Influences of Geographic Environment Part 60

[Sidenote: Man as part of the mobile envelope of the earth.]

The important characteristic of plains is their power to facilitate every phase of historical movement; that of mountains is their power to r.e.t.a.r.d, arrest, or deflect it. Man, as part of the mobile envelope of the earth, like air and water feels always the pull of gravity. From this he can never fully emanc.i.p.ate himself. By an output of energy he may climb the steepest slope, but with every upward step the ascent becomes more difficult, owing to the diminution of warmth and air and the increasing tax upon the heart.[1186] Maintenance of life in high alt.i.tudes is always a struggle. The decrease of food resources from lower to higher levels makes the pa.s.sage of a mountain system an ordeal for every migrating people or marching army that has to live off the country which it traverses. Mountains therefore repel population by their inaccessibility and also by their harsh conditions of life, while the lowlands attract it, both in migration and settlement. Historical movement, when forced into the upheaved areas of the earth, avoids the ridges and peaks, seeks the valleys and pa.s.ses, where communication with the lowlands is easiest.

[Sidenote: Inaccessibility of mountains.]

High ma.s.sive mountain systems present the most effective barriers which man meets on the land surface of the earth. To the spread of population they offer a resistance which long serves to exclude settlers. The difficulty of making roads up steep, rocky slopes and through the forests usually covering their rain-drenched sides, is deterrent enough; but in addition to this, general infertility, paucity of arable land, harsh climatic conditions, and the practical lack of communication with the outside world offer scant basis for subsistence. Hence, as a rule, only when pressure of population in the lowlands becomes too great under prevailing economic methods, do clearings and cabins begin to creep up the slopes. Mountains are always regions of late occupation. Even in the Stone Age, we find the long-headed race of Mediterranean stock, who originally populated Europe, distributed over the continent close up to the foot of the high Alps, but not in the mountains themselves, and only scantily represented in the Auvergne Plateau of France. The inhospitable highlands of Switzerland, the German Alps, and the Auvergne received their first population later when the Alpine race began to occupy western Europe.[1187] The _Mittelgebirge_ of Germany were not settled till the Middle Ages. In the United States, the flood of population had spread westward by 1840 to the ninety-fifth meridian and the north-south course of the Missouri River; but out of this sea of settlement the Adirondack Mountains, a few scattered spots in the Appalachians, and the Ozark Highlands rose as so many islands of uninhabited wilderness, and they remain to-day areas of spa.r.s.er population. In 1800, the "bare spots" in the eastern mountains were more p.r.o.nounced. [See map page 156.] Great stretches of the Rocky Mountains, of the Laurentian Highlands of Canada, like smaller patches in the Scandinavian and Swiss Alps, are practically uninhabited.

[Sidenote: Mountains as transit regions.]

Mountain regions, like deserts and seas, become mere transit districts, which man traverses as quickly as possible. Hence they often lie as great inert areas in the midst of active historical lands, and first appear upon the historical stage in minor roles, when they are wanted by the plains people as a pa.s.sway to desirable regions beyond. Then, as a rule, only their transit routes are secured, while the less accessible regions are ignored. Caesar makes no mention of the Alps, except to state that he has crossed them, until some of the mountain tribes try to block the pa.s.sage of Roman merchants or armies; then they become important enough to be conquered. It was not till after the Cimbri in 102 B.C.

invaded Italy by the Brenner route, that the Romans realized the value of Rhaetia (Tyrol) as a thoroughfare from Italy to Germany, and began its conquest in 36 B.C. This was the same value which the Tyrol so long had for the old German Empire and later for Austria,--merely to secure connection with the Po Valley. The need of land communication with the Rhone Valley led the Romans to attack the Salyes, who inhabited the Maritime Alps, and after eighty years of war to force from them the concession of a narrow transit strip, twelve stadia or one and a half miles wide, for the purpose of making a road to Ma.s.silia.[1188] The necessity of controlling such transit lands has drawn British India into the occupation of mountain Baluchistan, Kashmir and Sikkim, just as it has caused the highlands of Afghanistan to figure actively in the expansion policy of both India and Russia. The conquest of such transit lands has always been attended by road building, from the construction of the Roman highway through the Brenner Pa.s.s to the modern Russian military road through the Pa.s.s of Dariel across the Caucasus, and the yet more recent Indian railroad to Darjeeling, with the highway extension beyond to the Tibetan frontier through Himalayan Sikkim.

