SIEBRA LEONE. 147 SIEBBA NEVADA. debt had reached by 1902 the sum of $2,228,828. The popuhition of the colonj- pi-oper, in 1901, was 76,655, of whom 444 were white, and 33,518 lib- erated Africans and tlieir descendants. The Christians numbered 43,045, the pagans 24,099, the Mohammedans 9504. The popuUation of the protectorate is estimated at 1,000,000. The coast of Sierra Leone was discovered by the Portuguese in the fifteenth century and set- tled by the English in the seventeenth century, but soon abandoned. In 1787 a colony of fugi- tive slaves was sent there by English pliilanthro- pists, who had purchased some territory from the natives. The first attempt having proved unsuccessful, a second settlement was established in 1791. and in 1792 the colony was augmented by 1200 fugitive slaves from Canada and the Bahamas. In 1807 the company transferred its territory to the Crown and in 1896 a British protectorate was declared over the hinterland. Consult: Jackson. The Setflemciit of Sierra Leone (London. 1884) : Banbury, Sierra Leone (ib., 1888) ; Ingham, Sierra Leone After a Hun- dred Years (ib., 1894) : Piei'son. Seven Tears in Sierra Leone ( ib., 1897) ; Crooks. .1 Short Eis- tory of Sierra Leone (Dublin, 1901). SIEKRA MADRE, mil'dra. A name borne in common by the two chief moimtain ranges of Mexico, which are nearly parallel to either coast and inclose the great central plateau of Anahuac (q.v. ). The western range is often distinguished as the Sierra iladre Occidental or Sierra Madre del Paclfico. while the eastern range is called the Sierra JIadre Oriental. They are widely sepa- rated in the north, but gradually converge to- ward the south. A little to the south of Mexico City the intervening plateau is bridged over by the range of lofty volcanoes known as the Cordil- lera de Anahuac, and farther south the two ranges merge in the mountains of Oaxaca. The western or Pacific range is more continuous than the eastern, and also considerably higher and more nigged in its scenery. Its average height is over 8000 feet, with some peaks rising above 10,- 000 feet, and its sides are cut by deep and nar- row caiions with numerous precipitous crags. The lower slopes are covered with grass; higher up are forests of oak. while pine forests cover the high ridges. Both ranges consist of Archaean crystalline rocks, lai'gely granite, with intrusions of basaltic and other volcanic rocks. The sys- tem does not seem to be connected with the South American Andes, and its structural con- nection with the Rocky Mountains of the north has not been clearly shown. SIERRA MADRE. A mountain range ex- tending along the eastern coast of Luzon (q.v.). SIERRA MORENA, mora'na. A mountain range of Spain running along the southern edge of the great central plateau, and forming the boundary betAveen the provinces of Ciudad Real on the north and Jaen and Cordova on the south (Map: Spain, D 3). It rises but slightly above the plateau, its average elevation being about 3500 feet, but on the south it falls in a steep and imposing escarpment toward the low valley of the Guadalquivir. The railroad from Madrid to Cordova crosses it through several tun- nels in the romantic pass called the Puerto de Despeiiaperros. SIERRA NEVADA, na-va'oA (Snowy Range). A mountain range of Southern Spain, extending from the centre of the Province of (irnnada about GO miles eastward into the Prov- ince of Almeria, its crest being about 28 miles from the Mediterranean coast (Map: Spain. D 4). It forms a part of the mountain systetn sepa- rating the valley of the Guadalipiivir from the southern coast, and is the highest elevation of the Iberian Peninsula. Its greatest height is near the western end, where the peak of Mulahac^n has an altitude of 11,420 feet, and that of Veleta 11,385 feet. Eastward it merges gradually into a lower plateau region. It sends out numerous spurs inclosing deep valleys, and on the north falls in wild and rocky precipices toward the .Jenil River, on whose banks lies the city of Granada. The range consists mainly of mica slate, and though the low valleys are cov- ered with a rich vegetation, the bulk of the moun- tain consists of naked rocks. It is covered with snow a great part of the year, and- on the Veleta there are permanent glaciers, the southernmost of Europe. SIERRA NEVADA, ne-vii'dii. A mountain range in eastern California, forming the divide be- tween the Great American Basin and the valley of the Sacramento and San Joaquin rivers (Map: California, D 3). It is a tilted plateau 80 miles wide and extending in a north-northwest direction, 400 or 500 miles according as the range is consid- ered to end at Lassen Peak or at the northern State boundary. In the south it turns westward and merges with the Coast Range, and in the north it is continued into Oregon as the Cascade Moun- tains. It consists of a granitic core exposed in the higher portions, flanked by metamorphic slates, and in the lower western slopes by later marine deposits ranging from Carboniferous to Cretaceous. North of Lassen Peak, in the north- ern part of the State, these formations disappear under the great Oregon lava flow, so that here the Cascade Mountains may be said to begin, al- though the name Sierra Nevada is often extended up to the State boundary so as to include Mount Shasta. The average elevation of the crest is 10,000 feet in the southern half and somewhat less in the north. The range falls abruptly on the east to the valley floor of the Great Basin, 5000 feet below, while on the west it has a wider and more gradual slope. The Sierra Nevada, whose greatest elevation but slightly exceeds that of the Rock}' Moimtains. appears much more massive and impressive than the latter range, as it rises from a much lower level. The num- ber of peaks, howevei', is not as great as in Colorado, though there are at least 14 peaks over 12,000 feet high. The highest peaks are clustered near the southern end, and here Mount Whitney, the highest point in the United States proper, attains an altitude of 14.898 feet. Otlier high points are Fisherman Peak, 14,448 feet; Jlount Corcoran, 14,093 feet;
- Mount Kaweah, 14.000 feet; Mount Brewer, 13,-
886 feet ; Jlount Lyell, in the Yosemite Park, 13,042 feet; and iii the extreme north Mount Shasta, with an altitude of 14,380 feet. The higher portions of the range are covered with perpetual snow, and the northern slopes of some of the peaks are occupied by glaciers. The snowfall is heavy on the western slope, and feeds a large number of streams flowing to the Sacramento and San .Joaquin Rivers. Th.^se streams have cut up the slope into deep valleys, some of which, notably
