[5] p. 2.—“The Llanos and Pampas of South America, and the Prairies of the Missouri.”
The physical and geognostical views entertained respecting the western part of North America have been rectified in many respects by the adventurous journey of Major Long, the excellent writings of his companion Edwin James, and more especially by the comprehensive observations of Captain Frémont. These, and all other recent accounts, now place in a clear light what, in my work on New Spain, I could only put forward as conjecture, on the subject of the mountain ridges and plains to the north. In the description of nature as well as in historical inquiries, facts long remain isolated, until by laborious investigation they are brought into connection with each other.
The east coast of the United States of North America runs from south-west to north-east, in the same direction as that followed in the southern hemisphere by the Brazilian coast from the river Plate to Olinda. In the two hemispheres two ranges of mountains exist at a short distance from the eastern coast; they are more nearly parallel to each other than they are to the more westerly chain, called in South America the Cordilleras of Peru and Chili, and in North America the Rocky Mountains. The Brazilian system of mountains forms an isolated group, of which the highest summits (the Itacolumi and Itambe) do not rise above the height of 900 toises (5755 English feet). The most easterly ridges, which are nearest to the Atlantic, follow a uniform direction from SSW. to NNE.; more to the west the group becomes broader, but diminishes considerably in height. The Parecis hills approach the rivers Itenes and Guaporé, and the mountains of Aguapehi (to the south of Villabella) approach the lofty Andes of Cochabamba and Santa Cruz de la Sierra.
There is no immediate connection between the eastern and western chains,—the Brazilian mountains, and the Cordilleras of Peru,—for the low province of Chiquitos, which is a longitudinal valley running from north to south, and opening into the plains both of the Amazons and of the river Plate, separates Brazil on the east from the Alto Peru on the west. Here, as in Poland and Russia, an often almost imperceptible rise of ground (called, in Slavonian, Uwaly) forms the separating water-line between the Pilcomayo and the Madeira, between the Aguapehi and the Guaporé, and between the Paraguay and the Rio Topayos. The swell of the ground runs to the south-east from Chayanta and Pomabamba (lat. 19°-20°), traverses the province of Chiquitos, which, since the expulsion of the Jesuits, has again become almost a terra incognita, and forms, to the north-east, where there are only detached mountains, the “divortia aquarum” at the sources of the Baures and near Villabella, lat. 15°-17°.
This line of separation of the waters is important in relation to facilities of intercourse, and to the increase of cultivation and civilisation: more to the north (2°-3° N. lat.), a similar line divides the basin of the Orinoco from that of the Amazons and the Rio Negro. These risings or swellings in the plains (called, by Frontin, terræ tumores) might be regarded as undeveloped systems of mountains, which would have connected two apparently isolated groups (the Sierra Parime and the Brazilian mountains) with the Andes of Timana and Cochabamba. These relations, which have been hitherto but little attended to, are the ground of the division which I have made of South America into three basins; viz. those of the lower Orinoco, of the Amazons, and of the Rio de la Plata. The first and last of these are steppes or prairies; the middle basin, that of the Amazons, between the Sierra Parime and the Brazilian group of mountains, is a forest-covered plain or Hylæa.
