Page:Encyclopædia Britannica, Ninth Edition, v. 24.djvu/303

VOLGA 279 it is very difficult to say which of these ought to be regarded as the real source. Lake Seliger was formerly so considered ; but at present that distinction is given to a small spring trickling into a wooden trough from beneath a small chapel in the midst of an extensive marsh to the south of Seliger (57 10 N. lat. ). The honour has also been claimed of late, not without plausibility, for the Ruua rivulet. 1 Recent exact surveys have shown those marshes to be no more than 665 feet above sea-level. The stream first traverses several small lakes, all having the same level, and, after its junction with the Runa, enters Lake Volgo. A dam recently erected a few miles below that lake, with a storage of 350 million cubic yards of water, makes it possible to raise the level of the Volga as far as the Sheksna, thus rendering it navigable, even at low water, from its 65th mile onwards. Unlike most other great rivers, the Volga has thus no "upper course" among the mountains. From the Valdai plateau, however, its descent is rapid, until at Tver its level is only 420 feet. Before reaching this point it has received numerous small tributaries, so as to be already 300 yards in breadth, with a volume of more than 4000 cubic feet per second, and a minimum depth at low water of 19 inches. The Tvertsa is connected by the Vyshniy-Volotohok Canal with the Tsna, a tribu tary to the Msta and Volkhoff, which flows to Lake Ladoga, the first of the three systems of canals which, as already remarked, have removed the commercial mouth of the Volga to the Baltic. From Tver the Volga is regularly navigated, although not without some difficulties on account of the shallows and sandbanks. It flows north-east along a broad valley to join the Moioga and the Sheksna, two important tributaries connected by the Tikhvinsk and Mariiiisk Canals with the tributaries of Lake Ladoga. Of these two systems the latter is much the more important, and the town of Rybinsk, at the mouth of the Sheksna, has therefore become the chief port of the upper Volga. From its junction with the Sheksna the Volga flows with a very gentle descent towards the south-east, past Yaroslavl and Kostroma, along a broad valley hollowed to a depth of some 150 and 200 feet in the Permian and Jurassic deposits. In fact, its course is through a succession of depressions formerly filled with wide lakes, and connected by links. When the Volga assumes a due south-east direction it is already a large river (8250 cubic feet per second, rising occasionally in high flood to as much as 178,360 cubic feet); of its numerous tributaries, the Unzha (365 miles, 330 navigable), from the north, is the most important. The next great tributary is the Oka, which comes from the south west after having traversed, on its course of 920 miles, all the Great Russian provinces of central Russia. It rises in Orel among hills which also send tributaries to the Dnieper and the Don, and receives on the left the Upa, the Jizdra, the Ugra (300 miles), navigable up to Kozelsk, the Moskva, on which steamers ply up to Moscow, the Klyazma (395 miles), on whose banks arose the Middle Russian principality of Suzdal, and on the right the navigable Tsna (255 miles) and Moksha. Every one of these tributaries is connected with some important event in the history of Great Russia, and the drainage area of the Oka is a territory of 97,800 si|uare miles. It has been maintained of late that, of the two rivers which unite at Nijni-Novgorod, the Oka, not the Volga, is the chief; and the fact is that both in length (818 miles) and in drainage area above the junction (89,500 square miles), as well as in the aggregate length of its tributaries, the Volga is the inferior. But, on the other hand, the Volga contributes on the whole the largest volume of water, although in flood the Oka here also has the advantage. At its junction with the Oka the Volga enters the broad lacus trine depression (see RUSSIA) which must have communicated with the Caspian during the Post-Pliocene period by means of at least a broad strait. Its level at low water is only 190 feet above that of the ocean. Immediately below the junction its breadth ranges from 350 to 1750 yards, and even at the lowest water (in 1873) it had a minimum depth of 5^ feet. The valley, which is nearly 7 miles wide, but at several places is narrowed to less than 2 miles, shows evident traces of having originated from a succession of elongated lakes, the shores of which bear numerous traces of the dwellings of prehistoric man from the Stone Age. There are many islands which change their appearance and position after each inundation. On the right it is joined by the Sura, which drains a large area and brings a volume of from 2700 to 22,000 cubic feet of water per second, the Vetluga (465 miles long, of which 365 are navigable), from the forest-tracts of Yaroslavl, and many smaller tributaries ; then it turns south-east and descends to another lacustrine depression, where it receives the Kama below Kazan, 300 miles below its junction with the Oka, and only 110 feet above the sea. Remains of molluscs still extant in the Caspian occur extensively throughout this depression and up the lower Kama. The Kama, which brings to the Volga a contribution ranging from 52,500 to 144,400 cubic feet and occasionally reaching even 515,000 cubic feet per second, might again be considered as the 1 Ragozin, The Volya, St Petersburg, 1881, 3 vols. (Russian), summarized in Hoskoschny s Die Wohja und ihre