PLAIN All those parts of the dry land which cannot properly bo called mountainous are plains, and such compose by far the greater part of the earth's surface. Thus, for instance, it has been estimated that in South America the plains are to the mountainous country as 4 to 1. We are not aware that a similar calculation has been made for the other parts of the world, nor are there perhaps materials sufficiently exact for the purpose.
The word plain has but an indefinite meaning of itself, and seems to be rightly understood only when used in opposition to the word mountains, or when conjoined to the name of some known place, in which case it means the country itself so designated, or the environs of some particular spot. Thus we speak of the cities of the plains, the valleys of the plains, the plains of Lombardy, the plains of Quito, &c.
It were a great error to imagine that by the word plain a perfectly horizontal surface is always understood. In its usual acceptation it means a greater or less extent of country, flat in its general level as compared with a mountainous country. The more perfectly even and horizontal the surface, the better does it deserve to be called a plain, such as the plains of Venezuela and of the lower Orinoco, Mesopotamia, &c. But the surface of the ground may be gently waving, as Salisbury plain, and the Ukraine ; or more prominently undulated, as the plain round Paris; or it may be studded with hills, as the plains of the Cassiquiare; or it may be traversed by valleys more or less wide and deep, like that part of France which lies between the Loire and the Garonne; or intersected with deep ravines, as the central plains of Russia, without ceasing on such accounts to be a plain.
Plains have been divided into two classes, high and low; but a moment's reflection will show that such denominations can apply rigorously only to the two extremities of a scale of elevation, at the bottom of which would stand, for example, the delta of Egypt or the llanos of South America (which latter are raised only about 150 feet above the level of the ocean, and in some places even less), and at the top the plain of Antisana, 13,435 feet above the sea-level; whereas the greater number of plains are found at intermediate heights, as the following will show: —
Feet nlwvq the Ocean Mysore .... 2300 to 2G00 Table-land of Persia . . 3800 to 4200 &c.
Though we generally regard those plains which are the least raised above the surface of the ocean as the lowest, it must not be forgotten that round the Caspian and Aral there are plains of many thousand square miles considerably depressed below the sea-level; as is also the case with the plain or valley of the Jordan. The term ptateau has often been given exclusively to elevated plains, but this also is incorrect, inasmuch as by a plateau is sometimes meant a great extent of country considerably raised above the rest of the land, and having its mountains, its plains, and its valleys, as is particularly exemplified in the minor plateau of Albania, and in the great plateau of Central Asia. The latter contains four great chains of mountains, the Altai' on the north, the Thian-Chan and the Huen-lun in the interior, and the Himalaya on the south, between which are the vast plains of Dzoungaria, of Tongout, and of Tibet, with their rivers, valleys, and lakes.
Table-land, properly so called, is an elevated plain rising abruptly from the general level of the country, and being, as it were, the broad and horizontal or gently undulating top of an immense mountain, as the Nilgherry district of India. Sometimes there arc several such, set one upon the other, at least on one or two sides, when they are called platforms or terraces, as those on the eastern slope of the Cordillera of New Mexico.
Some writers regard the words plateau and table-land as merely the French and English names for the same sort of elevation. Humboldt is of opinion that these names should be confined to elevations producing a sensible diminution of temperature, and accordingly to such heights only as attain to 1800 or 2400 feet. Some again, as Balbi, give the name of plateau to all high and extensive mountaintracts.
Generally speaking, the plains of Europe are of middling elevation, the extremes of high and low being principally found in Asia and America. Thus while the great plains of Central Asia, about Ladak, Tibet, and Katchi, and round Koukounoor and elsewhere, attain a height similar to those of Quito and Titicaoa, or from 9000 to 12,000 feet, the great marshy plains of Siberia along the borders of the Frozen Ocean are very slightly raised above the sea level, as is also the case with the plains of Bengal at the mouths of the Ganges, the whole of Mesopotamia, the Tehama of Arabia, &c.
In South America, contrasting with the lofty plains of Quito, of Santa Fe de Bogota, &c, are the llanos and the plains of the Amazon; while in North America, the interminable prairies and the low swamps round New Orleans form a striking contrast with the Rocky Mountains and the elevated plains of Mexico.
