Page:Africa by Élisée Reclus, Volume 3.djvu/515

 TANGANYIKA. 423 flooding caused by the back flow of waters obstructed lower down, it is a natural lacustrine basin, with deep water almost everywhere close inshore. At a distance of 2,000 yards off Cape Kabogo, Stanley failed to reach the bottom with a 200- fathom line, and near the same point Livingstone was equally unsuccessful with one 300 fathoms long, while Giraud recorded a depth of 350 fathoms off the Karema coast. According to the reports of the Ujiji Arabs, the lake boiled up in 1862, emitting vapours and strewing the beach with debris resembling bitumen, some fragments of which were afterwards collected by Ilore. Tanganyika, that is, "Union of Waters," is fed by many afllucnts, mostly however of small size. The largest is the Malagarazi, which during the floods is no less than 1,700 yards wide at its mouth, and even in the dry season is nowhere fordable. Its farthest headstream rises in a lakelet within 330 miles of the east coast, being the point where the Congo basin approaches nearest to the Indian Ocean. The Ru-Sizi influent from the north follows exactly the main axis of the lake, which was at first supposed to send its overflow through this channel to the Nile. Storms are rare on Tanganyika, although it sometimes happens that the east winds, suddenly interrupting the normal currents from the west, sweep down the eastern slopes and violently agitate the placid surface of the lake. . These sudden squalls are mostly to be feared during the rainy season, although the swell is generally heaviest in dry weather. The angry waters are much dreaded by the native boatmen, who, when rounding the headlands, never fail to pour out libations and make other offerings to the "noble devils" inhabiting them. Those who forget to present a black sheep and a white chicken to the demon of Mount Kabogo never return, a fierce gust from the mountain swooping down and engulfing' them. The scenery, at once grand and picturesque, is pleasantly varied by Cape Kabogo on the east side, and the numerous other headlands breaking the line of verdant slopes, red sandstone cliffs, white limestone walls, granite domes and towers. The transparent waters abound in fish, such as the singa, a great resource of the riverain populations, but the shell- fish fauna is specially remark- able, more than half the species occurring nowhere else. Some of the forms are essentially marine, being apparently allied to the fossil species of the Upper Chalk in Europe and North America. The water of Tanganyika is perfectly fresh, a fact which alone made it highly probable that there must be an outflow. But when the Ru-Sizi was shown to be an affluent, and no emissary could be found at either extremity flowing in a line with the main axis, as is the case with nearly all lakes, it was at first supposed that the inflow was carried off by evaporation. Eut it was soon discovered that the level was gradually rising, flooding old beaches and forests, and submerging rocks standing over 10 feet above the old level. This phenomenon seemed to indicate that there was no issue, until the observations of Cameron, Here, and Thomson made it evident that the Lu-Kuga was certainly an intermittent emis- sary, convejdng the overflow from the west coast to ihe Congo. After reaching the level of this river, which at the outlet is over 2 miles wide, but often choked