The rivers of Asia may be also arranged in four groups, according to the systems of which they form a part.

The Asiatic Section of the Arctic River-System embraces the whole of the rivers which drain the northern slope of the continent. Rising in the mountain-ranges that form the northern buttress of the great central table-land, the three great rivers of Siberia flow through vast plains, which are barren and uncultivated or covered with dense forests, and which become more and more barren as they approach the shores of the Polar Sea, where they form the desolate "Tundras," a vast tract nearly 4,000 miles in length, alternately an irreclaimable swamp or a frozen plain. Perfectly open to the icy blasts from the north, these rivers are frozen over for several months in the year, and flowing, as they do, from warmer to colder regions, their upper courses are liberated from the ice, while their middle and lower courses are still frozen. Hence the periodical floods which inundate this inhospitable region. Except when in flood, the slight fall of the land renders them extremely sluggish, but, as they flow into a frozen ocean, they are not of much use for commerce, although a considerable number of vessels navigate the upper courses of the main streams and their chief tributaries.

The OB (2,500 miles) may be said to rise in the alpine lake of Teleskoi, in the Altai mountain-region. Flowing generally north-west, it receives the Katunia and the Tom, and, lastly, its great affluent-the Irtish, which, according to the ordinary rule of river-nomenclature, should have been called the Obi. The Irtish rises in the Great Altai Mountains, and, after passing through Lake Zaisan, receives two large tributaries-the Ishim, from the Kirghiz Steppe, and the larger stream of the Tobol, from the Ural Mountains. After its junction with the Irtish, the Ob repeatedly divides into several channels, and finally enters the Gulf of Ob by three mouths, which are closed by ice from October to May.

The YENISEI (3,000 miles) is formed by numerous streams which descend from the Altai Mountains, and flows almost due north, for the most part on or near the 90th meridian E. It receives three larger tributaries on its right bank, known as the Upper, Middle, and Lower Tunguska. The Upper Tunguska, or Angara, drains Lake Baikal, the main feeder of which is the Selenga. The upper courses of the main stream and its tributaries are swift torrents, which become sluggish and navigable after entering the plain. The main stream is generally of great breadth, and in the lower part of its course is from 12 to 50 feet deep. Like the other Siberian rivers, the Yenisei is subject to annual floods, and is frozen for many months, but it is, however, regularly navigated during the summer months by steam vessels.

The LENA (2,500 miles) rises in the mountains that skirt the western shores of Lake Baikal, and almost immediately becomes a navigable stream. It flows first north-east as far as YAKUTSK, where it bends north, entering the ocean by several mouths, forming a delta upwards of 100 miles in width. Like the Yenisei, it receives three large tributaries on its right bank,-the Vitim, Olekma, and Aldan. Below its junction with the latter it also receives a considerable river from the west--the Viliui. The current of the Lena, except when in flood, is sluggish, and the river is much navigated during the brief summer of these

high latitudes. Remains of the huge mammoth and other animals now extinct are found embedded on the frozen banks of this Arctic stream, and whole carcases, in almost perfect preservation, are occasionally exposed by the floods.

East of the Lena, and separated from it by a low range of hills, are the basins of the Yana, Indigirka, and Kolyma, all of which have a northerly course through the inhospitable Tundras to the sea.

The Asiatic Section of the Atlantic, or rather Mediterranean, River-System embraces numerous unimportant streams that fall into the Black Sea, the Egean Sea, and the Mediterranean, from Trans-Caucasia and Asiatic Turkey.

