail
by Nansen in _Scientific Results of Norwegian North Polar
Expedition_, vol. iv. (1904), where full references to the literature
of the subject will be found.

[21] _British Association Report_ (Edinburgh, 1892), p. 699.

[22] _Das Antlitz der Erde_ (4 vols., Leipzig, 1885, 1888, 1901).
Translated under the editorship of E. de Margerie, with much
additional matter, as _La Face de la terre_, vols. i. and ii. (Paris,
1897, 1900), and into English by Dr Hertha Sollas as _The Face of the
Earth_, vols. i. and ii. (Oxford, 1904, 1906).

[23] Elie de Beaumont, _Notice sur les systemes de montagnes_ (3
vols., Paris, 1852).

[24] _Vestiges of the Molten Globe_ (London, 1875).

[25] See J.W. Gregory, "The Plan of the Earth and its Causes," _Geog.
Journal_, xiii. (1899) p. 225; Lord Avebury, _ibid._ xv. (1900) p.
46; Marcel Bertrand, "Deformation tetraedrique de la terre et
deplacement du pole," _Comptes rendus Acad. Sci._ (Paris, 1900), vol.
cxxx. p. 449; and A. de Lapparent, _ibid._ p. 614.

[26] See A.E.H. Love, "Gravitational Stability of the Earth," _Phil.
Trans._ ser. A. vol. ccvii. (1907) p. 171.

[27] _Rumpf_, in German, the language in which this distinction was
first made.

[28] _Lehrbuch der Geographie_ (Hanover and Leipzig, 1900), Bd. i. S.
245, 249.

[29] See, for example, F.G. Hahn's _Insel-Studien_ (Leipzig, 1883).

[30] See _Geographical Journal_, xxii. (1903) pp. 191-194.

[31] The most important works on the classification of land forms are
F. von Richthofen, _Fuhrer fur Forschungsreisende_ (Berlin, 1886); G.
de la Noe and E. de Margerie, _Les Formes du terrain_ (Paris, 1888);
and above all A. Penck, _Morphologie der Erdoberflache_ (2 vols.,
Stuttgart, 1894). Compare also A. de Lapparent, _Lecons de geographie
physique_ (2nd ed., Paris, 1898), and W.M. Davis, _Physical
Geography_ (Boston, 1899).

[32] "Geomorphologie als genetische Wissenschaft," in _Report of
Sixth International Geog. Congress_ (London, 1895), p. 735 (English
Abstract, p. 748).

[33] On this subject see J. Geikie, _Earth Sculpture_ (London, 1898);
J.E. Marr, _The Scientific Study of Scenery_ (London, 1900); Sir A.
Geikie, _The Scenery and Geology of Scotland_ (London, 2nd ed.,
1887); Lord Avebury (Sir J. Lubbock), _The Scenery of Switzerland_
(London, 1896) and _The Scenery of England_ (London, 1902).

[34] Some geographers distinguish a mountain from a hill by origin;
thus Professor Seeley says "a mountain implies elevation and a hill
implies denudation, but the external forms of both are often
identical." _Report VI. Int. Geog. Congress_ (London, 1895), p. 751.

[35] "Mountains," in _Scot. Geog. Mag._ ii. (1896) p. 145.

[36] _Fuhrer fur Forschungsreisende_, pp. 652-685.

[37] See, for a summary of river-action, A. Phillipson, _Studien uber
Wasserscheiden_ (Leipzig, 1886); also I.C. Russell, _River
Development_, (London, 1898) (published as _The Rivers of North
America_, New York, 1898).

[38] W.M. Davis, "The Geographical Cycle," _Geog. Journ._ xiv. (1899)
p. 484.

[39] A. Penck, "Potamology as a Branch of Physical Geography," _Geog.
Journ._ x. (1897) p. 619.

[40] See, for instance, E. Wisotzki, _Hauptfluss und Nebenfluss_
(Stettin, 1889). For practical studies see official reports on the
Mississippi, Rhine, Seine, Elbe and other great rivers.

[41] F.A. Forel, _Handbuch der Seenkunde: allgemeine Limnologie_
(Stuttgart, 1901); F.A. Forel, "La Limnologie, branche de la
geographie," _Report VI. Int. Geog. Congress_ (London, 1895), p. 593;
also _Le Leman_ (2 vols., Lausanne, 1892, 1894); H. Lullies, "Studien
uber Seen," _Jubilaumsschrift der Albertus-Universitat_ (Konigsberg,
1894); and G.R. Credner, "Die Reliktenseen," _Petermanns
Mitteilungen_, Erganzungshefte 86 and 89 (Gotha., 1887, 1888).

[42] J. Murray, "Drainage Areas of the Continents," _Scot. Geog.
Mag._ ii. (1886) p. 548.

[43] Wagner, _Lehrbuch der Geographie_ (1900), i. 586.

[44] For details, see A.R. Wallace, _Geographical Distribution of
Animals and Island Life_; A. Heilprin, _Geographical and Geological
Distribution of Animals_ (1887); O. Drude, _Handbuch der
Pflanzengeographie_; A. Engler, _Entwickelungsgeschichte der
Pflanzenwelt_; also Beddard, _Zoogeography_ (Cambridge, 1895); and
Sclater, _The Geography of Mammals_ (London, 1899).

[45] See particularly A. de Lapparent, _Traite de geologie_ (4th ed.,
Paris, 1900).

[46] Estimate for 1900. H. Wagner, _Lehrbuch der Geographie_, i. P.
658.

[47] Estimate for year not stated. A.H. Keane in _International
Geography_, p. 108.

[48] In _Proc. R. G. S._ xiii. (1891) p. 27.

[49] On the influence of land on people see Shaler, _Nature and Man
in America_ (New York and London, 1892); and Ellen C. Semple's
_American History and its Geographic Conditions_ (Boston, 1903).

[50] See maps of density of population in Bartholomew's great
large-scale atlases, _Atlas of Scotland_ and _Atlas of England_.

[51] For the history of territorial changes in Europe, see Freeman,
_Historical Geography of Europe_, edited by Bury (Oxford), 1903; and
for the official definition of existing boundaries, see Hertslet,
_The Map of Europe by Treaty_ (4 vols., London, 1875, 1891); _The Map
of Africa by Treaty_ (3 vols., London, 1896). Also Lord Curzon's
Oxford address on _Frontiers_ (1907).