Of Africa little is known, but there is reason to believe that if the plains of Lower Egypt and part of the Sahara are very low, there may be high plains in the mountainous regions.
Plains differ not only in their elevation, but in the horizontally of their surface and general slope, and in the nature of their soil; which circumstances, together with their geographical position, influence their climate and productions, and give to the most considerable among them a particular character and physiognomy. It may be remarked that the rocky and sandy plains belong almost exclusively to the hot and temperate regions of the old world. The plains of America are generally characterised by their gramineous covering or their vast forests; the Asiatic steppes by a twofold appearance, being in some parts studded with low saline plants, and in others, as in Southern Russia, Siberia, and Turkistan, covered with plants of the families of the Corapositso and LeguminossB; while the greater part of the European plains are richly cultivated.
We say such are the general characteristics, for there are plains of similar character and physiognomy in very different and widely separated regions of the world. The high land of the Campos Parexis, for instance, in South America, is very similar in physiognomy to the desert of Gobi in Asia. The Desiertos, near Coquimbo, are of the same character as the Sahara. The Puszta of Hungary resemble the savannas of the New World; and the pampas of Cordova are not unlike some of the Siberian steppes.
Though, as we have said, plains constitute by far tho greater portion of the earth's surface, and are very varied n their appearance, there are nevertheless some which are remarkable not only fur their extent, but for the peculiarities which distinguish them; peculiarities derived, no doubt, in part from the circumstances attending their ortginal formation, and which no subsequent causes have been able to obliterate. These remarkable plains are known' under the names of deserts, landes and heaths, steppes savannas and prairies, llanos, pampas, and selvas (pr forest plains') of the Maraiion. Deserts having been already described under their particular head, we shall here give a brief account of the others. ,. u Wms ,il Heaths and Landes of Europe.—From Paris to Moscow and Cazan on the one hand, and to Astrakan on the other, is one continued plain, comprising tho lowlands of Northern France, the Netherlands, the North of Germany, the whole of Prussia, and .the greater part of Poland and Russia, as far as the first terraces of the Ural. Besides which there are many minor plains, as those of Wallachi^ and Bulgaria, Hungary, Lombardy, &c The antient civilization of Europe has covered the greater part of its plains with cultivation and rendered some of these lands the richest in the world (the plains of Lombardy); nevertheless there are some spots which seem to defy all human efforts to bring them into cultivation; such are those between the Lower Volga and the Ural, of which we shall speak more fully in describing the steppes, and such are the heaths and landes. Of these, next to those of Russia, the most extensive are in Lapland and West Gothland. But the chief landes and heaths, properly so called, lie in the northwest of Germany. In Lower Silesia, Lusatia, and Brandenburg, there is little else than sand, and also in Poraerania and Mecklenburg, studded with a few hills, numerous lakes, and, along the maritime parts of the latter, having some woods of oak. In Hanover the gentle acclivities are covered with heath, which extends through part of Holstein to the centre of Jutland. The most sterile parts of Hanover however are the landes of Liineburg and Verden between the Elbe and the Weser, and those of Meppen on the right bank of the Ems. Those of Liineburg and its vicinity are said to cover a space of about 6000 square miles. These landes are covered with heath, with pine woods, and marshes. On the west of the Ems, about Bentheim, there are also extensive landes covered with swamps and stagnant pools. In the province of the Lower Rhine, in me environs of Monjoie, between Eupen and Malmedy, we again find vast landes coated with heath. In France, of which country about one-twelfth is unproductive soil, there are extensive landes and barren spots. That tract which extends eastward from the right bank of the Adour, and gives its name to the department, consists almost wholly of pools, marshes, and heath, and this sterile plain extends a great way into the department of the Gironde. The shingle plain of Crau, in the department of the Bouches du Rhone [bouches Dtj Rhone], is well known, and likewise the sterile chalky plain of La Champagne Pouilleuse. In the kingdom of Naples there are considerable landes.
Steppes.—This name, which is Russian, is given more particularly to the extensive plains which lie on the northwest of Asia. Considered as a whole, the steppes have a character quite different from the other great plains of the world, though in different parts they present partially the distinguishing features which characterise the llanos, the savannas, the pampas, the sandy deserts, &o. Generally speaking, they consist of rich pastures intermingled with woods, barren sands, muriatifcrous clay, and abounding in lakes, pools, and streams of salt and bitter waters.