Such mountain regions attain independent historical importance when their population increases enough to form the nucleus of a state, and to acquire additional territory about the highland base either by conquest or voluntary union, while they utilize their naturally protected location and their power to grant safe transit to their allies, as means to secure their political autonomy. Therefore to mountain regions so often falls the role of buffer states. Such were medieval Burgundy and modern Savoy, which occupied part of the same territory, Navarre which in the late Middle Ages controlled the important pa.s.sway around the western end of the Pyrenees, and Switzerland which commands the pa.s.ses of the central Alps. The position of such mountain states is, however, always fraught with danger, owing to the weakness inherent in their small area and yet smaller allowance of productive soil, to their diverse ethnic elements, and the forces working against political consolidation in their deeply dissected surface. Political solidarity has a hard, slow birth in the mountains.

[Sidenote: Transition forms of relief between highlands and lowlands.]

In view of the barrier character of mountains, a fact of immense importance to the distribution of man and his activities is the rarity of abrupt, ungraded forms of relief on the earth's surface. The physiographic cause lies in the elasticity of the earth's crust and the leveling effect of weathering and denudation. Everywhere mountains are worn down and rounded off, while valleys broaden and fill up to shallow trough outlines. Transition forms of relief abound. Human intercourse meets therefore few absolute barriers on the land; but these few reveal the obstacles to historical movement in perpendicular reliefs. The mile-high walls of the Grand Canon of the Colorado are an insuperable obstacle to intercourse for a stretch of three hundred miles. The glacier-crowned ridge of the Bernese Alps is crossed by no wagon road between the Grimsel Pa.s.s and the upper Rhone highway around their western end, a distance of 100 kilometers (62 miles). The Pennine Alps have no pa.s.s between the Great St. Bernard and the Simplon, a distance of 90 kilometers (54 miles).

[Sidenote: Importance of transition slopes.]

Gentle transition slopes or terrace lands facilitate almost everywhere access to the lowest, most habitable and therefore, from the human standpoint, most important section of mountains. They combine the ease of intercourse characteristic of plains with many advantages of the mountains, and especially in warm climates they unite in a narrow zone both tropical and temperate vegetation. The human value of these transition slopes holds equally of single hills, ma.s.sive mountain systems, and continental reliefs. The earth as a whole owes much of its habitability to these gently graded slopes. Continents and countries in which they are meagerly developed suffer from difficulty of intercourse, r.e.t.a.r.ded development and poverty of the choicest habitable areas. This is one disadvantage of South Africa, emphasized farther by a poor coastline. The Pacific face of Australia would gain vastly in historical importance, if the drop from the highlands to the ocean were stretched out into a broad slope, like that which links our Atlantic coastal plain with the Appalachian highlands. There each river valley shows three characteristic anthropo-geographical sub-divisions--the active seaports and tide-water tillage of its lower course, the contrasted agriculture of its hilly course, the upland farms, waterpower industries and mines of its headstream valleys, each landscape giving its population distinctive characteristics. The same natural features, with the same effect upon human activities and population, appear in the long seaward slopes of France, Germany and northern Italy.

[Sidenote: Piedmont belts as boundary zones.]

At the base of the mountains themselves, where the bold relief begins, is always a piedmont zone of hilly surface but gentler grade, at whose inner or upland edge every phase of the historical movement receives a marked check. Here is a typical geographical boundary, physical and human. It s.h.i.+fts slightly in different periods, according to the growing density of population in the plains below and improved technique in industry and road-making. It is often both an ethnic and cultural boundary, because at the rim of the mountains the geologic and economic character of the country changes.[1189] The expanding peoples of the plains spread over the piedmont so far as it offers familiar and comparatively favorable geographic conditions, scatter their settlements along the base of the mountains, and here fix their political frontier for a time, though later they may advance it to the crest of the ridge, in order to secure a more scientific boundary. The civilized population of the broad Indus Valley spread westward up the western highlands, only so far as the shelving slopes of the clay and conglomerate foothills, which const.i.tute the piedmont of the Suleiman and Kirthar Mountains, afforded conditions for their crops. Thus from the Arabian Sea for 600 miles north to the Gomal River, the political frontier of India was defined by the line of relief dividing the limestone mountains from the alluvial plain, the marauding Baluch and Afghan hill tribes from the patient farmers of the Sind.[1190] This line remained the border of India from pre-British days till the recent annexation of Baluchistan.

