Himalaya Mountains , (Sanskrit, hima, snow, and alaya, abode), a mountain chain of Asia, bordering upon India on the north, and separating it from Thibet. It is limited on the east by the Brahmapootra, and on the west by the Indus. Both these rivers, as well as the Ganges and the Sutlej, are now considered to spring from the snow fields of the Juwahir or Nanda Devi in the middle Himalaya, and those of the Kailasa in Thibet, to the north, between lon. 80° and 82° E. and lat. 30° and 31° N. The configuration of the earth is such at this point, that from the N. W. foot of the Kailasa the Indus flows N. W. along an enlcosed valley, its deep-cut channel about 100 m. distant from the Himalaya to the south, until it passes through the chain about lat. 35° 40' N., Ion. 74° 40' E., and from that point descends S. to the Arabian sea. On the other hand, the Brahmapootra (called at its origin the Dzang-bo-tzin or Sanpo) rises on the S. E. foot of the Kailasa, flows S. E. and E., then in lat. 27° 45' N., Ion. 95° E., turns round the depressed hills on its right bank, and pursues its rapid and winding course to the bay of Bengal. Within the limits thus formed by nature the Himalaya measures in its curvings 2,000 m. in length, with a mean breadth of 180 m.

The mighty ridges which rise above the plains of Thibet, and run parallel to the Himalaya from N. W. to S. E., compel both the Indus and Brahmapootra to flow from the divide of the Kailasa in a direction conformable with the enclosing mountain walls, until the increasing stream of the Indus is turned southward by the spurs sent down into its bed by the Karakorum and Hindoo Koosh, while the accumulated and rapid waters of the Brahmapootra are also turned southward and westward by the snowy masses which rise abruptly on its left bank to the east and south, where the eastern Himalaya terminates. The division of the chain into western, middle, and eastern Himalaya is founded upon like natural and obvious reasons. The western Himalaya is that portion drained by the five rivers of the Punjaub, from the Indus on the west to the Sutlej on the east, their united waters being conveyed to the ocean by the former. The middle Himalaya is that portion which is drained by the Ganges, and limited on the west by the mountain masses which overlook the left bank of the Sutlej, and in which the Jumna (Jumnotri) has its manifold sources, and on the east by the course of the Teesta in Sikkim. It comprises the territory of Nepaul. Finally, the eastern Himalaya is drained by the Brahmapootra, and is all comprised within the little-explored country of Bhootan, from the wall of stupendous peaks which runs southward above the left bank of the Teesta, to where the Brahmapootra, under the local appellation of Dihong, enters Assam. The axis of this great mountain mass follows the line of watershed, and can by a careful inspection of a good map be drawn from point to point, where the streams originate which flow from the Himalaya northward into the Indus, the Sutlej, and the Brahmapootra, and those which empty southward into these same rivers and the Ganges. The axis thus traced along the line of watershed will be found to be also the line of mean greatest elevation, although the highest peaks do not happen to be on the axis.

The direction of the secondary chains is often perpendicular to the main chain, oftener oblique to it, and not unfre-quently parallel, while enclosing within the inosculating ridges valleys of great length. This fact, and the height of the summits on so many of them, and the duration of the heavy snow with which they are mantled, have led local observers to confound these snowy ridges with the axis of the chain itself. The plains of India at the E. extremity of the Himalaya are but little elevated above the level of the sea; at the foot of the mountains they may be 350 ft. above this level in the meridian of Calcutta, and in the Punjaub toward the W. extremity of the range the elevation may be 1,000 ft. From these plains the view of the mountains is for the greater part of the time obscured by the vapors falling upon the southern ridges; but after the cessation of the S. E. monsoons the snowy peaks are sometimes seen at a distance of about 200 m., at an angle of elevation of only about 1° above a horizontal line.

On approaching nearer to the chain, the distant peaks are lost to view behind the nearer wooded ones, and glimpses are rarely obtained that impress one with the vast magnitude and stupendous height of the chain. - Dr. Joseph D. Hooker, author of "Himalayan Journals," distinguishes four parallel longitudinal belts of country in the structure of these mountains. The lowest on the S. side extends from the plains of India to regions where snow is met with in winter. It is from GO to 100 m. in width, ranging it may be from 5,000 to 8,000 ft. mean elevation, with peaks 13,000 to 14,000 ft. high. The lower portions are tropical, the upper temperate. It is cut up by ravines, but is not particularly precipitous. Beyond this ranges the second or snowy belt, that of the highest peaks 40 to 50 m. broad, its surface rugged and precipitous, with summits rising frequently to 20,000, some to 25,000, and a few even to 28,-000 ft. above the level of the sea. Some of the rivers flow in deep gorges across this belt, their beds not more than 3,000 ft. above the sea level. The mean elevation is probably under 13,000 ft.