If we wish to trace, in equally few lines, a sketch of the natural features of North America, let us cast our eyes first on the mountain chain which, running from south-east to north-west, at first low and narrow, and increasing both in breadth and height from Panama to Veragua, Guatimala, and Mexico (where it was the seat of a civilisation which preceded the arrival of Europeans), arrests the general equatorial current of the waters of the ocean, and opposes a barrier to the more rapid commercial intercourse of Europe and Western Africa with the eastern parts of Asia. North of the 17th degree of latitude and the celebrated isthmus of Tehuantepec, the mountains, quitting the coast of the Pacific, and following a more direct northerly course, become an inland Cordillera. In North Mexico, the “Crane Mountains” (Sierra de las Grullas) form part of the Rocky Mountain chain. Here rise, to the west, the Columbia and the Rio Colorado of California; and, to the east, the Rio Roxo de Natchitoches, the Candian, the Arkansas, and the Platte or shallow river, a name which has latterly been ignorantly transformed into that of a silver-promising river Plate. Between the sources of these rivers (from N. lat. 37° 20′ to 40° 13′) rise three lofty summits (formed of a granite containing much hornblende and little mica), called Spanish Peak, James’s or Pike’s Peak, and Big Horn or Long’s Peak. (See my Essai Politique sur la Nouvelle Espagne, 2me édit. t. i. pp. 82 and 109.) The elevation of these peaks exceeds that of any of the summits of the Andes of North Mexico, which, indeed, from the 18th and 19th parallels of latitude, or from the group of Orizaba and Popocatepetl (respectively 2717 toises or 17374 English feet, and 2771 toises or 17720 English feet,) to Santa Fé and Taos, never reach the limits of perpetual snow. James Peak, in lat. 38° 40′, is supposed to be 1798 toises, or 11497 English feet; but of this elevation only 1335 toises (8537 English feet) has been measured trigonometrically, the remaining 463 toises, or 2960 English feet, being dependent, in the absence of barometrical observations, on uncertain estimations of the declivity of streams. As a trigonometrical measurement can hardly ever be undertaken from the level of the sea, measurements of inaccessible heights must generally be partly trigonometrical, and partly barometrical. Estimations of the fall of rivers, of their rapidity and of the length of their course, are so deceptive, that the plain at the foot of the Rocky Mountains, nearest to the summits above spoken of, was estimated, previous to the important expedition of Capt. Frémont, sometimes at 8000, and sometimes at 3000 feet. (Long’s Expedition, vol. ii. pp. 36, 362, 382, App. p. xxxvii.) It was from a similar deficiency of barometrical measurements that the true elevation of the Himalaya continued so long uncertain: but now the resources which belong to the cultivation of science have increased in India to such a degree, that Captain Gerard, when on the Tarhigang, near the Sutlej, north of Shipke, at an elevation of 19411 English feet, after breaking three barometers, had still four equally correct ones remaining. (Critical Researches on Philology and Geography, 1824, p. 144.)
Frémont, in the expedition which he made in the years 1842–1844 by order of the Government of the United States, found the highest summit of the whole chain of the Rocky Mountains to the north north-west of Spanish, James’s, Long’s, and Laramie Peaks. This snowy summit, of which he measured the elevation barometrically, belongs to the group of the Wind River mountains. It bears on the large map, edited by Colonel Abert, Chief of the Topographical Office at Washington, the name of Frémont’s Peak, and is situated in 43° 10′ lat. and 110° 13′ W. long. from Greenwich, almost 5½° north of Spanish Peak. Its height, by direct measurement, is 12730 French, or 13568 English feet. This would make Frémont’s Peak 324 toises (or 2072 English feet) higher than the elevation assigned by Long to James’s Peak, which, according to its position, appears to be identical with Pike’s Peak in the map above referred to. The Wind River mountains form the divortia aquarum, or division between the waters flowing towards either ocean. Captain Frémont (in his Official Report of the Exploring Expedition to the Rocky Mountains in the year 1842, and to Oregon and North California in the years 1843–44, p. 70,) says, “We saw, on one side, countless mountain lakes, and the sources of the Rio Colorado which carries its waters through the gulf of California to the Pacific; and, on the other side, the deep valley of the Wind river, where are situated the sources of the Yellowstone river, one of the principal branches of the Missouri which unites with the Mississippi at St. Louis. To the north-west, rise, covered with perpetual snow, the summits called the Trois Tetons, where the true source of the Missouri itself is situated, not far from that of the head water of the Oregon or Columbia, or the source of that branch of it called Snake River or Lewis Fork.” To the astonishment of the adventurous travellers, they found the top of Frémont’s Peak visited by bees: perhaps, like the butterflies seen by me, also among perpetual snow but in much more elevated regions in the Andes of Peru, they had been carried thither involuntarily by ascending currents of air. I have seen in the Pacific, at a great distance from the coast, large winged lepidopterous insects fall on the deck of the ship, having, no doubt, been carried far out to sea by land winds.