Of the Trans-Caucasian rivers the only noticeable one is the Rion, which rises in the Caucasus, and, flowing west past Kutais, enters the sea at Poti. This stream was regarded by the ancients as the boundary between Europe and Asia. The interior plateau of Asia Minor is dry and sterile, and the numerous streams that descend thence to the sea are mere torrents-rapid and unnavigable. The northern slope is drained by the Kizil-Irmak, the Sakaria, and other smaller streams, all of which rise in the interior highlands, and pass through deep narrow valleys and rugged defiles to the sea. The Kizil-Irmak (the ancient Halys) describes a curve more than three times the direct distance from its source to its mouth. Although it is the largest river in the peninsula, its elevated source, the steepness of its bed, and its small volume of water, combine to render it useless for the purposes of navigation. The streams that fall into the Sea of Marmara and the Dardanelles are small and unimportant. Those entering the Ægean Sea are more considerable, and flow through long and (except towards the sea) narrow and fertile valleys, of alluvial formation. On the south, the streams that descend from the southern slopes of the Taurus are necessarily short and rapid. Of these, the Cydnus is the most celebrated. Of the Syrian rivers, the largest is the Orontes, which rises in the Anti-Lebanon, and flows north through a narrow valley (the Cale-Syria of Classical Geography), curving to the west at Antakia (the ancient Antioch), and entering the sea immediately north of Jebel-Okrah, the Mount Casius of antiquity.

The Asiatic Section of the Pacific System is far more important than the American or the Australian sections, both in the number and magnitude of its rivers, which rise far inland among the mountains that buttress the great central plateau of Asia. The principal streams are the Amur, forming, for the most part, the boundary between the Russian and Chinese dominions; the Hoang-ho, Yangtse-kiang, and Si-kiang, in China; the Song-ka, Mekong, and Menam, in Further India.

The AMUR (2,500 miles) is formed by the confluence of two streams, both of which rise in the mountains south-east of Lake Baikal. Below their junction, the now considerable river breaks through the Khinghan Mountains, and flows eastwards, receiving several affluents from the Yablonoi Mountains on the north, and on the south the Sungari (the great river of Manchuria) and the Ussuri. After its junction with the latter stream, the Amur bends north, and enters the sea about twenty miles below NIKOLAIEVSK. This fine river is navi. gable by light steamers to within 300 miles of its source, but it is frozen over from November to June.

Both the great rivers of China, the Hoang-ho and the Yang-tse kiang, issue from the mountain-regions of Eastern Tibet; within China, their basins are separated by the latitudinal chain of the Pe-ling Mountains. The HOANG-HO (2,600 miles) is extremely tortuous in its upper course-flowing first south east, then bending north-east to the Inshan Mountains, along the base of which it runs east for about 100 miles. It then turns due south, cutting for the fourth time through the "Great Wall "-that useless monument of Chinese industry. Being joined by the Wei-ho, it again turns east, and near Kai-fong turns north-east, and enters the Gulf of Pe-che-lee. Before the year 1854, the Hong-ho entered the Yellow Sea about 100 miles north of the mouth of the Yang-tse-kiang. In that year, however, it burst through the artificially-formed mounds which the continued deposit of ages had rendered necessary for the confinement of its channel, and it now flows in the former bed of the Ta-tsing-ho-its present mouth being 300 miles north of its former embouchure. Off the latternow dry-its sands stretch seaward for upwards of a hundred miles, rendering it dangerous for large ships to approach that portion of the coast. In the course of this disastrous change, it destroyed a large portion of the Imperial Canal-the great highway for the conveyance of grain to PEKIN. According to native accounts, this river has changed its lower course no less than nine times during the last 2,500 years. It is of little value for navigation; its current is rapid; and it is also shallow, and subject to sudden changes in depth.

Vastly more important to the teeming millions of China is the YANG. TSE-KIANG (3,200 miles), which, leaving the mountains of Western China by a deep gorge, turns east, watering the fertile and densely-peopled alluvial plain between the Pe-ling Mountains on the north and the Nan-ling Mountains on the south, from both of which it receives many large affluents. At HANKAU, 700 miles from the sea, it is fully a mile wide, while above NANKING its normal width is four miles, expanding in flood to twenty miles. Large steamers easily ascend this noble stream to I-CHANG, 1,200 miles from the sea; smaller steamers have forced their way 600 miles higher to the new port of CHUNGKING, the commercial capital of Western China, while junks and boats can proceed some hundreds of miles further. The vast quantity of sediment which the Yang-tse brings down causes frequent changes to take place in the islands and banks that occur in its bed, and the sea adjacent to its estuary is being gradually silted up. The Hoang-ho also carries down an immense amount of mud, which will in time fill up the already shallow Gulf of Pe-chi-li.

