Mle (Gr. Nes; Lat. Nilus; Arab. En-Nil), the principal river of Africa, and one of the largest and most famous rivers of the world. The name is of Semitic origin, and is applied to rivers that periodically overflow and irrigate their banks. Near the city of Khar-toom, in the Egyptian province of Soudan or Sennaar, in lat, 15° 36' N., lon. 32° 38' E., two great rivers unite, the larger of which comes from the southwest, and is called in Arabic Bahr el-Abiad or AVhite river, and in English is commonly known as the White Nile. This appellation is derived from the color given to its waters by the clay with which they are saturated. The other river flows from the southeast, and is called in Arabic Bahr el-Azrek, Blue river, and in English is commonly termed the Blue Nile. It is the Asta-pus of ancient geography, and was long regarded as the true Nile. It is formed by the junction of the Abai and Dedhesa rivers, about lat. 10°30'N.; and the question which of these is the main stream of the Blue Nile, and which the tributary, has been a subject of controversy among geographers.

The weight of opinion is in favor of regarding the Dedhesa as the principal river, which if this view is correct rises in the Galla country S. of Abyssinia. On the other hand, the sources of the Abai were visited, as being those of the Nile, in the 16th century by the Portuguese missionary Paez, and in 1770 by the celebrated Scottish traveller James Bruce, who traced them to a point S. of the Tzana or Dembea lake in Abyssinia, in lat. 10°.58' N., lon. 30° 50' E., at an altitude of 6,000 ft. above the sea level. Thence the river flows about 80 m. N. W. into the lake itself on its W. side, through it, and out again on its S. E. side. Its current is so rapid that it scarcely mingles its waters with those of the lake. Flowing southward in many cataracts, it winds around the mountainous region of Gojam till by a bend to the northwest it returns to within about 70 m. of its source. While forming this remarkable curve, which makes Gojam a peninsula, the Abai receives numerous streams from the mountains of that peninsula. The total length of the Blue Nile, measured from the sources of the Abai, is supposed to be about 800 m.

The river is navigable as far as the district of Fazogle, between the 11th and 12th parallels of latitude, about 1,500 m. from the Mediterranean. - The superior magnitude of the Bahr el-Abiad unquestionably entitles it to be considered the Nile proper; and a correct determination of the sources of this river has justly been regarded as the greatest geographical problem of modern times. It has been at least approximately solved by the discovery of two great lakes lying side by side directly under the equator, and known respectively as the Victoria N'yanza and the Albert N'yanza. The first of these equatorial fresh-water basins was discovered on July 30, 1858, by Capt. J. H. Speke of the British Indian army, who in 1862 explored its western and northern margin, in company with Capt. (now Col.) J. W. Grant. According to his observations, it is 3,308 ft. above the sea level, and extends from lat. 2° 24' S. to 0° 21' N., a distance of nearly 200 m., with its westernmost shore in about Ion. 31° 30' E., although by far the largest portion of the lake lies E. of the 32d meridian. The measurements taken on his first journey, however, showed an elevation of 3,740 ft. above the ocean.

From these observations those of Baker, who visited the Victoria N'yanza in 1864, differ materially. (See N'yanza.) The width of the lake is unknown. Its outlet, the Somerset river or Victoria Nile, supposed by Speke to be the Bahr el-Abiad itself, flows northward and westward into the Albert N'yanza, in lat. 2° 16' N., on the E. shore of that lake, about 30 m. S. of its N. E. extremity. On March 14, 1864, Mr. (now Sir) Samuel Baker discovered this second great lake, the Albert N'yanza, whose outlet is the White Nile of Egypt, of which the lake had hitherto been supposed from native report to be merely an extensive but sluggish backwater. The most southerly point which he visited on its E. shore is probably not more than 100 m. N. W. of the Victoria N'yanza. The Albert N'yanza is 2,720 ft. above the ocean, according to Baker's corrected observations. The width of the northern portion is estimated at 60 m.; it narrows to 17 m. near the exit of the Nile, which is not far from lat. 2° 45' N., lon. 31° 30' E. From this point the lake extends some distance N. W., but how far is not known.