Frémont’s map and geographical investigations comprehend the extensive region from the junction of the Kanzas river with the Missouri, to the falls of the Columbia and to the missions of Santa Barbara and Pueblo de los Angeles in New California; or a space of 28 degrees of longitude, and from the 34th to the 45th parallel of latitude. Four hundred points have been determined hypsometrically by barometric observations, and, for the most part, geographically by astronomical observations; so that a district which, with the windings of the route, amounts to 3600 geographical miles, from the mouth of the Kanzas to Fort Vancouver and the shores of the Pacific (almost 720 miles more than the distance from Madrid to Tobolsk), has been represented in profile, shewing the relative heights above the level of the sea. As I was, I believe, the first person who undertook to represent, in geognostic profile, the form of entire countries,—such as the Iberian peninsula, the highlands of Mexico, and the cordilleras of South America, (the semi-perspective projections of a Siberian traveller, the Abbé Chappe, were founded on mere and generally ill-judged estimations of the fall of rivers),—it has given me peculiar pleasure to see the graphical method of representing the form of the earth in a vertical direction, or the elevation of the solid portions of our planet above its watery covering, applied on so grand a scale as has been done in Frémont’s map. In the middle latitudes of 37° to 43° the Rocky Mountains present, besides the higher snowy summits comparable with the Peak of Teneriffe in elevation, lofty plains of an extent hardly met with elsewhere on the surface of the earth, and almost twice as extensive in an east and west direction as that of the Mexican plateaux. From the group of mountains, which commences a little to the west of Fort Laramie to beyond the Wahsatch mountains, there is an uninterrupted swelling of the ground from 5300 to 7400 English feet above the level of the sea. A similar elevation may even be said to occupy the whole space from 34° to 45° between the Rocky Mountains proper and the Californian snowy coast chain. This space, a kind of broad longitudinal valley like that of the lake of Titiaca, has been called, by Joseph Walker, a traveller well acquainted with these western regions, and by Captain Frémont, “The Great Basin.” It is a terra incognita of at least 128000 square miles in extent, arid, almost entirely without human inhabitants, and full of salt lakes, the largest of which is 4200 English feet above the level of the sea, and is connected with the narrow lake of Utah. (Frémont, Report of the Exploring Expedition, pp. 154 and 273–276.) The last-mentioned lake receives the abundant waters of the “Rock River;” Timpan Ogo, in the Utah language. Father Escalante, in journeying, in 1776, from Santa Fé del Nuevo Mexico to Monterey in New California, discovered Frémont’s “Great Salt Lake,” and, confounding lake and river, gave it the name of Laguna de Timpanogo. As such I inserted it in my map of Mexico; and this has given rise to much uncritical discussion on the assumed non-existence of a great inland salt lake in North America,—a question previously raised by the well-informed American geographer, Tanner. (Humboldt, Atlas Mexicain, planche 2; Essai Politique sur la Nouvelle Espagne, T. i. p. 231, T. ii. pp. 243, 313, and 420; Frémont, Upper California, 1848, p. 9; and, also, Duflot de Mofras, Exploration de l’Oregon, 1844, T. ii. p. 40.) Gallatin says expressly, in the Memoir on the Aboriginal Races in the Archæologia Americana, vol. ii. p. 140, “General Ashley and Mr. J. S. Smith have found the lake Timpanogo in the same latitude and longitude nearly as had been assigned to it in Humboldt’s Atlas of Mexico.”