These piedmont boundaries are most clearly defined in point of race and civilization, where superior peoples from the lowlands are found expanding at the cost of r.e.t.a.r.ded mountain folk. Romans and Rhaetians once met along a line skirting the foot of the eastern Alps, as Russians to-day along the base of the Caucasus adjoin the territories of the heterogeneous tribes occupying that mountain area.[1191] [See map page 225.] The plains-loving Magyars of Hungary have pushed up to the rim of mountainous Siebenburgen or Transylvania from Arad on the Maros River to Sziget on the upper Theiss, while the highland region has a predominant Roumanian population. A clearly defined linguistic and cultural boundary of Indo-Aryan speech and religion, both Hindu and Mohammedan, follows the piedmont edges of the Brahmaputra Valley, and separates the lowland inhabitants from the pagans of Tibeto-Burman speech occupying the Himalayan slope to the north and the Khasia Mountains to the south. The highland race is Mongoloid, while the Bengali of an Aryan, Dravidian and Mongoloid blend fill the river plain.[1192] Such piedmont boundary lines tend to blur into bands or zones of ethnic intermixture and cultural a.s.similation. The western Himalayan foothills show the blend of Mongoloid and Aryan stocks, where the vigorous Rajputs of the plains have encroached upon the mountaineer's land.[1193] Of almost every mountain folk it can be a.s.sumed that they once occupied their highlands to the outermost rim of the piedmont, and retired to the inner rim of this intermediary slope only under compulsion from without.

[Sidenote: Density of population in piedmont belts.]

The piedmont boundary also divides two areas of contrasted density of population. Mountain regions are, as a rule, more spa.r.s.ely settled than plains. The piedmont is normally a transition region in this respect; but where high mountains rise as climatic islands of adequate water supply out of desert and steppes, they concentrate on their lower slopes all the sedentary population, making their piedmonts zones of greatest density. Low mountains in arid regions become centers of population; here their barrier nature vanishes. In the Sudanese state of Darfur, the Marra Mountains are the district best watered and most thickly populated. Nowhere higher than 6000 feet (1850 meters), they afford running water at 4000 feet elevation and water pools in the sandy beds of their wadis at 3200 feet. Below this, water disappears from the surface, and can be found only in wells whose depth and scarcity increase with distance from the central mountains.[1194] The neighboring kingdom of Wadai shows similar conditions and effects.[1195] In the heart of Australia, where utter desert reigns, the Macdonnell Ranges form the nucleus of the northern area occupied by the Arunta tribe of natives; farther north the Murchison Range, usually abounding in water-holes, is the center and stronghold of the Warramunga tribe.[1196]

Mineral wealth or waterpower in the mountains serves to collect an urban and industrial population along their rim, as we see it about the base of the Erz Mountains in Saxony, the Riesen range in Silesia, the coal-bearing Pennine Mountains of northwestern England, and the highlands of southern Wales, all which piedmont zones show a density of over 150 to the square kilometer (385 to the square mile). Hence the original Swiss Confederation, which included only the mountain cantons of Schwyz, Uri and Unterwalden, was greatly strengthened by the accession of the piedmont cantons of Lucerne, Zurich, Zug and Bern in the early fourteenth century, as later by St. Gall, Aargau and Geneva.

These marginal cantons to-day show a density of population exceeding 385 to the square mile, and rising to 1356 in the canton of Geneva.

[Sidenote: Piedmont towns and roads.]

Piedmont belts tend strongly towards urban development, even where rural settlement is spa.r.s.e. Sparsity of population and paucity of towns within the mountains cause main of traffic to keep outside the highlands, but close enough to their base to tap their trade at every valley outlet. On the alluvial fans or plains of these valley outlets, where mountain and piedmont road intersect, towns grow up. Some of them develop into cities, when they command transverse routes of communication quite across the highlands. The ancient _Via Aemilia_ traced the northern base of the Apennines from Ariminum on the Adriatic to Dertona at the foot of the Ligurian range back of Genoa, and connected a long line of Roman colonies. The modern railroad follows almost exactly the course of the old Roman road,[1197] while a transverse line southward across the Apennines, following an ancient highway over the Poretta Pa.s.s to the Arno Valley, has maintained the old preeminence of Bologna. A line of towns, connected by highways or railroads, according to the economic development of the section, defines the bases of the Pyrenees, Alps, Jura, Apennines, Harz, Vosges, Elburz and numerous other ranges. Along the Elburz piedmont runs the imperial road of Persia from Tabriz through Teheran to Meshed. In arid regions these piedmont roads are an unfailing feature, but their towns shrink to rural settlements, except at the junction of transmontane routes.