From the sea of Azof on the west to the foot of the Little Altai on the east, there is a band extending, in a north-east direction, from the mouth of the Kuban towards Tomsk, where the undulations of the plain prevent the egress of the waters, which, percolating through a highly saline soil, are collected hi the hollows into innumerable lakes and pools of salt water, which give a peculiar feature and interest to these steppes.
Further northward, the Siberian plains have a general slope towards the Frozen Ocean, and are intersected by the great rivers Obi, Yenisei, and Lena; between the lower courses of which extend immense frozen marshes, covered with, moss, and interspersed with a few sandy and clayey hills crowned with tufts or clumps of stunted birch anil other dwarf shrubs.
The greater part of what are properly called the steppes form a considerable part of the country known as Independent Tartary, which is inhabited by the nomadic hordes of the Kirghis Cossacks.
The steppe which lies on the north-west of the Caspian, bounded by the Caucasus, the sea of Azof, the lower course of the Don, and thence to the Ural or Iai'k, is inhabited by the Cossacks of the Black Sea and the Nogay Tartars. The whole of this steppe is characterised as composed of hills of a moving shelly sand, between which are beautiful green pastures, and marshy hollows with reeds and clumps of trees, among which, are willows, poplars, and wild olive. There urajirimerous salt streams and brine pools, barren patches covered with a saline efflorescence, and in many places tufts of saline plants. The fertility of the hollows seems due to a sheet of water which, coming from the hilly range called Obstchei Sirt, a branch of the Ural, flows immediately below the sandy surface, being probably relained by an impervious substratum.
Between the Iai'k on the west and a low ridge of hills on the, east, which may be regarded as a south-eastern continuation of the Ural, and which extends between the Aral and> the Caspian, is another steppe similar in character to that already described. It is occupied by the Kirghis of the little horde; while what is called the central or middle horde ranges over the vast steppe contained between the lake Aral and the Sir on the south, the low hills already mentioned .on the west, the Ouloustaou and Naourgiuskaia ranges on the north, and the Sarasou on the east. With the exception of the Sir, all the waters of this great basin lose themselves in the sand, or in lakes more or less salt, the principal of which is the famous Aksakal Bari.
To the north of the last-mentioned steppe lies the great steppe or plain of Ischim, which extends from the eastern slope of the southern extremity of the TJral, across the Tobol, to the Irtish. It takes its name from the river Ischim, which, dividing it nearly in two, falls into the Irtish near Petropavloffskoi. The north-east part of this steppo towards Tara, on the left bank of the Irtish, is covered with dense forests abounding in game and rich in furs. Sables are in great number, but of indifferent quality; besides which there are bears, wolves, foxes, ermines and squirrels, beavers, lynxes, gluttons, and others, and still further north are reindeer. The Kirghis of the middle horde sometimes encamp in the plains of Ischim, of similar general character to those already described. Crossing the Irtish, we enter the great steppe of Baraba, occupying all the space between that river and the Upper Obi. This steppe, lying nearer the foot of the mountainous district of the south and east, contains numerous lakes and pools, particularly in its southern portion. This district is in many places extremely fertile, and along the watercourses the grass grows luxuriantly. The north and northwest parts are wooded, but the more southern, those lying along the Irtish and towards the Altai', have few trees, and are less fertile. The lake Tschany, the largest and nearly the most northerly of the great group of lakes, abounds in fish; the surrounding country is extremely fertile, and abounds in aquatic game, the chief nourishment of the Tartar tribes who live dispersed along the frontiers of this canton. Interspersed with the sandy, barren, and saline spots, are many places where there is excellent land for tillage, in which grain and flax succeed well. In those parts of this district which suit them there are great quantities of elks, roebucks, and wild boars. The Kirghis of the great horde occupy a more mountainous country to the south of the Sarasou.
Besides these great steppes, there are numerous other patches of greater or less extent and similar general character in Central Siberia, reaching from the Ural to the Lena.