The only knowledge of its prolongation southward which we possess is derived from native accounts, which represent it as extending to between lat. 1° and 2° S., where it is said to bend W. Its shores so far as known are for the most part rocky and mountainous. The existence of these lakes confirms to some extent the notions of the geographer Claudius Ptolemy, who in the 2d century of our era stated the sources of the Nile to be in two lakes lying N. of a snowy range which he calls the mountains of the Moon, and which he describes as extending for 10° of longitude along the parallel of lat. 12° 30' S. From the snows of these mountains were principally derived the waters of the two lakes, which were due N. of the mountains, the western lake in lat. 6° and the eastern in 7° S., with a distance between them of 8° of longitude. Owing to the imperfection of astronomical science in his day, his latitudes and longitudes are incorrectly given. Notwithstanding the discovery, however, that from the Albert N'yanza comes the Nile proper, and that the Somerset river, flowing from the Victoria N'yanza into this more northern lake, must be regarded as at least an important tributary, if not the upper course of the veritable Nile, the ultimate sources of the great river still remain undetermined.

There is every indication that they lie S. of the two great equatorial lakes, and the probability that a channel exists between one of these lakes and Lake Tanganyika was long ago suggested. The altitude of Tanganyika above the level of the sea is 1,844 ft. according to Burton and Speke, 2,586 ft. according to Livingstone, and 2,711.2 ft. as measured by Lieut. L. V. Cameron of the British navy, in 1874. The largest of these results is not equal to the elevation of the Albert N'yanza, itself far below the level of the Victoria lake; so that if we assume as correct the maximum altitude obtained for Lake Tanganyika, it is still impossible that its waters should flow into the Albert N'yanza, unless Baker's measurement of the height of that lake was erroneous. Under the belief, however, that an outlet existed, forming such a communication, Livingstone, accompanied by Mr. H. M. Stanley, explored the northern end of Tanganyika in 1871. Contrary to previous supposition, the Lusize or Rusizi river, at this extremity of the lake, proved to be an affluent, and the travellers were unable to find any outflow whatever to the north; the other streams of the region also flowed into the lake, none of them out of it.

The weight of opinion among European geographers is opposed to the conclusion reached by Livingstone, that the vast lacustrine river system W. of the Tanganyika lake, which he discovered during his final sojourn in Africa, is connected with the basin of the Nile. The Lualaba, which appears to be the principal stream of this vast network, rises directly S. of Lake Tanganyika, under the name of the Chambeze, and flows thence S. W. into Lake Bangweolo or Bemba, which, according to Livingstone's uncorrected map extends 150 m. from E. to W. and 80 m. from N. to S., at a height of 3,688 ft. above the sea, between lat. 10° 55' and 12° S., and lon. 28° 15' and 30° 35' E. Emerging from the X. W. corner of this lake, with a width of four miles, as the Luapula, the river follows a circuitous course, the general direction of which is exactly N., until it falls into the Moero Oka-ta, "the great lake Moero," which is bisected by the 9th parallel of S. latitude, and lies between Ion. 28° and 29° E. Livingstone describes this lake as about 50 m. long from N. to S., with a width ranging from 12 to 40 m., and its altitude is marked on his map as 3,000 ft.

From its northern termination issues the Lualaba under that name, distinguished by him however as Webb's Lualaba, flowing northward to the 7th degree of S. latitude, which it follows toward the west from the 28th to the 26th meridian, through Lake Kamolondo, a sheet of water supposed to be not less than 150 m. long. After leaving this lake the direction of the river is again northerly, and at the lowest point in its course yet reached, just S. of the 4th degree of S. latitude, the width of the stream is 3,000 yards. Beyond this, according to native information, it pours into a reedy lake which stretches nearly up to the equator. It is apparent from what has been stated that the Lualaba occupies a valley trending northward, situated W. of the Tanganyika lake and generally parallel to it. Still further W. is the valley of the Lufira, a river which is believed to fall into Lake Kamolondo on its S. W. shore. Beyond this lies the valley of the Loeki or Lomame, another great river, which traverses a lake lying W. of Kamolondo, known to the natives as Chebungo, but named Lake Lincoln by Livingstone. It is conjectured that this river, which he called Young's Lualaba, joins the Lualaba proper, already described, at some point between Kamolondo and the equator.