The third great river of China is the SI-KIANG (900 miles), the basin of which is divided from that of the Yang-tse-kiang by the Nan-ling Mountains. This river enters the China Sea by a wide estuary, known as the Canton River. It is an important commercial highway, being ascended by the largest vessels to the great port of CANTON, and by smaller craft for upwards of 300 miles inland. Only two of the great rivers of the Indo-Chinese Peninsula belong to the Pacific Basin-namely, the Mekong (1,650 miles) and the Menam (900 miles). The Mekong rises in Tibet and flows through the highlands of Yunnan, not far from the banks of the Yang-tse-kiang; it then traverses Eastern Burma and the great alluvial plains of Eastern Siam and Cambodia, and enters the sea by numerous mouths, which form an extensive delta. The better known stream of the Menam flows from the northern frontiers of Siam, first through the hill country of the semi-independent Shan tribes, and then through the great valley of Siam, entering the head of the Gulf of Siam by three mouths, about 20 miles below the busy port of BANGKOK. Both the Menam and the Mekong, like the Nile, overflow their banks, and thus fertilize the country through which they flow.

The Asiatic Section of the River-System of the Indian Ocean comprises some of the largest rivers of the globe, such as the Irawadi, Brahmaputra, and Ganges, which fall into the Bay of Bengal; the Indus, flowing into the Arabian Sea; and the Tigris and Euphrates, which unite their waters into one stream-the Shat el Arab-before debouching into the Persian Gulf. Of the smaller streams included in this section, the principal are the Salwin and Sitang, flowing into the Guf of Martaban; the Mahanadi, Godavari, Kistna, and Cauveri, draining the eastern slope of Peninsular India; and the Tapti and Narbada, flowing into the Gulf of Cambay. Between the Indus and the Shat el Arab, a few unimportant rivers enter the sea, but the whole circuit of the Arabian coast is unbroken by the outlet of any permanent stream.

Both the Salwin and the Irawadi ise in the mountains to the north of Burma, and flow almost due south through Burma to the sea. The Salwin (1,200 miles) is navigable for a considerable distance inland, but it is not so well known as the Irawadi (800 miles), which is regularly traversed by British steamers as far as BHAMO, 700 miles from the sea. Below Ava, this noble stream varies in width from one to four miles, and, 70 miles from the sea, it divides into numerous channels, ultimately discharging its waters by fourteen mouths. The enclosed delta is much more extensive than that of the Nile, and is covered with low jungle, magnificent forests, or productive rice-fields.

The BRAHMAPUTRA (1,680 miles), the most easterly of the three great rivers which derive their chief supplies from the Himalayas, rises under the name of the Sanpu in the vast glaciers on the northern slope of the main range, whence also issue the Indus and the Sutlej. The Sanpu, after an eastwardly course of several hundred miles, turns suddenly south, breaks through the mountains, and emerges on the plain under the name of the Dihong. Being joined by a large river which, until the discovery of the Sanpu, was considered the main stream, it flows west through Assam, then, curving south through the plains of Bengal, it effects a junction with the eastern outlet of the Ganges. The Brahmaputra, notwithstanding its somewhat rapid current and occasional obstructions, is generally navigable, both in Tibet and India. In Assam, its channel is studded with islands, and bordered by numerous ana-branches; in Bengal, it is a magnificent stream, four or five miles in width, and with a larger volume than any other river of southern Asia. The whole of the valley of the Brahmaputra, south of the Himalayas, is periodically inundated; the river rising frequently to a height of 30 to 40 feet above its normal level.'

