Page:Encyclopædia Britannica, Ninth Edition, v. 20.djvu/548

Rh RHONE Fort de 1'F.cluse. About 5 J miles farther down occurs the famous Perte du Rhone, a "partially subterranean passage, now considerably modified by blasting. " The rocks forming the funnel come so close at one place that there is only a distance of about two feet from bank to bank, and a man of moderate height could stand with one foot on the French side and the other on the Savoy side and sec between the beautiful river trembling as it were with rage and hastening to escape from the defile through which it is doomed to pass. A little way farther down the river has hollowed out a passage about 30 feet wide, which retains this width for a depth of from 30 to 35 feet, when it con- tracts considerably. At this depth a stratum of harder rock has resisted the action of the water, which, however, has scooped out beneath it almost as much as above it. Along each side of the ravine the harder rock projects for eight or ten feet like a cornice. At first the water is seen through the opening down the middle ; but farther on great masses of rock from the walls of the ravine have fallen down, and, resting on the double cornice, conceal the river for a distance of some 60 paces." 1 During the summer floods the water filled the ravine far above the level of the fallen blocks, and the Perte du Rh6ne was no longer visible. 2 The rocks through which the " perte " is cut belong to the Urgonian sub- division of the Cretaceous system, the stratum which has been hollowed out being described as calcaire gris. Just below the ravine the Rhone is joined by the Valserine, which a little above Bellegarde passes through a " perte " of a similar character. Since 1871 the motive power of the main river has been utilized for the industries of Belle- garde ; a large tunnel 20 feet high and more than half a kilometre long brings the water from the south side of the perte to turbine wheels placed in the bed of the Valserine, and wire ropes transmit the power to the Bellegarde workshops on the plateau 400 feet above. 3 Below Belle- garde the river is deflected southwards by the western chain of the Jura. It receives from the left the Usses, the Fiar (which drains the lake of Annecy), and the emissary of the Lake of Bourget, the largest of the purely French lakes, and then at the junction of the Guiers (from the Grande Chartreuse) it turns north-west round the southern end of the Jura. The Ain (118 miles long), which joins it from the right, is navigable in the direction of the current, and in its upper waters has a " perte " of some interest. Farther down the main river meanders for a time with shifting channels in a bed about two miles broad, but it gathers into a single stream before its junction with the Saone. This important confluent (the ancient Arar, which according to Caesar flows " incredibili lenitate ") has its source at Viomenil in the Vosges 1300 feet above the sea, and has been joined by the Doubs, which, rising in the district between the Jura and the Vosges, is famous for the beauty of its upper gorges and for the waterfall (70 feet) known as the Saut du Doubs. 4 Southwards from Lyons, where it is 530 feet above the sea, the united river continues to be still the "arrowy Rhone"; in the 61 miles from the Saone mouth to the Ise>e it falls 180 feet, in the 18 from the Isere to the Drome 56 feet, in the 38 from the Drome to the Ardeche 164, and in the 34 from the Ardeche to the Durance 88. Those affluents, all except the last from the Savoy and Maritime Alps, are in general of little importance, but at times become formidable torrents. The same is true of the much shorter streams which bring down the waters from the eastern slopes of the Cevennes. During the inundation of the 10th September 1857, which has been frequently exceeded, the three streams the Doux, 1 De Saussure, Voyage dans les Alpes (1780-1796), ii. 90 sq. a See the elaborate papers, with maps and sections, by Renevier in Mtm. de la Soc. HeMtique, 1855 (" Mem. Geol. sur la Perte du Rhone et sea environs"), and in Bull, de la Soc. Qeologique, 1874-5, 3d ser. vol. iii. 3 See Reclus, Nouv. Qeogr. Univ., "La France," p. 215. 