The elevated plateau, from which proceeds this entire system of 200,000 sq. m. of drainage, is described by Livingstone as extending along the 12th degree of S. latitude about 700 m. E. and W., with an altitude which he estimates at 6,000 ft. A doubt whether its waters might not possibly find their way into the Congo instead of into the Nile is recorded in his last journals, under the date of June 24, 1872. The improbability that they belong to the Nile basin has been strengthened by Schwein-furth's discovery in 1870 of the westward-flowing river Welle, which he crossed in about lat. 3° 30' X., S. of the mountains among which rise the principal known tributaries of the Bahrel-Ghazal, the great western arm of the Nile. He learned that the source of the Welle was m the mountainous country W. of the Albert lake. The course of this river tends to confirm the view that the watershed of the Lualaba system is wholly western, and cannot therefore be connected with the Nile; but further explorations are necessary to a satisfactory determination of the question. - The White Nile emerges from the Albert N'yanza into a valley of green reeds, from 4 to 6 m. wide, bordered on the west by the range of mountains which bounds the W. shore of the lake.

Unbroken by a single cataract, it flows with a scarcely perceptible current, and in some places several miles in width, northerly to Afuddo, 2,116 ft. above the sea, in lat. 3° 32' N., where there is a fall of from 30 to 40 ft. A few miles further down it receives from the east its first important affluent, the Asua river, with a channel over 100 yards wide and 15 ft. deep during the rains, but without water in the dry season. The country on the west continues mountainous as far as lat. 4° N., where the Nile is about 650 ft. broad and from 5 to 8 ft. deep. At lat. 4° 37' the river descends a series of rapids to Gondokoro, about 20 m. below, a small ivory-trading station on the E. bank, celebrated as a starting point of exploration. The altitude above the ocean here is 1,559 ft. The Nile now leaves the hill region and passes into a well wooded and thickly populated country, the level of which is only about 4 ft. above the river. Beyond lat. 5° the river makes a great bend westward through nearly three degrees of longitude, returning to the meridian of Gondokoro before reaching lat. 10°. After passing lat. 6° the character of the country changes. The forests disappear, and the shores become marshy and covered with tall grass.

The course of the river is exceedingly tortuous and its current sluggish, not exceeding 3 m. an hour, while the width of clear water is about 120 yards. Two small tributaries from the west join the Nile in this part of its course, but are full only in the wet season. In lat. 9° 16' is the mouth of its greatest western affluent, the Bahr el-Ghazal. Here the waters expand into a shallow lacustrine formation known on the maps as Lake No, but more properly designated Mogren el-Bohoor, the mouth of the streams. It is described by Baker as having the appearance of a lake 3 m. long by 1 m. wide, varying according to the seasons; but it is divided into a perfect labyrinth of channels, and is so obstructed by floating vegetation as frequently to render navigation utterly impracticable. The navigable portion of the Bahr el-Ghazal, or Gazelle river, properly so called, does not extend more than 140 m. from the Nile, and terminates in an island-studded lake-like basin called the Meshera or Kyt, situated in about lat. 8° 35' N., lon. 29° 15' E. This basin presents the aspect of an extensive backwater. The eastward current is extremely languid, and indeed is frequently only perceptible in the upper course of the river, the depth of which varies from 8 to 14 ft.

Sixteen miles below the Meshera the Gazelle receives the Bahr el-Dyoor from the south, and still further down its volume is increased by the waters of the Bahr el-Arab which flows almost directly from the west. This tributary, which Schweinfurth believes to be the main stream, is said to be unfordable at a distance of 300 m. above its mouth, while the Dyoor and all the S. W. affluents of the Gazelle are known to be much smaller. The drainage area of the Bahr el-Ghazal and its tributaries is estimated by Schweinfurth at 150,000 sq. m.; there are great discrepancies, however, between the views of different explorers of the Nile, as to the importance of this western branch and the actual quantity of water which it supplies to the main stream. It is about 1,000 ft. wide at the mouth of the Bahr el-Arab. A few miles N. of its confluence with the Gazelle, the Nile receives from the south the Bahr Giraffe, a river about 70 yards wide and 19 ft. deep in the dry season, once believed to be an independent tributary stream, but now known to be an eastern offset of the Bahr el-Abiad, which it leaves in the Aliab country not far from lat. 6° N, and rejoins at this point, lat. 9° 25'. Although densely clogged with water plants, it has sometimes afforded a navigable route up the Nile for ivory merchants, when that by the main channel has been impassable by reason of the grass barrier.