But the Brahmaputra, notwithstanding its superior length and volume, is far less important than the GANGES (1,500 miles), the work done by which "as the water-carrier and fertilizer of the densely-populated provinces of Northern India, from its source in the Himalayas to its mouth in the Bay of Bengal, entitles it to rank as the foremost river on the surface of the globe, and fully excuses the affectionate reverence and divine honours paid to it by the Hindus. "A great river like the Ganges has three distinct stages in its life from its source to the sea. In the first stage it dashes down the mountain sides, cutting out for itself deep gullies in the solid rock, and ploughing up glens and ravines on

1. It is worthy of remark that the Brahmaputra and the Ganges rise near each other, flow at first in opposite directions until they are 1,200 miles apart, then suddenly change their courses, rapidly ap

proximate to each other, and at length unite their waters in a common channel at a point about 40 miles from the sea.

its way. The second stage is where it emerges from the mountains on to the plain, running then more peaceably along the valleys, and seeking out for itself the lowest levels. Here it receives the mud and drainage of the country round, absorbs tributaries, and rolls forward with an ever-increasing volume of water and silt. Finding its speed checked by the equal level of the plains, and its bed raised by its own silt, it splits out into channels, like a jet of water suddenly obstructed by the finger, or a jar of liquid suddenly dashed upon the floor. Each of the channels thus formed throws out in turn its own channel to right and left. In the case of the Ganges, the country which these many offshoots enclose forms the delta of Bengal."

Tracing briefly the course of this great river, we find that, after winding through the rugged mountain-region, it breaks through the last of the subHimalayan ranges, the Siwalik Hills, and enters the plain at HARDWAR; it then flows south-east, parallel to its first great affluent, the Jumna, which, rising in the Himalayas, receives important accessions from the Aravalli Hills and the Vindhya Mountains, and joins the main stream at ALLAHABAD. The Ganges then winds in an easterly direction, receiving from the south the Sone, and, from the Himalayas on the north, the Gumti, Gogra, Gandak, and Kusi.

Below its junction with the Kusi, the Ganges turns south, and at a distance of 220 miles from the sea, divides into two great arms-the main branch retaining the name of Ganges, and bending south-east to its junction with the Brahmaputra. The western branch, known as the Hugli, though inferior in width and volume, is commercially more important, and forms the ordinary channel of entrance. The triangular track enclosed between these two branches is intersected by a labyrinth of channels, "so various in point of width, that a vessel has at one time her masts almost entangled in the trees, and at another sails uninterrupted on a capacious river." The upper portion of the Gangetic Delta is fertile and well-cultivated; the lower parts form the pestilential "Sundarbans," covered with jungle, and infested with tigers.

In spite of unfailing sources of supply, evaporation is so active in the great plain, that the volume of the river perceptibly decreases as it approaches the sea, except during the floods, when it overflows its banks, and inundates the adjoining plain. When in flood, it also frequently changes its channel; for instance, Rajmahal, formerly on the banks of the river, is now more than seven miles distant. Large sea-going vessels ascend the Hugli as far as CHANDARNAGAR, a few miles north of CALCUTTA, and the main stream is navigable by small steamers to CAWNPUR, and thence by canal to HARDWAR, 1.300 miles from the sea. Some of its great tributaries are also navigable-the Jumna and connected canals afford a practicable waterway for vessels of light draught for 200 miles above DELHI. Both the Brahmaputra and the Ganges bring down a vast amount of sediment, which not only adds to the delta, but is gradually silting up the head of the Bay of Bengal.

The Brahmaputra and the Ganges derive their waters not only from the snows of the Himalayas, but also from the monsoon rains. The numerous streams that drain the Deccan, on the contrary, are supplied entirely by the monsoon rains, and are thus subject to comparatively greater variations in depth and volume. The line of elevation that marks the edge of the Deccan being continuous on the western side only (the Eastern Ghats being merely a series of detached elevations), all the great rivers of Peninsular India, with the exception of the Narbada and the Tapti, flow eastwards into the