4 See "La Saut du Doubs," in Tour du Monde, 1880. the firieux, and the Ardeche poured into the Rhone 49,000 cubic feet per second. At Fourques d'Arles, 25 miles from the sea, the river begins to form its delta, breaking up into two main branches, the Grand Rhone passing from Aries south-east towards the Gulf of Fos, and the Petit Rhone south-west towards the Little Cam- argue. With all its rapidity of current and mass of waters it is not able to keep a clear passage to the sea through its own alluvium, which, according to M. Reclus's estimate, has since the Gallo-Roman period added from 75 to 100 square miles to the area of its delta. From the time that Alarms caused his soldiers to excavate the Fossae Marianse which have left the name of Fos to the bay already mentioned the endeavour to maintain a navigable channel inland from the sea has perplexed successive generations. Vauban himself declared " Les embouchures du Rh6ne sont incorrigibles. " The method of contracting and embanking a principal channel right out to sea failed, either because the embankments were not carried out far enough, or more probably because the tides of the Mediterranean are not sufficiently strong to aid in removing the alluvium. A canal constructed in 1802-1832 from Aries to Bouc (on the east side of the Gulf of Fos) proved too shallow for the new steam traffic. At length in 1863 a scheme brought forward by Hippolyte Pent in 1846 was adopted for the making of a canal, 11,480 feet long, 210 feet wide and 19 feet deep at low tide, from Tour St Louis on the left bank of the Grand Rhone to the Anse de Repos in the Gulf of Fos. The canal was completed in 1871, and the quays of the port of St Louis by the close of 1878, at a cost of 26,000,000 francs. Hostile critics main- tain that it will be possible to keep this channel open at the seaward end only by continual and costly dredging, but hitherto their fears seem exaggerated. The new port has been very success- ful, 1261 vessels (313,745 tons) entering in 1881 and 23i7 vessels (448,757 tons) in 1882. The regulation of the river itself is still a problem. The rapidity of the current from Lyons downwards, the extremely shifting character of the channel, and the varia- tions that take place in the volume of water are the great obstacles to be overcome. Two months of the year are lost for navigation through floods or lack of water or fogs or ice. At present (1885) a scheme combining the two systems of regularization and canaliza- tion is being carried out for the purpose of securing everywhere at low water a depth of 5 feet 3 inches. In the beginning of the present century even passenger boats used to be hauled up the river by towing ropes, and when steam was introduced it was found that the vessels had to be specially constructed to make head against the current. The laying of a continuous chain all the way from Lyons to Aries is impracticable through the shifting character of the bed ; but several methods have been adopted to overcome the difficulties of the ascent. Thus some boats advance by means of long jointed levers which catch into the ground. Or a steel wire cable with one of its ends fixed at a given spot is unwound as a steam tug descends the stream and then the tug with its convoy of boats makes its way up again by simply winding in. Or two tugs are employed, the first going in advance of the other so far that the cable which it pays out takes a sufficient hold of the bottom to enable the second to haul by it. Or, lastly, Dupuy de Lome's system is adopted, by which the boat grips the river bottom by means of two continuous chains perpetually sunk in front and emerging behind. The SaSne is much more easily dealt with than the Rhone. It is navigable as far up as Port-sur-Sa6ne, and a system of movable dams and sluices has been established to secure a depth of 6 to 7 feet at low water. The basin of the Rhone communicates with the Loire by the Canal du Centre (joining the SaSne at Chalons), with the Seine by the Burgundy Canal (joining the Saone at St Jean de Losne), with the Rhine by a canal (1783-1834) which passes from the Saone at Saint Symphorien to the Doubs, and finally ends at Strasburg, and with the Meuse and the Belgian system by a canal (Canal de 1'Est) constructed since 1875 from the Saone to the Moselle. See Boisscl, Voy. pitt. et navigation executee *; unepartie du Rhdne reptite'e non-navigable, 1795, and works on the river by Hippolyte Pent (184C), Snrell (1847), Desjardins (1866), Adrian German (1872), and De la Rochette. Also Lentheric, Let villes morles du Oolfe de Lyon, 1875, and a paper in Rev. tics Deux tfoncles,18$0; Blerzy, Torrent t,fleuve,et canauxde la France, 1878. (H. A. W.) RHONE, a department of south-eastern France, deriv- ing its name from the great river on which Lyons, its chief town, is situated, was formed in 1793 from the eastern por- tion of the department Rh6ne-et-Loire, comprising parts of Lyonnais and Beaujolais. It is bounded on the N. by Saone-et-Loire, on the E. by Ain and by Isere, on the S. and W. by Loire, and lies between 45 27' and 46 18' N. lat. and 4 15' and 4 53' E. long. The Saone and the Rhone, each for a distance of 26 miles, form its natural