[Sidenote: Piedmont termini of transmontane routes.]

Piedmont cities draw their support from plain, mountain and transmontane region, relying chiefly on the fertile soil of the level country to feed their large populations. Sometimes they hug the foot of the mountains, as Bologna, Verona, Bergamo, Zurich, Denver and Pittsburg do; sometimes, like Milan, Turin, and Munich, they drop down into the plain, but keep the mountains in sight. They flourish in proportion to their local resources, in which mineral wealth is particularly important, and to the number and practicability of their transmontane connections. Hence they often receive their stamp from the mountains behind them as well as from the bordering plain. The St. Gotthard route is flanked by Lucerne on the north and Milan on the south. The Brenner has its urban outlets at Munich and Verona. Narbonne and Barcelona form the termini of the route over the eastern Pyrenees; Toulouse commands the less used central pa.s.ses, and Bayonne the western. Tiflis is situated in the great mountain trough connecting the Black Sea and the Caspian; but over the Caucasus by the Pa.s.s of Dariel come the influences which make it a Russian town. Peshawar, situated in the mountain angle of the Punjab, depends more upon the Khaibar Pa.s.s and its connections thereby with Central Asia than upon the plains of the Indus; its population, in appearance and composition nearly as much Central Asiatic as Indian, is engaged in traffic between the Punjab and the whole trans-Hindu Kush country.[1198]

Where a mountain system describes a semi-circular course, its transit routes tend to converge on the inner side, and at their foci fix the sites of busy commercial centers. Turin draws on a long series of Alpine and Apennine routes from the Pa.s.s of Giovi (1548 feet or 472 meters) leading up from Genoa on the south, to the Great St. Bernard on the north. Milan gets immense support from the St. Gotthard and Simplon railroads over the Alps, besides wagon routes over several minor pa.s.ses.

Kulm, Balkh and Kunduz in the piedmont of northern Afghanistan are fed by twenty or more pa.s.ses over the Hindu Kush and Pamir. Bukhara is the remoter focus of all these routes, and also of the valley highways of the western Tian Shan. It therefore occupies a location which would make it one of the great emporiums of the world, were it not for the expanse of desert to the west and the scantiness of its local water supply, which is tapped farther upstream for the irrigation of Samarkand. In its bazaars are found drugs, dyes and teas from India; wool, skins and dried fruit from Afghanistan; woven goods, arms, and books from Persia; and Russian wares imported by rail and caravan. English goods, which formerly came in by the Kabul route from India, have been excluded since Russia established a protectorate over the province of Bukhara. Across the highlands to the east, the cities of Kashgar and Yarkand, situated in that piedmont zone of vegetation where mountain and desert meet, are enclosed by a vast amphitheater formed by the Tian Shan, the Pamir Highlands, and the Karakorum range. Stieler's atlas marks no less than six trade routes over the pa.s.ses of these mountains from Kashgar to the headstreams of the Sir-daria and Oxus, and six from Yarkand to the Oxus and Indus. Kashgar is a meeting ground of many nationalities. To its bazaars come traders from China, India, Afghanistan, Bukhara, and Russian Turkestan.[1199] The Russian railway up the Sir-daria to Andizhan brings European goods within relatively easy reach of the Terek Davan Pa.s.s, and makes serious compet.i.tion for English wares entering by the more difficult Karakorum Pa.s.s from India.[1200]

[Sidenote: Cities of coastal piedmonts.]

Where mountains drop off into a desert, as these Central Asiatic ranges do, their piedmont cities are confined to a narrow zone between mountains and arid waste. Bordering two transit regions of scant population and through travel, they become natural outfitting points, centers of exchange rather than production. Where mountains drop off into the sea and the piedmont therefore becomes a coastal belt, again it borders two transit regions; but here the ports of the desert are replaced by maritime ports, which command the world thoroughfare of the ocean. They therefore tend to concentrate population and commerce wherever a good harbor coincides with the outlet of a transmontane route, as in Genoa and Bombay.