The junction of the Sobat is 38 m. below, being about 750 m. from Gon-dokoro. Baker regards this as probably the most powerful affluent of the Nile. It is 650 ft. broad, and brings down a vast volume of yellow water, in a swift and strong current from 26 to 28 ft. in depth. It comes from the southeast, and is supposed to rise in the Kaffa country S. of Abyssinia. Little is known of its upper course, which has never been explored, but the earthy matter which it holds in solution indicates a mountain origin. The distance from the mouth of the Sobat to Khar-toom is 684 m. The river increases in width from 1,500 yards to 2 m., flowing between the lands of the Dinkas on the east and those of the Shillooks on the west. The marshy banks and floating islands of aquatic plants are left behind, and the Nile emerges into a perfectly level region, where arboreal vegetation is confined mainly to the margin of the river, and consists principally of mimosas. At rare intervals the monotonous character of the landscape is diversified by an isolated elevation, and the right bank of the river, through several degrees of latitude before reaching Khar-toom, is bordered by a succession of sand banks 30 ft. high.

Immense numbers of cattle are pastured on the light but rich soil of the shores, and innumerable ducks and geese haunt the stream. - From Khartoom the united waters of the White Nile and Blue Nile flow northward about 50 m., and then make a sudden bend to the east between a thick cluster of islands. At this point there is a rapid extending half way across the river, known as the sixth cataract of the Nile, it being the last which is met in ascending from the sea till the traveller reaches on the White Nile the rapids above Gondokoro, and on the Blue Nile the cataracts by which the river descends from the Abyssinian highlands. Here the Nile is very narrow, being compressed between high hills of naked red sandstone rock. From the sixth cataract it flows in a N. E. direction to Shendy, and is studded with islands covered with a luxuriant growth of palms, mimosas, acacias, sycamores, and other trees. The banks are high and steep and covered with bushes and rank grass. Reefs of black rock make the navigation intricate and dangerous. The country is thickly populated. Shendy is a long straggling town of mud huts, with about 10,000 inhabitants. Thence the river runs N. E. past the ruins of Meroe through a well cultivated region.

In lat. 17° 37', 160 m. below Khartoom, the Abyssinian river Atbara, called also Bahr el-Aswat or Black river from the quantity of black earth brought down by it during the rains, enters the Nile on the right bank, flowing from the southeast. It is the ancient Astaboras. The peninsula between it and the Blue Nile was the ancient kingdom of Meroe, which was called an island by the Greek and Roman writers, who were accustomed to give this name to the irregular spaces included between confluent rivers. The Atbara is the last affluent of the Nile, which for the rest of its course presents the unparalleled phenomenon of a river flowing 1,500 m. without a tributary. It contributes to the Nile the largest part of the slimy mud which fertilizes Egypt. The Atbara is formed about lat. 14° 15' by two great streams, the larger of which bears the name of Tacazze, and rises in the table land of Abyssinia; the other, which is considered the direct upper course of the Atbara, has its sources in the highlands N. and N. W. of Lake Tzana or Dembea. From its confluence with the Atbara the Nile flows through Nubia for 700 m. to Syene or Asswan on the frontiers of Egypt. It passes over a series of rapids and cataracts, all formed by granite or kindred rocks.

For 120 m. from the Atbara it runs nearly N. through the province of Berber. A strip of arable land about 2 m. in breadth borders the river; beyond it all is desert, the inundation not extending further. At Abu Hammed, where the river is divided by the large rocky island of Mograt, it makes a great bend S. W., and runs in that direction about 150 m., enclosing on its left bank a region called the desert of Bahiuda, which was occupied in ancient times by the Nuba), from whom Nubia derives its name. The navigation in this part is impeded by rapids, and the land susceptible of cultivation is so small in extent that the inhabitants avail themselves of the patches of loamy soil which the river deposits in the rocky hollows. Travellers going down the Nile quit the river at Abu Hammed and cross the desert to Korosko, a march of 250 m., while by the course of the river the distance between the same points is upward of 600 m. The banks of the Nile where it skirts the desert of Bahiuda on the north are without antiquities; hut at Noori on the left bank, below the fourth cataract, are the remains of 35 pyramids, of which about half arc in good preservation; they have, however, no sculptures or hieroglyphics, nor are there any ruins which indicate the former existence of a city.

