Online Encyclopedia

Search over 40,000 articles from the original, classic Encyclopedia Britannica, 11th Edition.

NILE

Online Encyclopedia
Originally appearing in Volume V19, Page 699 of the 1911 Encyclopedia Britannica.
Spread the word: del.icio.us del.icio.us it!

NILE  , the longest See also:

river of See also:Africa, and second in length of all the See also:rivers of the globe, draining a vast See also:area in See also:north-See also:east Africa, from the East See also:African See also:lake See also:plateau to the shores of the Mediterranean . Although falling See also:short of the length of the See also:Mississippi See also:Missouri (4194 M. according to the estimate of See also:General Tillo'), the Nile is at the See also:head of all rivers as regards the length of its See also:basin, which extends through 35° of See also:latitude or 2450 M. in a See also:direct See also:line, with a waterway of about 4000 M . The Nile proper, i.e. from the outlet at See also:Victoria See also:Nyanza to the See also:sea, is 3473 M. See also:long . 1 General Alexi A . Tillo (1839-1900), See also:Russian scientist and geographer, author of See also:works on See also:geodesy, See also:meteorology, &c . A as B Q 3f D 46' 2 L -f =ilk ~" 1 ,S _Ku ra , 1 1 2 as NILE BASIN Blrk. j 1r _ = { Engllish See also:Miles Mir Ira:* Heil AI[See also:aPt See also:Oasis Mtdfiet el-See also:Fayum • ,°e,~ _oasisEdru •. o See also:ode':o= Faraifra1`.~' Oasis t~r_., . I b a n y Oakh/See also:a4 •,w Oasis`'' •iD larva . ps~,u •• See also:Kena . • . . . Oasis FilmBe 8 T•o tc of See also:Cancer let . Catarw t See also:Assuan ar' ..

_-__ij_, 0 e a e r Namara ... Nile Darn ---=_=- - • t _ • . 2ed.Cataracr See also:

Wadi Hato ~ ~=tna___ G Sajlma rt i N l/. b I a n L Oasis '.' • I - • _ _ . D e s e r t 4 ..~~ . 3rd.See also:Cataract See also:Abu Hawed tlk • xort=3udsn-- t5 is •• -_ 4ta . • ,•• ataract rr((//__j "Merawt ---th.Catar'See also:abT A a • See also:Berber•% y ! r Ed See also:Dame -Ps 4 'ir See also:Island .,.- See also:Omdurman . - (6th.Cetaaraotlls ---': hartum of A E L . o R .r Soak nT ~ =--- ,•, -- = = - °1 - ~ . m , . Y, assaw Y r `.• ~S •r, .•' zMcroe Ma rb~ K o d o f a n _ e<^ aAdowa g • El ObeiAe Abbo A %ASO o -" 6 b° ~,.. i coil See also:Aeon om: - * See also:Gonda %Da w x oQ ~1~ D f~ Msand ° • ` aat Cttfpt Famaka {~ ~i(r f a C'D•ar F e s PL t h J 7 ! M 3 6otass c Tj nrr 8 e,-) Stu .

r*M f, ' elZ• do - , L°/ eAhr el-Arob of '0o°° .1 .. P. c °' a' • ;Nassfr t,~ o of , - me no. re, Kek . a\ y~ lio r eo Flak :j : ail} L See also:

ado .. j . 0: See also:tea . G • - _ Reja .:' onoko: - Lake See also:Stefanie • Italk eley • — Lake T . % Ar • . / ~q, ' • :' • • E welle . • ~• i oR pdo ~a'rro a• Fem.•. oaat . Pl ts ol See also:fry ' ` B „oy !I:k Ar L _ ' &See also:vote ° 'rrnoq r'~” . _ tor:: Cho • i .• . +• i See also:Nora Yrs~ '"f71, r enzwrt r ,or' •~ + A . 1111 .

_ 7Fe la& _ a ` • • O°,r F_ ator 8 ils °:° l Aibertfdaard_-'e • • • a L . See also:

Tanganyika •• k See also:Kenya to K Lake o i 1 d •r i tc one,a r • . ? M1~ ' L,Ratran • 8 .led1 •,i , , Y • i .•-• iiimanjaror 4 t . Sao* Namara A ss B See also:Longitude East 3o° of See also:Greenwich C D Bmory w.ltrr sc.693 The Name.—The See also:early Egyptians called his river by a name which was probably Ironounced Hap . It seems to be contected with a See also:root meaning " concealed," ` mysterious." This survived as a religious lesignation down to the fall of paganism. he " See also:great river " was also a frequent lame for the See also:main stream, and this ecame the usual name of the Nile in See also:ate times as Ier-'o and continued in use tmongst the See also:Copts . In the See also:Bible the vile is regularly named YeOr CM', IN'), rom the contemporary See also:Egyptian Yor, ` river." The origin of the See also:Greek and See also:oman name NeIXor, Nilus, is quite lnknown . Alyan:7os in the Odyssey is he name of the Nile (masc.) as well as if the See also:country (See also:fern.) . The See also:Arabs preerved the classical name of the Nile in he, proper name En-Nil ,).;;:,11, or Nil- Misr ,),,j, the Nile of Misr (See also:Egypt) . The same word signifies See also:indigo.' The See also:modern Egyptians commonly See also:call the river El-See also:Bahr, " the sea," a See also:term also applied to the largest rivers, and the inundation " the Nile," En-Nil; and the modern Arabs call the river Bahr-en-Nil, " the river Nile." Basin of the River.—The Nile See also:system is a See also:simple one with three See also:principal divisions: (i) the main stream See also:running See also:south to north, and fed by the great lakes of East Central Africa; (2) the See also:equatorial tributary rivers draining the country north-east of the See also:Congo basin; (3) the Abyssinian affluents . The extent of the basin of the Nile is clearly indicated on the See also:map . Its area is estimated at 1,107,227 sq. m., which compares with the 1,425,000 sq. m. area of the Congo basin . The smaller basin of the longer river is due to its narrowness when passing through the See also:Sahara .

South-See also:

ward the basin includes the See also:northern See also:part of the plateau between the two, " Rift " valleys which See also:traverse that part of Africa, and also that portion of the Albertine (or western) " Rift " valley which lies north of the See also:Mfumbiro mountains . That part of the plateau within the Nile basin is occupied by the Victoria Nyanza and its affiuents . These affluents drain a comparatively small part of this plateau, which stretches south to Lake See also:Nyasa . The most remote feeder of the Nile in this direction does not extend farther than 30 20' S . See also:West and W.S.W. of Victoria Nyanza, however, the Nile basin reaches 3° 5o' S . (264 M. south of the See also:equator) and 29° 15' E., following the See also:crest of the hills which dominate the north-eastern shores of Lake Tanganyika and the eastern shores of Lake See also:Kivu . Turning north-westward from this point the Nile basin crosses the mountainous region of Mfumbiro and includes that of See also:Ruwenzori . Its limit is marked by the western See also:wall of the 1 "En-Nil is the river (lit. the inundation) of Egypt: Es-Saghani says—' But as to the nil [indigo] with which one dyes, it is an See also:Indian word Arabicized' " (The Misbhh of El-Fayumi): Albertine Rift valley, in which See also:lie the See also:Albert See also:Edward and Albert Nyanzas . For a considerable distance the See also:water-parting between the Congo and the Nile is See also:close to the Albert Nyanza and to the Nile as it flows from that lake, but not far north of See also:Wadelai (2° 46' N.) the hills recede and the Nile basin expands westward, over the wide area drained by the Bahrel-Ghazal and its tributaries . In this region there is no well-marked See also:watershed between the Congo and Nile systems, which interlace . Farther north the limit of the valley is marked by the hills of See also:Darfur . Below that point the valley of the Nile extends but a mile or two into the See also:desert .

The south-eastern limits of the Nile basin extend nearly to the western escarpment of the eastern Rift valley—the dividing plateau being a narrow one . North of the equator a See also:

bend is made westward to Mt . See also:Elgon, which on the north-east sends its water towards Lake See also:Rudolf . From Mt . Elgon the Nile watershed is some distance to the west of that lake, while to its north a turn is made again, the watershed including a great part of the Abyssinian See also:highlands . Beyond 15° N. it follows a line generally parallel to the west See also:shore of the Red Sea, except where diverted to the west by the basin of the Khor Baraka . See also:Sources of the Nile.—The question of the sources of the Nile opens up a See also:time-honoured controversy (see under See also:Story of See also:Discovery below) . Victoria Nyanza (q.v.) is the great See also:reservoir whence issues the Nile on its long See also:journey to the Mediterranean . But if the source of the river be considered to be the most remote headstream (measured by the windings of the stream), the distinction belongs to one of the upper branches of the See also:Kagera . Among the feeders of Victoria Nyanza the Kagera is by far the most important, both for length of course and See also:volume of water carried, draining the region of greatest rainfall See also:round Lake Victoria . Three See also:chief branches unite to See also:form the Kagera, and of these the most important for the volume of water carried is said to be the Nyavarongo . The Nyavarongo is formed by the See also:union of various See also:mountain streams, the Rukarara and the Mhogo being the chief .

