Page:Encyclopædia Britannica, Ninth Edition, v. 19.djvu/198

Rh 188 PLATE [RIVER. ing hard from the land and at another a sea wind driving the ocean before it, the ordinary levels and currents are often violently disturbed. The general slope of the sur face may even be reversed, and the main current of estuary and river run up stream for a hundred miles or more. It has been estimated that the volume of water poured into the Rio de la Plata exceeds the aggregate discharge of all the rivers of Europe put together. Nor need this be matter of surprise when the enormous extent and the character of the drainage area are taken into account. The headwaters of the Rio Blanco (a feeder of the Pilcomayo sub-system) rise only 125 miles from the coast of the Pacific, in 68 10 W. long., and those of the Rio Grande are not more than 70 miles from the coast of the Atlantic, in 44 W. long.; the basin thus extends east and west over twenty-four degrees of longitude, or 1500 miles, and the direct distance from the northmost source to the mouth of the Parana is about as great. A considerable proportion of this vast area lies Avithin the tropics, and receives an abundant rainfall, which, owing to the character of the strata, is largely carried off by the surface drainage. As an instance of the effect of this rainfall on even the secondary tributaries, Mr Bigg-Wither s experience may be cited : at Jatahy on the Tibagy he was detained from the 2d to the 25th of July by the river, after nine days of incessant downpour, rising 33 feet at a place where it was 200 yards wide, and pouring along a volume of 90,000 cubic feet per second, or twenty-five times its low-water volume (see Journ. Roy. Geogr. Soc., 1876). The three great rivers of the La Plata system are the Parana, its equal affluent the Paraguay, and the Uruguay the second being the most important as a water way, and the first the most interesting from its physical features. 1 As the general course of the Parana and the Paraguay, both of which rise in Brazil, has already been sketched in the article on that country (vol. iv. p. 222), it simply remains to direct attention to a few points of interest. In regard to the great &quot;Seven Falls&quot; of the Parana, we have still no better account than that of Azara in the 18th century; but the Hundred Cataracts or Victoria Falls of the Curityba or Y-guazu have been described in detail by the members of the first Germano- Argentine colonial land-surveying expedition to Misiones in 1883 (see Verhandl. d. Ges. f. Erdkunde zu Berlin, vol. x. pp. 357-364). For combined beauty and grandeur of scenery they claim to rank among the foremost cataracts in the world. About 6 or 7 miles higher up the river is 3 miles broad ; it gradually narrows until, after passing through a perfect labyrinth of islands (King Albert Archipelago), it pours, not in a single mass, but in numer ous streams, over a horse-shoe edge of rock into a gorge 120 to 150 feet deep. Niederlein divides the falls into three groups a northern or Brazilian, a central or insular, and a southern or Argentine, to which he has attached respectively the names of the Emperor Don Pedro, the Emperor William, and General Roca. The river continues for some distance shut in by overhanging cliffs ; and a large number of secondary cataracts (Bosetti Falls, Prince Bismarck Falls, &amp;lt;fcc.) are formed by tributary streams, and add to the bewildering beauty of the scene. The watersheds between the north-eastern headwaters of the Paraguay system and the southern affluents of the Amazons are so low and narrow that in some instances canoes have been conveyed overland from the one to the other. Interest has recently been concentrated on the exploration of the Pilcomayo, a right-hand tributary which joins the Paraguay proper in 25 20 S. lat. Though its sources have long been known, all attempts to trace it downward from Bolivia or upward from the Argentine Republic 1 The word Parana, meaning simply river, appears, it is to be re membered, alone or in composition again and again throughout South America. See Lallemant, in Zeitschr. fur Krdk., Berlin, 1863, p. 156. had been foiled by the hostility of the Indians. At length, on April 27, 1882, Dr Crevaux, the great French explorer of South- American rivers, was slain with all his party by the Tobas at a place called Ipanticapu. General interest was thus aroused ; and the task in which Dr Crevaux perished has since been practi cally accomplished by Dr Thouar, his fellow-countryman, who, leaving the San Francisco mission-station on 10th September 1883, reached the mouth of the river on 10th November, though he had not been able to keep close to its course in the lower section of the journey. The Pilcomayo rises in Vilcapujia (a mountain 13,500 feet high to the E. of Lago Poopo), and