[Sidenote: Piedmonts as colonial or backwoods frontiers.]

Since mountains are inhospitable to every phase of the historical movement, they long remain regions of r.e.t.a.r.dation. Hence to their bordering plains they sustain the relation of young undeveloped lands, so that life in their piedmont belts tends to show for a long time all the characteristics of a new colonial frontier. The rim of the Southern Appalachians abundantly ill.u.s.trates this principle even to-day. During the westward expansion of the American people from 1830 to 1850, the eastern rim of the Rocky Mountains was dotted with trading posts like that of the Missouri Fur Company at the forks of the Missouri River, Forts Laramie and Platte on the North Fork of the Platte, Vrain's Fort and Fort Lancaster on the South Fork, Bent's Fort at the mountain exit of the Arkansas River, and Barclay's in the high Mora Valley of the upper Canadian. These posts gathered in the rich pelts which formed the one product of this highland area susceptible of bearing the cost of transportation to the far away Missouri River. Though they developed into way-stations on the overland trails, when the movement of population to California and Oregon in the forties and fifties made the Rocky Mountains a typical highland transit region, yet they long remained frontier posts.[1201] Later the abundant water supply of this piedmont district, as compared with the arid plains below, and the mineral wealth of the mountains concentrated here an agricultural and industrial population.

In Sze Chuan province of western China, the piedmont of a vast highland hinterland shows a similar development. Here the towns of Matang, Sungpan, Kuan Hsien, and even the capital Chengtu, situated in the high Min Valley at the foot of the mountains walling them in on the west, are emporiums for trade with the Tibetans, who bring hither furs, hides and wool from their plateau pastures, and musk from the musk deer on the Koko Nor plains.[1202] Just to the north, Sian (Singan), capital of the highland province of Shensi, concentrates the fur trade of a large mountain wilderness to the west. Several blocks on the main street form a great fur market for the sale of mink and other skins used to line the official robes of mandarins.[1203]

[Sidenote: Mountain carriers.]

Like seas, deserts, and other geographical transit regions, mountains too under primitive conditions develop their professional carriers.

These collect in the piedmont, where highway and mule train cease, and where the steep track admits only human beasts of burden, trained by their environment to be climbers and packers. These mountain carriers are found on the Pacific face of the coast ranges of North and South America from the peninsula of Alaska to the Straits of Magellan. They are able to pack from 100 to 160 pounds up a steep grade. The Chilkoot Indians, men, women and children, did invaluable service on the White Horse and Chilkoot pa.s.ses during the early days of the Klondike rush.

They had devised a well-arranged harness, which enabled them better to carry their loads. Farther south in British Columbia the piedmont tribes had once a like importance; there they operated especially from the town of Hope on the lower Frazer River as a distributing center. The Mexican carrier is so efficient and so cheap that he enters into serious compet.i.tion with modern schemes to improve transportation, especially as the rugged relief of this country makes those schemes expensive.[1204] The Indians of the eastern slope of the Andes pack India rubber, in loads of 150 pounds each, from the upper Purus and Madeira rivers up to the Andean plateau at a height of 15,000 feet, and there transfer their burdens to mules for transport down to the Peruvian port of Mollendo.[1205]

The r.e.t.a.r.ded mountain peoples on the borders of the Central Asia plateau employ the same primitive means of transportation. The roads leading from the Sze Chuan province of western China over the mountain ranges to Tibet are traversed by long lines of porters, men, women and children, laden with bales of brick tea,[1206] the strongest of them shouldering 350 pounds. The Bhutia coolies of Sikkim act as carriers on military and commercial expeditions on the track across the Himalayas between Darjeeling and s.h.i.+gatze. Colonel Younghusband found that these Bhutias, who were paid by the job, would carry a pack of 250 to 300 pounds, or three times the usual burden of a Central Asia carrier. Landon cites the case of a Bhutia lady who was said to have carried a piano on her head from the plains up to Darjeeling (7150 feet).[1207] In Nepal, women and girls, less often men, have long been accustomed to carry travellers and merchandise over the Himalayan ranges.[1208] In the marginal valleys of the Himalayas, like Kashmir and Baltistan, the natives are regularly impressed for _begar_ or carrier service on the English military roads to strategic points on the high mountain frontier of the Indian Empire.[1209] So the Igorots of the Luzon province of Benguet pack all goods and supplies from Naguilian in the lowlands up 4000 feet in a distance of 25 miles to their little capital of Baguio; for this service they are now paid one peso (46 cents in 1901) a day with food, or ten times as much as under the Spanish rule.[1210]

[Sidenote: Power of mountain barriers to block or deflect.]