Previous to the nominal subjection of the wandering hordes to Russia, that country had lines of fortified posts for its protection against these predatory bands; but now that the different hordes of Kirghis acknowledge the supremacy of Russia, and their several chiefs are paid by the Russian government, many of these posts have been abandoned, and open villages are now multiplying along the roads by which the Russian caravans travel towards Kiachta and in the direction of the mining districts of the Altai'. The inhabitants of these villages, some of which are very large, are the only stationary population of the steppes. The wandering tribes are very numerous, and are continually shifting their ground to find food for their numerous cattle, consisting of horses, camels, horned cattle, sheep, and goats. These herds, together with the hooty taken in their incursions upon the Calmucks and others, form the sole wealth of the Kirghis, who lead easy and independent lives.
The extent of the steppes "properly so called, excluding the marshy plains of the north, may he about 1,000,000 square miles.
Savannas or Prairies.—The central part of North America, from the Frozen Ocean to the Gulf of Mexico, may be regarded as one continuous plain, divided by a low watershed into the north-eastern basin, whose waters flow into the Polar Sea, Hudson's Bay, and, by the great lakes and St. Lawrence, into the Atlantic, and the basin of the' Missouri and Mississippi, whose waters fall into the Gulf of Mexico.
This immense tract of country, estimated by Humboldt at 2,430,000 square miles, is extremely varied in climate, in character, and productions; for while the northern portion, which is watered by the Mackenzie, Back's River, the Churchill, and the Saskatchewan, is condemned for the greater part of the year to all the horrors of an iron-bound soil and stunted polar vegetation, palms and other tropical trees grow at the extremity of the southern portion. It is this southern basin, watered by the mighty Missouri and Mississippi, with their abundant affluents, that contains those extensive grass-covered tracts, the savannas and prairies. They lie cniefly on the western side of the Mississippi, though along the Illinois river they are found to the extent of 1,200,000 acres, and also in other parts of the basin east of the Mississippi. But the whole of the territory from the right bank of the Mississippi to the mountains is not one continued savanna, or even an unbroken horizontal plain; for it is rises towards the mountains, many of whose spurs are reached by the Missouri, which has erroded their extremities into bluffs. These ridges form the boundaries of the basins of the great tributary streams, the Platte, the Kanses, the Osage, the Arkansas, &c. Woods are also occasionally met witli along the Mississippi and other watercourses, as likewise in Arkansas; and in some places, as between the Platte and the Missouri, there are extensive surfaces of moving sands resembling those of the African desert. Elsewhere again, as from the mouth of the Arkansas along the Mississippi, a distance of 450 miles long and 40 miles broad, the soil is all swamps and pools, with abundance of trees: this is also the case above Illinois lake and elsewhere. Along the upper Missouri, from the territory of the Mandans, is an interminable plain without trees or shrubs except in the marshy spots. In various parts, but more especially along the borders of the great plain, and in Arkansas, salt is found.
The savannas, or prairies, as they are also called, are divided by Flint, an American writer, into three kinds:—1, the heathy or bushy, which have springs and are covered with small shrubs, grape-vines, &c, very common in Indiana, Illinois, and Missouri; 2, dry or rolling, generally destitute of water and almost of all vegetation but grass; they are the most common and extensive: the traveller may wander for days in these vast and nearly level plains without wood or water, and see no object rising above the horizon; 3, the alluvial or wet prairies, the smallest division; they are covered with a rich vegetation of tall rank grass. The soil is deep, black, friable, and fertile, and abounding in pools without issue, left by the floodiugs of the rainy season. It is over the second kind chiefly that the bisons wander in herds of from 40,000 to 50,000. Stags, or more properly wapitis, are also very numerous; and between the Arkansas and Red rivers there are droves of wild horses. Deer are also numerous; and along the borders of the Missouri, above the Platte, or shallow river, the antelope abounds in herds of several hundreds. In summer wild goats are seen in vast numbers along the Mississippi. Above the Mandan villages are grizzly bears; and badgers, beavers, otters,foxes, wolves, racoons, opossums, squirrels, porcupines, and skunks inhabit the same region. To this enumeration of Warden's and Flint's, Lyell adds the jaguar. The waters teem with alligators and tortoises, and their surface is covered with millions of migratory water-fowl, which perform their annual voyage between the Canadian lakes and the shores of the Mexican Gulf.