I have dwelt on the remarkable swelling of the ground in the region of the Rocky Mountains, because, doubtless, by its elevation and extent, it exercises an influence hitherto but little considered, on the climate of the whole continent of North America, to the south and east. In the extensive continuous plateau, Frémont saw the waters covered with ice every night in the month of August. Nor is the elevation of this region less important as respects the social state and progress of the great United States of North America. Although the elevation of the line of the separation of the waters nearly equals that of the passes of the Simplon (6170 French, or 6576 English feet), of the St. Gothard (6440 French, or 6865 English feet), and of the St. Bernard (7476 French, or 7969 English feet), yet the ascent is so gradual, as to offer no obstacle to the use of wheel carriages of all kinds in the communication between the basins of the Missouri and the Oregon; in other words, between the states on the Atlantic Sea Board opposite Europe, and the new settlements on the Oregon and Columbia opposite China. The itinerary distance from Boston to Astoria on the Pacific at the mouth of the Columbia, is, according to the difference of longitude, 2200 geographical miles, or about one-sixth less than the distance of Lisbon from the Ural near Katharinenburg. From the gentleness of the ascent of the high plateau which leads from the Missouri to California and to the basin of the Oregon,—(from the River and Fort Laramie, on the northern branch of the Platte River, to Fort Hall on the Lewis Fork of the Columbia, all the camping places of which the height was measured were from upwards of five to seven thousand, and at Old Park even 9760 French, or 10,403 English feet);—it has not been easy to determine the situation of the culminating point, or “divortia aquarum.” It is south of the Wind River mountains, nearly midway between the Mississipi and the coast of the Pacific, at an elevation of 7027 French, or 7490 English feet; therefore only 450 French, or 480 English, feet lower than the Pass of the great St. Bernard. The immigrants call this point “the South Pass.” (Frémont’s Report, pp. 3, 60, 70, 100, 129). It is situated in a pleasant district, in which the mica slate and gneiss rock are found covered with many species of Artemisia, particularly Artemisia tridentata (Nuttall), asters, and cactuses. Astronomical determinations give the latitude 42° 24′, and the longitude 109° 24′ W. from Greenwich. Adolph Erman has already called attention to the circumstance that the direction of the great chain of the Aldan mountains in the east of Asia, which divides the streams flowing into the Lena from those which flow towards the Pacific, if prolonged on the surface of the globe in the direction of a great circle, passes through several summits of the Rocky Mountains, between the parallels of 40° and 55°. “Thus an American and an Asiatic chain of mountains appear to belong to one great fissure, following the direction of a great circle, or the shortest course from point to point.” (Compare Erman’s Reise um die Erde, Abth. I. Bd. iii. S. 8, Abth. II. Bd. i. S. 386, with his Archiv für wissenschaftliche Kunde von Russland, Bd. vi. S. 671).
The Rocky Mountains which sink down towards the Mackenzie River which is covered a large portion of the year with ice, and the highlands from which single snow-clad summits rise, are altogether distinct from the more westerly and higher mountains of the coast, or the chain of the Californian Maritime Alps, the Sierra Nevada de California. However ill selected the now generally used name of the Rocky Mountains, to designate the most northerly continuation of the Mexican Central Chain, it does not appear to me desirable to change it, as has been often proposed, for that of the Oregon Chain. Although these mountains do indeed contain the sources of Lewis’s, Clark’s, and North Fork, the three chief branches which form the mighty Oregon, or Columbia River, yet this river also breaks through the Californian chain of snow-clad Maritime Alps. The name of Oregon District is also employed politically and officially for the smaller territory west of the Coast Chain, where Fort Vancouver and the Walahmutti settlements are situated, and therefore it is the more desirable not to give the name of Oregon either to the Central or the Coast Chain. This name is connected with a most singular mistake of an eminent geographer, M. Malte Brun: reading on an old Spanish map, “And it is not yet known, (y aun se ignora) where the source of this river” (the river now called the Columbia) “is situated,” he thought he recognised in the word ignora the name of Oregon. (See my Essai politique sur la Nouvelle Espagne, T. ii. p. 314).