If the historical movement slackens its pace at the piedmont slope, higher up the mountain it comes to a halt. Only when human invention has greatly improved communication across the barrier are its obstacles in part overcome. The great highland wall stretching across southern Europe from the Bay of Biscay to the Black Sea long cut off the solid ma.s.s of the continent from the culture of the Mediterranean lands. Owing to these mountains Central Europe came late into the foreground of history, not till the Middle Ages. Even the penetrating civilization of Greece reached it only by long detours around the ends of the mountain barrier; by Ma.s.silia and the Rhone, by Istria and the Danube, Greek commerce trickled through to the interior of the continent.

Where mountains fail to check, they deflect the historical movement. The wall of the Carpathians, bulwark of Central Europe, split the westward moving Slav hordes in the 6th century, diverting one southward up the Danube Valley to the Eastern Alps, and turning one northward along the German lowlands.[1211] The northward expansion of the Romans, rebuffed by the high double wall of the Central Alps, was bent to the westward over the Maritime, Cottine and Savoy Alps, where the barrier offered the shortest and easiest transmontane routes. Hence Germany received the elements of Mediterranean culture indirectly through Gaul, second-hand and late. The ancient Helvetians, moving southward from northern Switzerland into Gaul, took a route skirting the western base of the Alps by the gap at Geneva, and thus threatened Roman Provincia. Caesar's campaigns into northern Gaul were given direction by the ma.s.sive Central Plateau of France.[1212] The rugged and infertile area of the Catskills long r.e.t.a.r.ded the westward movement in colonial New York and deflected it northward through the Mohawk depression, which therefore had its long thin line of settlements when the neighboring Catskills were still a "bare spot."

[Sidenote: Significance of mountain valleys.]

In their valleys, mountains lose something of their barrier nature, and approximate the level of the plains. Here they harbor oases of denser population and easier intercourse. Valleys favor human settlement through the milder climate of their lower elevation, the acc.u.mulation of soil on their floors, their sheltered environment, and their command of such routes of communication as the highlands afford. They are the avenues into and within a mountain system, and therefore radically influence its history by their direction and location. The Central Plateau of France, through the valleys of the Alliers and upper Loire, is most accessible from the north; therefore in that direction it has maintained its most important historical connections,[1213] from the days of Caesar and Vercingetorix. The ma.s.sive highland region of Transylvania, which opens long accessible valleys westward toward the plains of the Theiss and Danube, has since the eleventh century received thence Hungarian immigration and political dominion.[1214] Its dominant Roumanian population, however, seems to have fled thither from the Tartar-swept plains to the southeast.

The anthropo-geography of mountain valleys depends upon the structure of the highlands themselves, whether they are fold mountains, whose ranges wall in longitudinal valleys, or dissected plateaus, whose valleys are mostly transverse river channels leading from the hydrographic center out to the rim of the highlands. Longitudinal valleys are not only long, but also broad as a rule and often show a nearly level floor.[1215] They therefore form districts of considerable size, fertility, and individuality, and play distinct historical roles in the history of their respective highlands. Such are the upper Rhone Valley with its long line of flouris.h.i.+ng towns and villages, the Hither Rhine, the Inn of the Tyrol and the Engadine, the fertile trough of the meandering Isere above Gren.o.ble,[1216] the broad Orontes-Leontes valley between the Lebanon and Anti-Lebanon where Kadesh and Baalbec were once the glory of northern Syria. Such is the central trough of the Appalachian Mountains, known as the Great Appalachian Valley, seventy-five miles wide, subdivided into const.i.tuent valleys of similar character by parallel, even-crested ridges following the trend of the mountains. These are drained by broad, leisurely rivers, bordered by fertile farms and substantial towns. Transverse valleys, on the other hand, are generally narrow, with steep slopes rising almost from the river's edge and supporting only small villages and farms. A comparison of the s.p.a.cious, smooth-floored valley of Andermatt with the wild Reuss gorge, of the fertile and populous Shenandoah Valley in the Southern Appalachians with the canon of the Kanawha in the c.u.mberland Plateau, makes the contrast striking enough.

[Sidenote: Longitudinal valleys.]