To this succeeds the central belt or axis of the chain, from 20 to 30 m. broad, its mean elevation perhaps 18,000 ft., at least in the middle Himalaya, and the main ridge or watershed seldom below 17,000 ft. except at the extremities; the surface is rocky and often precipitous. The northern belt is a region of mountains and valleys little explored, constituting the slope toward Thibet. Its climate is temperate, but of excessive vicissitudes, subject to drought, and the hills lack the luxuriant forest growth which covers those of corresponding elevations upon the other side. Skirting the southern foot of the Himalaya lies a tract of part forest, part jungle and marsh, from 10 to 20 m. in breadth. It is due to the humidity of the climate and to copious springs, as well as to the fact that this belt of pestilential waste is slightly depressed below the level of the plain to the south of it, thus allowing the collected waters to stagnate, and to produce beneath the tropical sun a rank and dense vegetation.

This tract is called Terrai or Tar-ragani, "passage through," and its outer habitable region Kadir. It gradually narrows away as it gains in height toward the central portion of the chain, and disappears W. of the Sutlej. Back of this tract Dr. Hooker says that "the mountains rise more or less suddenly, though seldom in precipices." They are reached sometimes by difficult paths that follow up the narrow and pestilential gorges of the rivers, or more commonly by the roads that ascend into the healthier atmosphere upon the summits of the secondary ridges. These ridges present to the traveller toward the axis of the chain a succession of ascents and descents; in each valley his progress is interrupted by a stream tributary to the nearest river to the right or left, or by the deep gorges of the larger branches themselves; and upon the slopes his course is impeded by forests and rocky precipices. No plain anywhere opens out before him; and during the warmer portion of the year cloud and fog shut in the view from the commanding points he reaches.

So rugged are the mountains that 12 or 14 days are usually required for the journey of about 100 m. to the axis of the chain upon the main routes from India to Thibet, The difficulties thus opposed to exploration or settlement are not compensated by the presence either of great mineral wealth or of large tracts favorable to culture. On the other hand, it would be unjust to adopt the descriptions of occasional travellers. It takes a long time, even for one acquainted with mountain regions, to trace correctly the various positions of ridges and spurs, of valleys and river courses, in any large area of an alpine aspect; but this difficulty is nowhere so formidable as among the huge masses and labyrinthine windings of the Himalaya. By most travellers the secondary ridges on the S. side, particularly of the E. portion of the chain, are represented as spurs leaving this at right angles, though as seen from the plains at a distance they present the appearance of longitudinal ridges. The strike of the rocky formations of which the chain is composed - the metamorphic slates and granitic rocks of the central portion, and the Silurian sandstone of the southern ridges - is described as everywhere with the general course of the mountains, thus suggesting a resemhlance of the system to that of the Appalachians of the United States in its parallel ridges and valleys, though this feature on the S. side of the Indian mountains may be obscured by the effect of rapid and excessive drainage. - The statements as to the relative amount and duration of the snow upon the N. and S. slopes of the chain have led to much controversy.

The authorities generally concur in representing that milder temperatures prevail upon the N. side than at corresponding heights on the opposite side. The two Gerards place the line of perpetual snow on the S. side at 12,981 ft., and on the N. at 16,620. Lieut. Strachey, extending his observations over a district between Ion. 77° and 81°, where heights covered with perpetual snow are found over a belt of 35 m. in width between lat. 30° and 32°, concluded that the snow line on the Thibetan side is 18,-500 ft. above the sea, and on the Indian side 15,500. On the S. slope grain is cultivated with difficulty at 10,000 ft., while on the other side good crops are raised at 16,000 ft. It grows even at 18,544 ft., as seen by Capt. Gerard. This is more than 1,200 ft. higher than the snow line in the equatorial Andes. The belt constituting the watershed is described as excessively cold, bleak, and dreary, but in great part free from snow. This is no doubt owing to the rain clouds being deprived of their moisture as they are swept from the bay of Bengal over the secondary ridges, upon which it is in part precipitated in rain and the remainder in snow upon the higher peaks.