Llanos.—The whole interior of South America, from the mountains of Caracas on the north to the Straits of Magalhaens on the south, is divided by comparatively low transverse ridges, running east and west iutQ three great P. C, No. 1129.
basins; that of the Orinoco on the north, that of the Amazon or Maranon in the centre, and that of the La Plata on the south. The first comprises the llanos, vast plains occupying a surface of 260,000 square miles. They may be divided into two principal portions: the first, beginning at the mouths of the Orinoco, extends westward as far as the Andes of New Granada, being bounded on the north by the Caracas, and on the south by the mountainous group of Parime and the Rio Apure, an affluent of the lower Orinoco. The other portion of the llanos, which is twice as extensive as the first, reaches from the Apure on the north to the Caqueta (an affluent of the Maranon) on the south; having the Andes on the west, and the sierra of Parime and the Orinoco on the east. The inclination of these plains is to the east and south, and they are traversed by many streams, which, taking their rise from the eastern slope of the Andes, bear their tributary waters to the Orinoco. As the medium height of the llanos does not exceed 200 feet, the course of the rivers is very slow and often scarcely perceptible. The chief characteristic of the llanos, says Humboldt, is the absolute want of hills and inequalities, the perfect level of every part of the soil. Often in the space of 270 square miles there is not an eminence of a foot high. This resemblance to the surface of the sea strikes the imagination most powerfully where the plains are altogether destitute of palmtrees, and where the mountains of the shore and of the Orinoco are so distant that they cannot be seen. This unvarying equality of surface reigns without interruption from the mouths of the Orinoco to the Villa de Aurore and Ospinos, under a parallel of 540 miles in length, and from San Carlos to the Caqueta, on a meridian of 600 miles.
There are however, notwithstanding this uniformity of surface, two kinds of inequalities in the llanos. The first, called broncos, are horizontal banks of sandstone or limestone standing four or five feet higher than the rest of the plain, and sometimes many leagues in length. The second kind of inequality, called mesa, consists of convex eminences rising to the height of a few fathoms.
The llanos have different names in different parts: thus, from the Mouth of the Dragon, the llanos of Cumano, of Barcelona, and of Caracas or Venezuela, follow from east to west, when, turning southward from 8° N. lat., between the meridians of 67° 40' and 70° 40', we find the llanos of Varinas, Casuare, the Meta, Guaviarc, Caguan, and Caqueta. All these are again subdivided.
The aspect of the llanos is somewhat dissimilar in different places; but the greatest difference depends upon the seasons. The local dissimilarity arises chiefly from the nature of the palm-trees scattered about, which vary in different places, and also from the greater or less abundance and variety of the dicotyledonous plants which are intermixed with the grasses, the height of which latter is also very unequal, being sometimes only a few inches at a distance from the watercourses, and rising to a height of four feet in their vicinity. In this high grass the jaguar, or American tiger, lurks to spring upon the mules and horses that cross the plain. But the season of drought or of rain entirely changes the aspect of the greater part of the llanos. In the rainy season, says Humboldt, the llanos display a beautiful verdure, but in the time of great drought they assume the aspect of a desert. The grass is then reduced to powder, the earth cracks, the alligators and great serpents remain buried in the dried mud, till awakened from their long lethargy by the first showers of spring. These phenomena are observed on barren tracts of fifty or sixty leagues in length where the llanos are not traversed by rivers.
The principal and almost the only trees of the llanos are different varieties of palms. The Corypha tectorum, or Palma de Cobija, solitary or in clumps, rises here and there as a landmark through these trackless plains. It is chiefly found in the llanos of Caracas from Mesa de Peja, as far as Guayaval. Farther north and north-west, near Guavare and San Carlos, its place is taken by another species of the same genus. Other palm-trees appear to the south of Guayaval, especially the Piritu, with pinnate leaves, and the Murichi, whose beautiful verdure, at the period of the greatest drought, contrasts with the mournful aspect of the grey and dusty leaves of the cobija. Two or three other species of trees besides palms are also found in the llanos, and it is round these clumps that the llanos are the most fertile.