Longitudinal valleys, by reason of their length and their branching lateral valleys, are the natural avenues of communication within the mountains themselves. They therefore give a dominant direction to such phases of the historical movement as succeed in pa.s.sing the outer barrier. The series of parallel ranges which strike off from the eastern end of the Tibetan plateau southward into Farther India have directed along their valleys the main streams of Mongolian migration and expansion, heading them toward the river basins of Burma and Indo China, and away from India itself.[1217] While Tibetan elements have during the ages slowly welled over the high Himalayan brim and trickled down toward the Gangetic plain, Burma has been deluged by floods of Mongolians pouring down the runnels of the land. A carriage road follows the axis of the Central Alps from Lake Geneva to Lake Constance by means of the upper Rhone, Andermatt, and upper Rhine valleys, linked by the Furca and Oberalp pa.s.ses. The Roman and Medieval routes northward across the Central Alps struck the upper Rhine Valley above Coire, (the ancient Curia Rhaetorum); this natural groove gave them a northeastward direction, and made them emerge from the mountains directly south of Ulm, which thereby gained great importance. The trade routes from Damascus and Palmyra which once entered the Orontes-Leontes trough in the Lebanon system found their Mediterranean termini south near Tyre or north near Antioch, and thus contributed to the greatness of those ancient emporiums. The Great Appalachian Valley used to be a highway for the Iroquois Indians, when they took the warpath against the Cherokee tribes of Tennessee. Later it gave a distinct southwestward trend to pioneer movements of population within the mountains, blending in its common channel the Quakers, Germans and Scotch-Irish from Pennsylvania, with the English and Huguenot French of the more southern colonies. In the Civil War its fertile fields were swept by marching armies, all the way from Chattanooga to Gettysburg.

[Sidenote: Pa.s.ses in mountain barriers.]

The barrier nature of mountains depends upon their height and structure, whether they are ma.s.sive, unbroken walls like the Scandinavian Alps and the Great Smoky range; or, like the Welsh Highlands and the Blue Ridge, are studded with low pa.s.ses. The Pyrenees, Caucasus and Andes, owing to the scarcity and great height of their pa.s.ses, have always been serious barriers. The Pyrenees divide Spain from France more sharply than the Alps divide Italy from France; owing to their rampart character, they form the best and most definite natural boundary in Europe.[1218] Epirus and Aetolia, fenced in by the solid Pindus range, took little part in the common life of ancient Greece; but the intermittent chains of Thessaly offered a pa.s.sway between Macedon and h.e.l.las. The Alps have an astonis.h.i.+ng number of excellent pa.s.ses, evenly distributed for the most part. These, in conjunction with the great longitudinal valleys of the system, offer transit routes from side to side in any direction. The Appalachian system is some three hundred miles broad and thirteen hundred miles long, but it has many easy gaps among its parallel ranges, so that it offered natural though circuitous highways to the early winners of the West. The long line (400 miles) of the Hindu Kush range, high as it is, forms no strong natural boundary to India, because it is riddled with pa.s.ses at alt.i.tudes from 12,500 to 19,000 feet.[1219] The easternmost group of these pa.s.ses lead down to Kashmir, and therefore lend this state peculiar importance as guardian of these northern entrances to India.[1220] The Suleiman Mountains along the Indo-Afghan frontier are an imperfect defence for the same reason. They are indented by 289 pa.s.ses capable of being traversed by camels. The mountain border of Baluchistan contains 75 more, the most important of which focus their roads upon Kandahar. Hence the importance to British India of Kandahar and Afghanistan. Across this broken northwest barrier have come almost all the floods of invasion and immigration that have contributed their varied elements to the mixed population of India. Tradition, epic and history tell of Asiatic highlanders ever sweeping down into the warm valley of the Indus through these pa.s.ses; Scythians, Aryans, Greeks, a.s.syrians, Medes, Persians, Turks, Tartars, and Mongols have all traveled these rocky roads, to rest in the enervating valleys of the peninsula.[1221]

[Sidenote: Breadth of mountain barriers.]