Zujliisse, Leipsic, 1887. more important of the two rivers. It rises in Vyatka, takes a wide sweep towards the north and east, and then flows south and south west to join the Volga after a course of no less than 1120 miles. A great number of important rivers join it: the AVishera, coining from the depth of the forest region ; the Kosva, so important for the export of metallic wares from the Ural works; the Tchusovaya (430 miles), which receives the Sylva and connects the Ekaterinburg mining district with central Russia; and finally the Byetaya (800 miles), which, together with the Ufa, its tributary, waters the fertile lands of the Bashkirs, rapidly being settled now by the Russians. A territory larger than France is thus brought into connexion with the great artery of Russian industrial life. Along the next 738 miles of its course the Volga now from 580 to 2600 yards wide flows south-south-west, with but one great bend at Samara. At this point, where it pierces a range of limestone hills, the course of the river is very picturescpue, fringed as it is by high cliffs which rise about 1000 feet above the level of the water (which is only 54 feet above the sea at Samara). Along the whole of the Samara bend the Volga is accompanied on its right bank by high cliffs, which it is constantly undermining, while wide lowland areas extend on the left or eastern bank, and are intersected by several old beds of the Volga. At SAKATOFF (q.v.) the cliffs are being undermined so rapidly that a broad beach now separates the chief channel of the river from the city. Very few streams of any importance join the Volga in this part of its course. Still, at Ekateriuenstadt, a few miles above Saratoff, the volume per second for the two years 1884 and 1885 appears to have been as much as 384,000 cubic feet. In flood 1,427,000 cubic feet per second has been recorded (Boguslavskiy). In the lower portion of this section the Volga has already passed below sea-level (58 feet below at Tsaritsyn). At Tsaritsyn the Volga reaches its extreme south-western limit, where it is separated from the Don by an isthmus of only 40 miles in width. The isthmus is too high to be crossed by means of a canal, but a railway at Duboifka brings the Volga into some sort of connexion with the Don and the Sea of Azoff. At Tsaritsyn the river takes a sharp turn in a south-easterly direction towards the Caspian ; it enters the Caspian steppes, and some 50 miles below Tsaritsyu sends off a branch the Akhtuba which accom panies it for 330 miles before falling into the Caspian. Here the Volga receives no tributaries ; its right bank is skirted by low hills, but on the left it spreads freely, joining the Akhtuba by many branches when its waters are high, and Hooding the country for from 15 to 35 miles. The width of the main branch ranges from 520 to 3500 yards, and the depth exceeds 80 feet. The delta proper begins 40 miles above Astrakhan, and the branches subdivide so as to reach the sea by as many as 200 separate mouths. Below Astrakhan navigation is difficult, and on the sand-bars at the mouth the maximum depth is only 12 feet in calm weather, a depth increased or diminished by a few feet according to the force and direction of the wind. The figures given above, showing as they do how immensely different in volume is the river at different periods, help to indicate the greatness of the changes which are constantly going on in the channel and on its banks. Not only does its level occasionally rise in flood as much as 50 feet and cover its low-lying banks for a distance ranging from 5 to 15 miles; even the level of the Caspian is considerably affected by the sudden influx of water brought by the Volga. The amount of suspended matter brought down is of course correspondingly great ; and, were it not for the action of the wind in driving back masses of water at the mouth of the Volga and thus filling up lakes where the mud is deposited, the bar at Astrakhan would soon become so silted up as completely to pre vent navigation. All along its course the Volga wastes its banks with great rapidity ; towns and loading ports have constantly to be shifted farther back. The shoals and shallows are continually changing, and maps of the river made for a series of consecutive years are of the greatest interest to the physical geographer. The question as to the gradual desiccation of the Volga, and its causes, has often been discussed, and in 1838 a committee which included Karl Baer among its members was appointed by the academy of sciences to investigate the subject ; no positive result has, however, been arrived at, principally on account of the want of regular measurements of the volume of the Volga and its tributaries, measurements which began to be made on scientific principles only in 1880. Still, it may be regarded as established that during the last thirty years new shallows have appeared in the upper Volga, and the old ones have increased in size ; while if we go back two or three centuries it is indisputable that rivers of the Volga basin which were easily navigable then are now hardly accessibl- to the smallest craft. The desiccation of the rivers of Russia has been often attributed to the steady destruction of its forests. But it is obvious that there are other general causes at work much more important, causes to which the larger phenomena of the general desiccation of all rivers of the northern hemisphere in the deserts of Siberia and Turkestan, as well as in Russia, must be attributed.

The gradual elevation of the whole of northern Russia and Siberia,