Nearly opposite Noori, on the right bank, is Jebel Barkal, a hill of crumbling sandstone 400 ft. high and a mile distant from the river. On the W. side of the hill are 13 pyramids from 35 to 00 ft. high. Here are also the remains of several large Egyptian temples, one of them nearly 500 ft. long. These ruins are supposed to mark the southern limits of the empire of the Pharaohs, and the city to which they belonged was probably Napata, the capital of Tirhakah, the king of the Ethiopians, and also of those sovereigns of Ethiopia who are mentioned in the ancient history of Egypt. A short distance below Jebel Barkal, on the right bank of the river, is the village of Me-rawe, nearly opposite to which is the point from which travellers up the Nile begin their march across the desert of Bahiuda to Shendy, and thus cut off the great upper bend of the river. After passing Merawo the Nile continues S. W. till it reaches lat. 18°, when it again turns X. In this part of its course it is about half a mile wide. The desert on both sides reaches to the banks, and there is little cultivate land except on the islands. The province of Dongola begins at this point, and extends northward about 175 m.

This region is tolerably fertile, the banks of the river being no longer rocky, and the annual inundation diffusing itself over a large extent of land, abounding in fine pastures where excellent horses are bred. A little above the third cataract, in lat. 10° 24', is the island of Argo, which is 12 m. long, and contains a number of ruins, among them two overthrown colossal statues of gray granite, in Ethiopian costume with Egyptian features. Below the third cataract, near lat. 19° 45'. the Nile makes a bend to the east; and travellers descending the river usually take a straight line through the desert to Saleb on the left bank, where are found the ruins of a temple remarkable for the elegance of its architecture and its imposing and picturesque position on the line which separates the desert from the fertile land. A few miles below, the large island of Say divides the river, which soon after contracts between granite rocks so closely that it is hut a few hundred feet in width. The rocks hang over the shore and fill the river with shoals, causing so many eddies, rapids, and shallows, that navigation is practicable only at the time of highest flood, and is even then dangerous.

About half way between the island of Say and the second cataract, in lat. 21 27, is the village of Semneh on the left bank, where are the remains of a small but interesting temple of the third Thothmes. As the river approaches the second cataract, near the 22d parallel, the porphyritic and granitic rocks on its banks give place to sandstone. The second cataract, which was called by the ancients the great cataract, is, like all the others, formed by primitive rocks rising through the sandstone, in a succession of islands dividing the stream, which foams and rushes between them, with a roar which may be heard at the distance of more than a mile. It is rather a collection of rapids than a fall. A city once existed here, and the remains of three ancient temples are yet visible. From the second cataract to the frontier of Egypt, a distance of 220 m., there is a multitude of temples, some on the right, some on the left bank of the river, the most remarkable of which are those of Abu Sambul or Ipsambul, on the left bank, two days' journey below the cataract. (See Ipsambul.) A few miles lower down, at Ibrim, the ancient Premis, are ruins of the same kind, of the age of Thothmes I. and III., and Barneses II. Just beyond Ibrim the channel of the river is compressed between a range of sandstone hills rising almost perpendicularly, so close to the shore that there is hardly room to pass between their bases and the water.

A few miles below, at Derr, the capital of Lower Nubia, the river bends abruptly S. E. and then, near Korosko, again N. All this region abounds in temples of Barneses the Great, Thothmes III. and IV., and Amenophis II. Amada, two hours' sail below Derr and on the opposite bank, has a temple whose sculptures are remarkable for the brightness of their colors, having been preserved by the early Christians, who covered them with mud and mortar to conceal them from their sight; and the traveller proceeding northward passes in rapid succession Wady es-Seboo, the valley of lions or sphinxes; Dakkeh, the ancient Pselchis, the site of a temple of Ergamenes, mentioned by Dio-dorus as resisting the tyranny of the priests (the deity of which was Hermes Trismegistus, identified with Thoth), the furthest S. point at which any traces of Greek or Roman dominion have been found on monuments; Dendoor, the site of a temple of the age of Augustus; and Kalabshe, the ancient Talmis, situated in lat. 23° 30', directly under the tropic of Cancer, where is the largest temple in Nubia, which was built in the reign of Augustus, and enlarged by Caligula, Trajan, and Severus. In this part of its course the river flows between mountains on each side rising from the water's edge, and piles of dark sandstone or porphyry rock, sometimes 1,000 ft. in height, where a blade of grass never grew, every notch and jag on their crests, every fissure on their sides, revealed in a pure and crystalline atmosphere.