The great wealth of the llanos consists in the numerous herds which they feed. The first horned cattle were let loose in these extensive pastures by Christoval Rodriguez, about the year 1548, since which lime they have increased to almost countless numbers. About 98,000 head of cattle are said to wander in the pastures round Calaboza. But, according to M. Depons, there are, from the mouths of the Orinoco to the lake of Maracaybo, 1,200,000 oxen, 180,000 horses, and 90,000 mules, the annual produce of which herds is estimated at about 5,000,000 francs. The richest proprietors are said to mark as many as 14,000 head every year, and sell to the number of five or six thousand. According to official documents, prior to the Revolution the exportation of hides from the whole capitania-general amounted annually, from the West India Islands alone, to 174,000 skins of oxen and 11,000 of goats; and as in this account no mention is made of fraudulent dealings iu hides, it would appear that the number of 1,200,000, stated above, is muali underrated.
All the parts of the llanos are not equally favourable for the breeding of mules and oxen; but in some of those plaoes, where the herds are less numerous, the pastures are so fertile as to furnish meat of an excellent quality for provisioning the coast.
The horses of the llanos are not very large, but are descended from a fine Spanish breed. Deer are natives of these plains.
The greatest curiosity of the llanos are the gymnoti, or electrical eels, which live in the pools as well as in the rivers of this part of South America. We may also mention, as distinguishing the llanos from the pampas, and from the plains of North America, the Sahara, and the steppes of Asia, the total absence of any formation of muriate of soda.
Pampas, from an Indian word, which, in the Quichua language, signifies properly a flat, is the name given to extensive plains in the southern and central parts of South America. Those which lie to the south and north-west of Buenos A vies are called, the former the Pampas of Buenos Ayres, or simply the Pampas, and the latter the Pampas of Cordova. The plains to the south of the province of Chiqtfitos bear the name of the Pampas de Huanacos. There is also one more to the north, between the river Beni and the river Marmore, a tributary of the Madeira; and lastly, to the north between Huallaga and the Ucayal there is another, called the Pampas del Sacramento.
The Pampas of Buenos Ayres are bordered on the West by the forests which lie along the base of the Andes of Chile; on the east by the Atlantic; on the south by the Rio Negro and Patagonia, the interior of which, though little known, seems to be of the same nature with the pampa itself; and on the north-east by the Rio de la Plata. In the direction due north the pampa narrows between the Parana and a ridge coming from the Andes, called the Sierra de Cordova. This region, reckoning to the foot of the mountains on the west, occupies a surface of about 315,000 square miles. This plain has no general slope, or rather it slopes so gently townrds the east, that the slightest inequalities, together with the absorbing nature of the soil and the great evaporation, are sufficient to arrest the course of the waters; so that, with the exception of the rivers Colorado and Negro, which come from the Cordilleras, and which traverse the southern part of the pampas, and the Salado, a small stream which Hows into the Rio de la Plata at its mouth, the pampas have no running waters, but, instead of them, a great many shallow pools, of which the water is often brackish. There is one at about four hundred and fifty miles from Buenos Ayres, in the direction west-south-west, always filled with salt, from which the city of Buenos Ayres was yearly supplied before the port was thrown open to foreigners. The southern part of the pampas is sandy, with patches of saline plants and stunted trees; the northern parts are covered with grass, supplying fuod to large herds of cattle and wild horses, the descendants of those first introduced by the Spaniards. It is said that several million head of cattle and about half as many horses feed on the Pampas of Buenos Ayres. There are also wild beasts.
This plain is traversed by a road which leads from Buenos Ayres to Chile, along which tho traveller meets with huts, which form stations, distant from each other about seven or eight leagues, The journey may be made ou horseback or in a carriage, but it is sometimes dangerous, on account of the Indians.
The Pampa of Cordova extends from the right bank of the lower Parana to the Sierra de Cordova at the west. On the north it joins the sandy plains or travesia of Santiago del Estero.
