Page:The New International Encyclopædia 1st ed. v. 17.djvu/466

SAGUNTUM. 426 SAHABA. foundation to Greeks from Zacynthus and Rutu- lians from Ardea. In reality there seems no rea- son to doubt that it was an Iberian city, with an admixture of Greek culture due to its conuiieree. It owes its historical importance to its connec- tion with the outbreak of the Second Punic War. ?"he town had been received into alliance by the Komans, apparently after the treaty of B.C. 226, which bound the Carthaginians not to cross the Ebro. Hannibal, who saw that war must come, attacked the city, which had refused to acknowl- edge the Carthaginian supremacy, in B.C. 219. After a desperate defense for eight months, the skill of the Carthaginian general prevailed. The R(mians thereupon demanded the surrender of Hannibal for attacking their ally, and, upon the refusal of the Carthaginians, declared war. The ruined town was subsequently rebuilt by Scipio Africanus, and appears as a municipium under Augustvis. The ancient walls (muri veteres) gave rise to the name of the modern town^ Murviedro (q.v.). SAHABA, sa-ha'ra (Ar. sahira, desert). The. The largest continuous desert on the earth's sur- face. Extending east and west between the Atlantic Ocean and the Red Sea, and north and south be- tween the Sudan and the Mediterranean coun- tries, whose southern borders overlap it, the desert embraces an area of 3,510,000 square miles, being nearlj' as large as the European mainland (Map: Africa, E 2). In the last quarter of the nineteenth century it was pro- posed to convert the western Sahara into an inland sea by admitting the waters of the Atlantic through a canal south of Morocco. It is now known that the mean elevation of this part of the desert is at least 1000 feet above the sea, that the lowest part of the region it was ex- pected to submerge is 500 feet above the sea, and that the area below sea level is comparatively insignificant. The recent discovery of fossils and limestone deposits of Cretaceous and Tertiary times extending over a wide area of the south- western part of the Sahara has led Professor de Lapparent to the conclusion that the Tertiary sea must have extended inland at least as far east as Lake Chad. He mentions other facts also that point to an unbroken sea communication be- tween India and the central Sahara by way of Egypt in Cretaceous and Tertiary times. The surface of the Sahara is not, as was once supposed, merely a monotonous and compara- tively level waste of sand. Its surface presents, on the contrary, considerable variety of aspect which makes it possible to divide it into five natural groups: (I) The western Sahara, (2) the mountain lands of the central Sahara, (3) the Libyan waste, (4) the Nile lands, and (5) the mountain zone east of the Nile. As a whole, the Sahara is a tableland whose surface has an average elevation of 1300 to 1600 feet above the sea, with only limited areas falling to 500 or 600 feet, and a few small depressions below the sea level. The most northern of the depressions beneath the sea level are the salt lakes or marshes (shotts) in the southern part of Tunis. They contain scarcely any water and are 50 to 90 feet below the level of the Mediterranean. This is now a region of date palms nourished by the springs which gush from the neighboring hills. In the eastern part of the Libyan desert is a series of deeply depressed oases sharply defined by the precipitous walls of the plateau: Aradj, 230; Siva, 98: Sittra, 82; Uttiah, 66; and the Birket el Kerun, in the Egyptian Fayum, near the Nile, 131 feet below sea level. These are the only depressions, except one, beneath sea level in Africa. A strip of considerable breadth extend- inij along the Atlantic fringe of the western Sahara from the Senegal River to Morocco may be classified as lowland (not more than 650 feet in elevation). Another strip of lowland stretches from the shotts of Tunis to the Nile. The chief distinction between the western Sa- hara and the Libyan desert is that the larger part of the western Sahara is steppes while the Libyan desert, excepting its depressed oases, is almost purely a sand waste. The two regions are separated by the great highlands of the central Sahara. About two-thirds of the westeni Sahara is composed of sterile, rock-strewn plains, and the remainder is sand waste, the plains or steppes extending across the desert from north- east to southwest, the sand desert being inter- spersed among them. There are many deep val- leys, the beds of streams flowing from the Atlas ranges or from the western slopes of the high- lands of 'the central Sahara, some of the northern wadais or rivers carrying at times considerable water a short distance into the desert; but the water in most of the basins sinks through the permeable strata to an impermeable one of clay, forming vast subterranean reservoirs need- ing only to be tapped to spread life and wealth over the surrounding surface. The oases are situ- ated above these underground supplies and may be extended wherever water can be brought to the surface. The most remarkable of these tracts is El Erg, whose wells are capable of irrigating as many as 8,000,000 date palms. The oases em- brace only about 80,000 square miles, or only a little more than one-fortieth of the desert area. The lines of wells that make a number of caravan routes across the western Sahara possible are found along the courses of these subterranean water supplies. The valleys show that at an earlier period the climatic conditions permitted far larger volujiies of water to flow on the sur- face; and evaporation has produced numerous salt pans, particularly in the west and south. The plateau of the central Sahara, which ex- tends three-fourths of the way across the desert from northwest to southeast, is from 1900 to 2500 feet in elevation, and above it rise moun- tain ranges (Ahaggar, Tibesti, and Air), some of the peaks being 6000 to 9800 feet high, and snow-crowned in winter. The Ahaggar mountain land is the source of several long, wide river valleys, now waterless above ground, but con- tributing their subterranean supplies for the creation of a series of wells. East of the mountains to the Nile extends the Libyan waste, waterless, barren, almost devoid of life save for its few inhabited oases, its sand dunes, often piled up by the winds to a height of 300 or 400 feet, stretch- ing away to the Nile. This sand waste, remark- ably difficult to cross, has been characterized by Rohlfs as the most treacherous and tediously monotonous region of the Sahara. The Nile lands and the eastern mountains are described in the articles Egypt and Nile. The Sahara is dry in winter because it is then an area of high pressure, forcing the air currents