Their hue near at hand is a glaring brown; in the distance an intense violet. On the W. bank they are lower; and the sand of that vast desert, which stretches unbroken to the Atlantic, has heaped itself over their shoulders and poured long drifts and rills even to the water. The arable land is a mere hem, a few yards in breadth, on each bank of the river, supporting a few scattering date palms, which are the principal dependence of the Nubians. The rise of the Nile during the annual inundation is in some parts of this region as much as 30 ft., but the height of the banks is such that the adjacent land derives but little benefit from the overflow. When the river is low the fields are irrigated by water wheels of clumsy construction. At the boundary between Nubia and Egypt is the island of Philae, where the Nile is 3,000 ft. broad. The island is about a quarter of a mile long, and is covered with picturesque ruins of temples, almost entirely of the times of the Ptolemies and of the Roman emperors. Immediately below Philaee is the first cataract, the last in descending the river, which extends to Asswan, and to the island of Elephantine. The ridge of granite by which they are formed crosses the river and extends into the desert on either side.

The rocks are much more rugged than those of the second cataract, and rise to the height of 40 ft. There are three principal falls; at the steepest, which is about 30 ft. wide, the descent is about 12 ft. in 100. The entire descent in a space of 5 m. is 80 ft., and the whole constitutes a series of rapids rather than falls, the highest single fall not exceeding 6 ft. The channel has been widened, and may be passed by boats at all seasons. From the quarries on the banks were derived the colossal statues, obelisks, and monoliths which are found throughout Egypt. The island of Elephantine, in lat. 24° 5', just opposite Syene, is fertile and covered with verdure. From Asswan to the Mediterranean, a distance of 700 m., the Nile runs down a gentle declivity of about 300 ft. The valley through which it flows till it reaches the apex of the delta varies in breadth, with an average of 7 m., the greatest width being 11 m. A short distance below Asswan begins a district of sandstone, which extends nearly to lat. 25°. This part of the valley is narrow and barren.

Near lat. 25° is Edfoo, the ancient Apollinopolis Magna, which stands on the left bank, and contains two famous temples built by the Ptolemies, the largest of which is the best preserved of all the edifices of the kind in Egypt. At Esne, the ancient Latopolis, on the left bank, 30 m. N. W., the valley of the river expands to the width of nearly 5 m. Here are the remains of a magnificent temple built by the Roman emperors. Still lower down the rocks of Je-belain or the "two mountains" approach so near each other on opposite sides, that the river occupies nearly the whole valley. Here the sandstone disappears, and is succeeded by limestone hills, which border the river till it reaches the delta. There is from this point a wider interval of fertile land, especially on the W. side. Fifty miles below Edfoo, in lat. 25° 38', stand the magnificent ruins of Thebes, the ancient capital of Upper Egypt. Here the river is 1¼ m. wide, and is divided by islands. On the right bank are the modern villages of Luxor and Karnak, on the left Medinet Abu and Goorna. From Thebes the traveller descending the river passes numerous ruins, at Medamot, at Koos or Apollinopolis Parva, and at Coptos on the right bank; and on the left bank, 38 m. below Thebes, reaches Denderah, the ancient Tentyra, where are seen the majestic remains of the temple dedicated to Athor or Aphrodite, or, as some believe, to Isis, one of the most impressive of Egyptian monuments.

Not far below this the river bends W., and at How or Diospolis Parva on the left bank begins the canal or ancient branch of the Nile, called the Bahr Yusuf or river of Joseph, which flows between the river and the Libyan hills to the entrance of the Fayoom. Not far distant is Abydos or This, one of the most ancient cities of Egypt, the birthplace of Menes, the first of the Pharaohs. Beyond this are Chemmis or Panopolis on the E. bank; Si-oot, the ancient Lycopolis, on the W. bank; and a little lower down, on both banks, the grottoes of Manfaloot, the sepulchres of embalmed dogs, cats, and crocodiles. Still lower are the ruins of Hermopolis Magna on the W. side, and on the E. side the remains of Antinoė, built by Hadrian in the Roman style. North of Antinoe, on the E. bank, are the famous grottoes of Beni-Hassan, about 30 in number, excavated by the kings of the 12th dynasty, containing paintings of scenes in the civil and domestic life of the ancient Egyptians, from which modern Egyptologists have derived most of the existing knowledge of the manners and customs of that people.