passes between the Cordillera of Livichuco and the Cordillera de los Frailes, a few miles to the north of Potosi. It cuts through the last range of the. Andes in 21 16 50&quot; S. lat. and 63 25 V. long., and enters the plains of the Gran Chaco at a height of 1456 feet above sea-level (J. 13. Mine-bin-). It is soon after joined by the Pilaga, which brings down the waters of the Rio Blanco and other streams from the mountains. Till in its south-eastern course it reaches 22 S. lat., the river has a very regular course, flowing at the rate of 6500 feet per hour over asandy bed 600 to 700 feet wide, unimpeded by rocks or trees, and enclosed by steep banks 15 to 20 feet high, above which the country stretches out in pasture-covered plains. Farther down tire banks increase in height to from 20 to 45 feet, and embrace a channel or valley 5500 feet or more in breadth, though the actual river does not exceed 150 or 200 feet. At the point called Cabello Muerto, 24 20 S. lat., commence the marshy plains of the lower course, in which the banks hardly rise above the level of the water, and a whole series of lagoons lie at a distance of a mile or two on the left hand. So flat is the country, and so tortuous the river that when Mr Robinson, in 1873, ascended for 150 miles, he never lost sight of the white houses of Asuncion. 3 About 150 miles below the mouth of the Pilcomayo the Paraguay is joined by another Andean river the Rio Vermejo or Y-pyta, whose red waters, pouring into the dark clear water of the main stream, are sufficient to tinge the whole current downwards to the conflu ence of the Parana. &quot; From the junction of its headstrenms down, to the Paraguay, the Vermejo does not receive a single aiflueiit ; its breadth varies from 70 to 250 yards, its depth from 5 to 16 feet; and the current appears to average 1J miles an hour&quot; (Keith Johnston). Its navigability was shown about 1780 by the Fran ciscan missionaries Murillo and La-pa descending the whole way in a canoe, but it was not till 1874 that, under Don Katalio Roldan, the regular navigation was undertaken. At their confluence the Paraguay has a width of half a mile, the Parana of 3 miles. The united river continues for 686 miles, first in a south-south-west, then in a south, and finally in a south-east direction before it reaches the head of the La Plata estuary. Down to Diamante, or for 433 miles, its left bank is at intervals formed by lines of bold blufl s from 100 to 200 feet high, on which several of the more important towns are built ; but the channel often breaks up so as to enclose extensive islands. The worst reach in this respect is the 45 miles below Goya, a little town in 29 7 S. lat. At Diamante begins the enormous delta (some 5000 or 6000 square miles) which is traversed by countless and changing chan nels, and presents nothing else, even if viewed from the masthead of the steamer, but a boundless labyrinth of islands clothed with exuberant vegetation. The two chief lines of navigation through this deltaic region are the Parana de las Palmas(so called by Cabot, in 1526, but now showing comparatively few palms among its- ceibos, willows, and poplars) and the Parana Guazu. The former has its mouth about 24 miles north of Buenos Ayres, the latter joining the estuary of the Uruguay 22 miles farther north, in 34 N. lat. and 58 24 30&quot; W. long. The third great confluent of the La Plata system, the Uruguay, is. quite unlike the other two. Instead of having a fairly steady and continuous flow, it appears sometimes as an insignificant torrent and at other times as a magnificent river. It has its headwaters in the Serra Gcral, and for several hundred miles continues to flow west through Brazil (forming the northern boundary of l!io Grande do Sul province), as if it meant, like the Curityba, to carry its waters to the Parana ; but about 54 W. long, it is turned aside by the mountain range of Misiones, and flows south-west and south almost parallel with the Parana. It has a total length of 950 miles, and a drainage area of 200,000 square miles. In the matter of annual rise and fall the three rivers differ con siderably. The Paraguay is regular, reaching its lowest stage in the end of February, and its highest about the end of June, and showing an average difference of level not exceeding 15 feet. The ordinary flow at Asuncion is between 97,400 and 99,950 cubic feet per second. Above the junction of the Paraguay the Parana appears to have numerous and rapid risings at irregular intervals, but to reach its maximum in December. Below the junction it has much the same movement as the Paraguay, having high water in sum- &quot; Eastern Bolivia, &c.,&quot; in Proc. Roy. Geo.Soc., 1881. 3 See Thouar s account in L Exploration, 1884 ; and map of Piloomayo, in Bui. Inst. Geogr. Argentina, 1882.