Mountains folded into a succession of parallel ranges are greater obstructions than a single range like the Erz, Black Forest, and Vosges, or a narrow, compact system like the Western Alps, which can be crossed by a single pa.s.s. Owing to this simple structure the Western Alps were traversed by four established routes in the days of the Roman Empire. These were: I. The _Via Aurelia_ between the Maritime Alps and the sea, where now runs the Cornice Road. II. The _Mons Matrona_ (Mont Genevre Pa.s.s, 6080 feet or 1854 meters [Transcriber's Note: printer's error incorrectly printed as kilometers.]) between the headstream of the Dora Riparia and that of the Durance, which was the best highway for armies. III. The Little St. Bernard (7075 feet or 2157 meters), from Aosta on the Dora Baltea over to the Isere and down to Lugdunum (Lyons). IV. The Great St.

Bernard (8109 feet or 2472 meters) route, which led northward from Aosta over the Pennine Alps to Octodurus at the elbow of the upper Rhone, where Martigny now stands. Across the broad double rampart of the Central Alps the Roman used chiefly the Brenner route, which by a low saddle unites the deep reentrant valleys of the Adige and Inn rivers, and thus surmounts the barrier by a single pa.s.s. However, a short cut northward over the Chalk Alps by the Fern Pa.s.s made closer connection with Augusta Vindelicorum (Augsburg). The Romans seem to have been ignorant of the St. Gotthard, which, though high, is the summit of an unbroken ascent from Lake Maggiore up the valley of the Ticino on one side, and from Lake Lucerne up the Reuss on the other.

Mountains which spread out on a broad base in a series of parallel chains, and through which no long transverse valleys offer ready transit, form serious barriers to every phase of intercourse. The lofty boundary wall of the Pyrenees, a folded mountain system of sharp ranges and difficult pa.s.ses, has successfully separated Spain from continental Europe; it has given the Iberian Peninsula, in the course of a long history, closer relations with Morocco than with its land neighbor France. It thus justifies the French saying that "Africa begins at the Pyrenees." The Andalusian fold mountains stretching across southern Spain in a double wall from Trafalgar to Cape Nao, accessible only by narrow and easily defended pa.s.ses, enabled the Moors of Granada to hold their own for centuries against the Spaniard Christians. The high thin ridges of the folded Jura system, poor in soil and spa.r.s.ely populated, broken by occasional "cluses" or narrow water-gaps admitting the rivers from one elevated longitudinal valley to another, have always been a serious hindrance to traffic.[1222]

[Sidenote: Circuitous routes through folded mountains.]

Such mountains can be crossed only by circuitous routes from pa.s.s to pa.s.s, ascending and descending each range of the system. The Central Alps, grooved by the longitudinal valleys of the upper Rhone, Rhine and Inn, make transit travel a series of ups and downs. The northern range must be crossed by some minor pa.s.s like the Gemmi, (7553 feet) or Panixer (7907 feet) to the longitudinal valleys, and the southern range again by the Simplon (6595 feet), San Bernadino (6768 feet), Splugen (6946 feet) or Septimer (7582 feet) to the Po basin. Across the corrugated highland of the Hindu Kush, lying between the plains of the Indus and the Oxus, the caravans of western Asia seek the market of the Punjab by a circuitous route through the Hajikhak Pa.s.s (12,188 feet) or famous Gates of Bamian over the main range of the Hindu Kush, by the Unai Pa.s.s over the Paghman Mountains to Kabul at 5740 feet, and then by gorges of the Kabul River and the Khaibar Pa.s.s (6825 feet) down to Peshawar. This road presents so many difficulties that caravans from Turkestan to India prefer another route from Merv up the valley of the Heri-Rud through the western hills of the Hindu Kush to Herat, thence diagonally southeast across Afghanistan to Kandahar, and thence by the Bolan Pa.s.s down to the Sind. The broad, low series of forested mountains consisting of the Vindhyan and Kaimur Hills, reinforced by the Satpura, Kalabet, Gawilgarh ranges, Mahadeo Hills, Maikal Range and Chutia Nagpur Plateau as a secondary ridge to the south, forms a double barrier across the base of peninsular India. It divides the Deccan from Hindustan so effectually that it has sufficed to set limits to any Aryan advance en ma.s.se southward. It kept southern India isolated, and admitted only later Aryan influences which filtered through the barrier.

To people accustomed to treeless plains, these wide belts of wooded hills were barrier enough. Even a few years ago their pa.s.ses were dreaded by cartmen; most of the carriage of the country was effected by pack-bullocks. Even when roads were cleared through the forests, they were likely to be rendered impa.s.sable by torrential rains.[1223]

[Sidenote: Dominant trans-montane routes.]