From this point the course of the river presents no remarkable feature till it reaches Beni-Sooef in lat. 29° 9', where the Libyan chain of hills begins to retire from the river, bends N. W., and again returning toward the river encloses the province of Fayoom, in which were the lake of Mceris, the labyrinth, and the city of Crocodi-lopolis. The next objects of interest in descending the stream are the pyramids of Da-shoor and Sakkara, and finally the great pyramids of Gizeh, the royal sepulchres of ancient Memphis. The site of this ancient city is marked by the mounds of Mitrahenny. A few miles lower down, on the E. bank, is Boolak, the port of Cairo, which was originally on an island. A little above Cairo the double chain of hills between which the Nile has so long flowed terminates, those on the E. side turning off toward the head of the Red sea, and those on the opposite side returning toward the northwest. From this point the Nile expands, and its current slackens, and soon begins to flow sluggishly in separate branches, though at Rosetta, only 6 m. from the sea, the water is perfectly fresh except after long prevalence of northerly winds. Twelve miles below Cairo is the apex of the delta, the point of separation, which in ancient times was 6 or 7 m. higher up.

Thence the delta extends 90 m. seaward, a broad and perfectly level alluvial plain, without a hill, rock, or natural elevation of any kind. Anciently the Nile traversed the delta by seven branches, of which only three appear to have been of much size, the Pelusiao or eastern arm, the Canopic or western, and the Sebennytic or middle. The river now enters the Mediterranean by two outlets, the Rosetta branch on the west and the Damietta branch on the east, with their mouths in lat. 31° 36' N., separated from each other by 95 m. of seacoast. The Pelusiac branch is now dry. On the E. side of it, not far from the apex of the delta, was lleliopolis, the On of Scripture, of whose ruins only an obelisk remains. Forty miles lower down was Bubastis; and still lower, near the sea, though its remains are now several miles inland, was Pelusium, from which the arm derived its name. The ancient Sebennytie branch had its mouth where the lake of Boorlos now lies. It has been partially renewed in a free wide canal, which starts midway between the two modern branches, and continues as far as Tanta, about half way between Cairo and the sea.

The Canopic branch is represented by the first part of the present Rosetta branch as far as lat. 31°, whence it turned to the west and entered the sea near the bay of Aboukir. The W. or Rosetta branch is the usual channel of communication between Alexandria and Cairo, and is navigated by small steamers at regular intervals; it is 1,800 ft. broad, and has in the dry season a depth of about 5 ft. The Damietta branch is 900 ft. wide, and its depth when the river is lowest is about 8 ft. - In the ordinary state of its waters the Nile has not depth sufficient for vessels of more than 60 tons burden, but during the height of the inundation the depth of water is 40 ft., and large vessels can ascend to Cairo. The river begins to rise as early as April in its upper branches, but not until the latter part of June in Egypt, where it reaches its greatest height between Sept. 20 and 30, when it is usually at Cairo 24 ft. above the low-water level, and at Thebes 36 ft. About the middle of October it begins to fall, and in Egypt is at the lowest about the middle of May. The rise sometimes reaches 30 ft., and the overflow then does great damage; on the other hand, when it falls short of 18 ft., the harvests fail, and Egypt experiences a famine.

Of the 66 inundations between 1735 and 1801, 11 were very high, 30 good, 16 feeble, and 9 insufficient. The water of the river is charged with mud, which it deposits over the cultivated land of Egypt to an average depth of not more than the 20th part of an inch each year. Notwithstanding its turbidness, the water is sweet and wholesome, and is freely drunk by the people, among whom the saving is proverbial that In- who has drunk of theNile will always long to return and drink of it again. - On the island of Rhoddah, near Cairo, is the celebrated nilome-ter lor indicating the height of the Nile during tie- annual inundation. It consists of a square well or chamber, in the centre of which is a graduated pillar, divided into cubits of about 22 in. each. A nilometer existed at Memphis in the times of the Pharaohs, and during the reigns of the Ptolemies there was one at Hi-thyia, and another at Elephantine in the reigns of the early Roman emperors. That at Rhod-dah is attributed to the caliph Amin, who reigned from 809 to 833. During the inundation four criers proclaim every morning in the streets of Cairo the height to which the water has risen. When it has reached 18 cubits the canals are opened and it is allowed to flow over the land.