But the cause of the milder temperature is not so obvious. - The highest peaks are not found along the line of highest mean elevation, but for the most part they are S. of it, rising in scattered groups from the secondary ridges. Of several of these groups E. of Sikkim little is known, except that as seen from a distance they appear to reach heights of 23,000 to 25,-000 ft., or perhaps more. North of Sikkim is a noted group of immense peaks, among which stands preeminent Kintchinjunga, 28,156 ft. (Petermann), or 28,178 ft. (Hooker), in lat. 27° 42', Ion. 88° 11'; and one degree further east Chumulari, 23,946 ft, (P.), or 23,929 ft, (II.). Upon the same parallel, in Ion. 85° 58', stands Mt. Everest, believed to be the highest summit on the globe, having, according to the survey of Col. Andrew Waugh, an altitude of 29,002 ft, Its English appellation is derived from the name of a distinguished officer of the Indian survey. In the Nepaulese its name is Gauri-sankar; by the people of Thibet it is called Chingofanmari. Mr. Hodgson had incorrectly given to it the name Deodunga or Deodhunga, which was that of a peak near by of comparatively small elevation.

Dhawalagiri, in lat. 28° 42', Ion. 83° 32', formerly estimated at 28,000 ft,, is rated by Col. Waugh at 26,826. From the W. extremity of Nepaul to the passage of the Indus through the chain, no fewer than 50 peaks are enumerated, the heights of which range between 19,500 and 25,749 ft., which latter is the height of Nanda Devi in Kumaon, drawn by Heber as a snowy spire, its sides sloping at an angle of 70° with the horizon, and rising far above the similarly snow-clad summits around. Every 12th year the natives make a pilgrimage to this mountain, and the few who succeed in reaching the spot hold a religious festival at a point below the inaccessible summit. The mean height of the central portion along the western Himalaya is estimated at 20,000 ft.; and the passes sometimes cross at heights of 18,000 to 19,000 ft. - The lakes occurring in the Himalaya are few in number, and not of very great extent; the only important ones are on the N. side | of the axis, and are the sources of the branches of the Indus, Sutlej, and Sanpo. Some of these are salt. The largest are from 20 to 30 m. in length.

The Wullur lake in Cashmere, 5,000 ft. above the sea, is a sheet of water 21 m. long E. and W., and 9 m. broad, formed by the spreading out of the river Jhylum, the only instance on the whole range of a river thus expanding into a lake. The rivers are fed during the summer by copious rains brought up by the S. E. monsoons, which sweep over the bay of Bengal, and, reaching the eastern Himalaya in April, gradually progress westward. The whole S. side of the chain by midsummer is enveloped in clouds and mists. In September they begin to clear off in the western divisions, but in the eastern the rains are not over till October or November. In the winter an upper current of S. W. winds brings new supplies of moisture, which falls in snow upon the higher mountains, and there is in the more humid provinces a short rainy season about the close of the year. The outer ranges receive the most of the rain. Dr. Hooker estimates the fall in Sikkim to amount to 120 in. in the year at 7,000 ft. elevation, and to gradually decrease to 10 in. at 19,000 ft. The river courses to the S. are thus much larger and more numerous than those upon the N. side of the chain.

In their upper portions their descent is comparatively gentle, but further down they run with great rapidity, and generally in deep and almost inaccessible ravines; yet they rarely form cascades of any grandeur. Fish of the carp kind abound in them from the plains to 15,000 ft. elevation, except at heights between 5,000 and 10,000 ft. Those of eastern Thibet especially swarm with fish at elevations from 10,000 to 14,000 ft. Glaciers are numerous in the more elevated portions of the mountains, but are wasted away before they reach the lower valleys. Deposits of bowlders and extensive moraines, found in all the valleys at heights exceeding 8,000 or 9,000 ft., indicate that the glaciers formerly reached 6,000 ft. below their present limits. Volcanoes are entirely wanting throughout the range, and there are no evidences of extinct ones. Hot springs are frequently met with at heights from 10,000 to 18,000 ft., their temperature ranging from 100° to 130° F. - The geological formations through the most elevated portions of the range are principally metamorphic slates alternating with granitic belts. They form the loftiest peaks; and against them rest strata of the Silurian period. The formations range with the chain, and are seen usually dipping toward its axis.