This pampa resembles that already described in all things, excepting being traversed by a greater number of streams All these streams however, with the exception of the Rio Salado, which falls into the Parana, lose themselves in the sands, or end in marshes and lakes without issue, and which in the country are called Lagunas. Such is particularly the case with the Rio Dulce, which, rising in a fertile valley on the eastern slope of one of the lateral chains of the Andes, passes by S. Miguel de Tucumau and Santiago, and finally empties itself into the Lagunas de las Porongos; the same is also the case with the Rio Primero, on which is situated Cordova, the best of all the towns of Tucuman, the residence of a bishop, and where the Jesuits had formerly a celebrated university. Throughout the whole of the country between the Parana and the mountains to the west, from Cbaco on the north to the extreme southern extremity of the Pampa of Buenos Ayres, says Azara, there is neither river, lake, nor well that is not brackish. Even the Pilcomayo and the Vermcjo partake of this saltness; and the same author assures us that he has seen in lagunas, dried up by the heat, a layer of Epsom salts above three inches in thickness.
The inhabitants of the fertile valleys lying to the west and north of the plains of Tucuman, similar in some respects to Little Bucharia, rich in their Hocks, without ambition, and without care, close the day in rural amusements worthy of being sung by Theocritus and Virgil. It is nevertheless true that there are spaces of many square leagues in extent condemned to absolute sterility. The traveller may pass for days together over sands and stones, between which there spring up here and there some saline plants, without meeting with any other objects than a few isolated huts on the borders of some brackish stream; these barren districts are generally designated by the term travesia.
Pampa of Huanacos.—Leaving the Pampa of Cordova on the south, and travelling through forests swarming with bees, which extend beyond tho Rio Dulce and the Salado, we enter on the territory of the Ahipones, a race of very warlike Indians; after which, crossing the Rio Vermejo, we gain the plains of the Gran Chaco, occupied by more or less savage indigenous tribes. This region is traversed by the Rio Pilcomayo, which, passing near tho mines of Potosi, falls into the Paraguay below the city of Assumption. To the north lies the Pampa de Huanacos, adjoining the province of Chiquitos, bounded on the east by the great laguna of Xarayes, through which passes the frontier of Brazil; on the west by the heights of Santa Cruz de Sierra, and on the north by the forests of tho province of Moxos and the sandy plateau called Campos Parexis.
Pampa de Moxos is on the north of the province of Moxos, between the rivers Beni and Marmord; and between the junction of this latter and the Guapore, another source of the Madeira, are other pampas of considerable extent.
Pampa del Sacramento.—This pampa is situated on the north-west of Cuzco. It differs from the other pampas in having a more tropical vegetation, and in its soil not being saline. It occupies a surface of from 54,000 to 63,000 square miles.
Such are the principal pampas of South America; and, if we include a part of Patagonia as being of the same nature with the pampas, we shall have, without reckoning the pampas of Moxos and Sacramento, and a number of spots of similar character but less extent, an almost uninterrupted band, extending from the Campos Parexis, in latitude 15° S., to the bay of St. George in 45°, or about 2S00 geographical miles long and 300 wide, or a surface of 840,000 square miles of plain, partly sand, and partly marshy and saline, and producing hardly anything but pasture and a few stunted trees. Humboldt estimates the whole of the pampas of Rio de la Plata and Patagonia at 135,200 square leagues of 20 to the degree.
The Selvas, or forest-covered plain of the Maranon.—Independent of the vast forests which cover great part of the plains of North America, particularly on the east of the Mississippi, there is the immense plain of the Maranon in South America, extending over a surface of 2,340,000 square miles, of which about 719,000 are covered with primeval forests, the rest of the space being occupied by the waters, and by open patches of a character similar to the llanos and savannas, though little known. We merely mention tins region here as one of the most extensive continuous plains in the world.
If the great plains we have described owe their peculiar character to climate and situation, a very little reflection will suffice to show the immense influence which they in their turn must exercise over the climate of the regions contiguous to them, and the great modifications they must effect on mere astral temperature. Indeed the curves of the isothermal lines sufficiently prbve that the several climates of the earth depend on the joint action of solar irradiation, and the magnitude, distribution, conformation, soil, and productions of the solid parts of the globe, and the extent and relative position of the great bodies of water by which they are surrounded. Nor have the vast plains of Asia and America performed a less important part in the moral history of mankind, whether as having favoured or opposed the emigrations of nations and the progress of civilization.
Note - this article incorporates content from The Penny Cyclopaedia of the Society for the Diffusion of Useful Knowledge (1840)