In 1847 the French engineer Linant commenced the construction of a barrage or great dam, just below the apex of the delta, whereby it was intended so to regulate the flow of water as to produce two inundations in a year; but after 62 beautiful arches had been thrown across the Rosetta branch, the work was abandoned in consequence of the practical difficulties which were encountered. - As the extent of the Nile basin is not definitely known, no accurate estimate of its area can be given; but it may safely be stated as at least 500,000 sq. m. Its approximate length, throughout all its windings, from the limit of steam navigation above Gondokoro, in lat. 4° 37' N., is 3,000 m., which gives an average descent in the river of 9 in. per mile. The average fall per mile from Ass wan to Cairo, 555 m., is 6.4 in. The additional length of the river between the point we have mentioned and its exit from the Albert N'yanza can scarcely be less than 200 m. According to Lyell, not only the fertility of the alluvial plain above Cairo, but the very existence of the delta below that capital, are due to the power possessed by the Nile of transporting mud from the interior of Africa and depositing it on its inundated plains.

The following is the composition of the Nile mud, which is generally found unstratified: silica, 42.50; alumina, 24.25; carbonate of lime, 3.85; peroxide of iron, 13.65; magnesia, 1.05; carbonate of magnesia, 1.20; humic acid, 2.80; water, 10.70. The investigations, conducted under the auspices of the royal society of England, for the purpose of ascertaining the rate of accumulation, indicate a mean increase of 3½ in. in a century; but this result requires verification, especially as there are geological reasons for believing that a slow subsidence of the land in Egypt has taken place within the historic period. - The ibis, the hippopotamus, and the crocodile are characteristic animals of the Nile fauna, all frequenting the upper portion of the river, though formerly common in the northern latitudes. The lotus and the papyrus are equally distinctive representatives of the flora. The Nile abounds with fish, among which are large eels, white trout, and a large species of salmon. - The course of the White Nile above its junction with the Blue Nile at Khartoom was first explored in 1827 by M. Linant, who ascended the stream as far as El-Ais in lat. 13° 23' N. A few years afterward Mehemet Ali, pasha of Egypt, determined to have the river explored to its sources.

Accordingly, between 1839 and 1842 three expeditions were fitted out for that purpose; the first ascended to hit. 6° 30' N., discovering on its passage the mouth of the Sobat, Lake No, and the Bahr el-Ghazal; the second reached lat. 4° 42' N.; and the third went not quite so far. In November, 1849, Dr. Knoblecher, a Roman Catholic missionary at Khartoom, accompanied the annual trading expedition sent up the Nile by the Egyptian authorities, and ascended the river to lat. 4° 10' N., then further than any other explorer had ever gone. The Bahr el-Ghazal was explored by Petherick in 1853 and the five following years, and subsequently in 1862 and 1863. In the latter year, Miss Tinné, the Dutch traveller, visited the southwestern affluents of the river, and lost her life in this region in 1869. She was succeeded in the same field, in 1869 - '71, by Schweinfurth, whose acquirements as a botanist have given exceptional value to his work. The explorations of Speke and Grant, Baker, and Livingstone have already been mentioned.

A short time prior to the first journey of Baker, however, Miani, the Italian traveller, advanced the limit of exploration from the north to a point considerably beyond Gondokoro, in the neighborhood of Afuddo, lat. 3° 32' N. Our knowledge of the White Nile has been largely increased by the recent military expedition sent out by the khe-dive for the suppression of the slave trade (1871 - '3) under the command of Sir Samuel Baker. - The following are the more important works of recent date relating to the exploration of the Nile: Petherick's "Travels in Central Africa" (1859); Speke's "Journal of the Discovery of the Source of the Nile" (1863); Baker's "Albert N'yanza" (1866), "The Nile Tributaries of Abvssinia" (1867), and " Is-maiilia "(1874); Schweinfurth's " The Heart of Africa" (2 vols., 1874); and "The Last Journals of David Livingstone" (2 vols., 1874).