In Kumaon rocks of the oolitic formation succeed to the Silurian, and in some of the larger river valleys, at elevations of 15,000 ft., are found tertiary beds with fossils referring them to the miocene period. Among them are specimens of extinct species of the horse, rhinoceros, elephant, hippopotamus, etc. Strata containing marine shells occur at an elevation of 10,000 ft. Fresh-water pleistocene deposits have been found by Dr. Thomson in the extreme western Himalaya of Thibet, on the flanks of mountains far above the present level of the rivers and hikes. The mineral productions are of little importance. Gold is found in eastern Thibet, but the Chinese government prevents its being worked to much extent. In Koonawur, a district at the passage of the Sutlej through the chain, are mines of specular iron ore, which have been long worked by horizontal excavations, extending sometimes half a mile into the mountains. The ore is converted into wrought iron by the natives, who make of it sabres, knives, and hatchets, the best metal being known as that of the locality called Sheel. Copper ores too are found here, and also in Nepaul and Sikkim; but they are not worked. - The vegetable productions in the lower portions of the mountains are those of the tropics.

They reach up to the height of 6,000 or 7,000 ft. in the humid central portions of the range, and in the extreme western to 3,000 or 4,000 ft. In the deep gorges of the rivers are plantains, palms, and tig trees; above are magnolias and laurels; to these succeed oaks, chestnuts, birches, etc.; still higher are pine forests, then rho-dodendra and the scanty alpine growth. All these products of the colder portions are recognized as European forms. These indeed begin to appear as the tropical plants give way to those of temperate climes; and at heights from C,000 to 12,000 ft. are seen species of oak, maple, ash, cherry, poplar, hornbeam, juniper, willow, pine, and many other of familiar names, some of which are identical with the species of Europe and America. The grains, garden fruits, and vegetables cultivated in the upper portions of the mountains arc very similar to those of northern Europe. In the state of Bussaher, of which Koonawur is a province, grapes are extensively cultivated, and tea is produced as an article of commerce.

The distribution of the fauna is similar to that of the flora: tropical forms in the lower regions, among which are found tigers, leopards, buffaloes, the rhinoceros, elephants, etc.; in the upper districts European types predominate, mixed with Chinese and Japanese forms to the eastward, and partaking in the alpine districts of the Siberian character. - The inhabitants constitute many tribes and nations, of Hindoo or Mongolian race. Those of all the valleys above 8,000 ft. elevation are Thibetans, in whom the Aryan is more or less intermixed with the Mongolian. The English have established many stations at points situated from (i,000 to 8,000 ft. above the sea, where they find a healthy atmosphere and a climate like that of England; and they anticipate the time when the habitable portions of the Himalaya will be peopled by their own colonists and their descendants. Dr. Hooker names the following as the most important of these hill sanataria, as he calls them : Darjeeling, elevation 7,000 to 8,000 ft., in Sikkim; Nyni Tal, 6,000 to 7,000 ft., and Almora, 5,000 to 6,000 ft., in Kumaon; Ma-suri, 6,000 to 7,000 ft., in Gurwhal; Kangra, 7,000 to 8,000 ft., in the Beas valley; Murree, 7,000 to 8,000 ft., between the Indus and Jhy-lum; and Simla, 7,000 to 8,000 ft., in the Pun-jaub, near the Sutlej river, a favorite resort for Europeans, being usually the residence of the governor general during a portion of the hotter months. - Among the more distin-. guished explorers of the Himalaya mountains are Adolf Schlagintweit, who was murdered in August, 1857, while engaged in his investigations, and his brothers Hermann and Robert. They demonstrated the correctness of Humboldt's view that there was not the least connection between the Kuenlun and Kara-korum ranges and the Himalaya range, each of them being in tact an independent chain.

The following are some of the many important works relating to this chain : the "Himalayan Journals" of Dr. J. I). Hooker; numerous papers in the "Asiatic Researches" and the journal of the Asiatic society of Calcutta; Humboldt's Asie Centrale; Bishop Heber's "Journal;" "Western Thibet," by Capt. H. Strachey; Thomson's ""Western Himalaya;" Reisen in Hochasien, by H. Schlagint weit; and the publications of the trigonometrical survey of India.

Mount Everest, seen from Darjeeling.

Mount Everest, seen from Darjeeling.