The Rukarara rises in about 2° 20' S., 29° 20' E., at an See also:

elevation of some 7000 ft., in a picturesque and bracing region immediately east of the Albertine Rift valley . The Nyavarongo first flows north to about I ° 40' S., then turning in a See also:sharp bend east and south, and on again reaching 2° 20' S., unites with the Akanyaru just west of 30° E . The Akanyaru, which comes from the south-west, has been sometimes considered the larger stream, but according to Dr See also:Richard Kandt it carries decidedly less water, while its course is shorter than that of the Nyavarongo . The combined stream takes an easterly and southerly direction, flowing in a swamp valley and joining a little west of 31° E. the third See also:branch of the Kagera, the Ruvuvu, coming from the south . The source of the Ruvuvu is in about 2° 55' S., 29;° E., but its most See also:southern tributary, and the most distant stream sending its See also:waters towards the Nile, is the Lavironza . The Lavironza rises in about 3° 45' S., 29° 50' E., and flows north-east, joining the Ruvuvu, which has hitherto had an easterly direction, in about 30° 25' E., 3° to' S . From this point the Ruvuvu flows east and north to its junction with the Nyavarongo . From this confluence the combined stream of the Kagera flows north and north-west in a level valley strewn with small lakes until almost 1 ° S., when it turns east, and finally empties itself into Victoria Nyanza just north of I° S., the mouth forming a small projecting See also:delta . Its See also:lower course is navigable by shallow See also:draught steamers . The See also:total length of the Kagera, reckoning from the source of the Nyavarongo, is some 430 M . Its volume is stated to vary between 21,000 and 54,000 cub. ft. per second . All the other feeders of Victoria Nyanza are small and often intermittent rivers, the largest being probably the Nzoia, which enters on the north-east from the plateaus south of See also:Mount Elgon .

(The rivers which enter Albert Edward and Albert Nyanzas and, with those lakes, form the western sources of the Nile, are dealt with under ALBERT NYANZA and ALBERT EDWARD NYANZA.) The Victoria or See also:

Somerset Nile.—The See also:ridge of high See also:land which forms the northern shore of Victoria Nyanza is broken at its narrowest part, where the pent-up waters of the lake—through which a See also:drift from the Kagera inlet to the Nile outlet is just perceptible—have forced a passage at the northern end of a beautiful See also:bay named See also:Napoleon Gulf . At this spot, 30 M. north of the equator, at an See also:altitude of 3704 ft., the Nile issues from the lake between cliffs 200 and more ft. high with a breadth of some 500 yds . The See also:scene is one of much grandeur . The escaping water precipitates itself over a rocky ledge with a clear fall of 161 ft . The falls, some 300 yds. across, and divided into three channels by two small wooded islands, are named the See also:Ripon Falls, after See also:Earl de See also:Grey and Ripon (afterwards 1st See also:marquess of Ripon), See also:president of the Royal See also:Geographical Society in 1859 . The Victoria or Somerset Nile, as this See also:section is called, has at first the See also:character of a mountain stream, racing swiftly through a rocky channel often walled in by cliffs (at times 18o ft. high) and broken by picturesque islands and countless rapids . It receives the waters of several streams, which, rising within a few miles of the Victoria Nyanza, flow north . For 133 M. its course is N.N.W.,when, on being joined by the river Kafu (on which Fort Mruli stands), about 1° 39' N., 32° 20' E., it takes the north-east direction of that channel, and it is not till 2° N. that the river again turns westward towards the Albert Nyanza . Seventy miles below the Ripon Falls the Nile enters a marshy lake of irregular outline, running mainly east and west, and known as Kioga (or Choga) . The current of the Nile is clearly discernible along the western shore of this lake, which is 3514 ft. above the sea . Eastwards the lake breaks into several long arms, which receive the waters of other lakes lying on the See also:plain west of Mount Elgon . One of these, named Lake See also:Salisbury, lies in 1 ° 40' N. and 34° E.; east of this lake and connected with it is Lake Gedge .

Lake Kioga also receives the Mpologoma, a river which rises in the foothills of Elgon and flows east and north, attaining a width of 11 m.; and from the south (west of the Nile) a broad lacustrine river, the Seziwa . The Kioga lake system, lying north of the ridge which separates it from Victoria Nyanza, owes its formation in part to the waters pouring down from the Nyanza, and is in the nature of a huge Nile backwater . The lake itself is rarely more than 20 ft. deep; its greatest length is 85 m.; its greatest width to m . Below Mruli, the fall in the See also:

bed levels of the Nile, which up to this point has been comparatively See also:gradual, increases considerably . At Karuma, where the western bend to the Albert Nyanza is made, the river falls over a wall-like ledge of See also:rock, 5 ft. high, which extends across its bed . But the great feature of the Victoria Nile are the See also:Murchison Falls (named by See also:Sir See also:Samuel See also:Baker, their discoverer, after Sir See also:Roderick Murchison, the geologist), situated in 2° 18' N. and 310 50' E . At this point the river rages furiously through a rock-See also:bound pass, and, plunging through a cleft less than 18 ft. wide, leaps about 130 ft. into a spray-covered See also:abyss . Downstream from these falls the river flows for some 14 M. between steep See also:forest-covered hills, a wide and See also:noble stream with a current so slow and steady that, at certain seasons, it is only from the scarcely perceptible drifting of the See also:green water-See also:plants called Pistia Stratiotes that it can be observed . About 24 M. below the Murchison Falls and 254 M. from the Victoria Nyanza the river enters, through a wide delta, and across a formidable See also:bar, the N.E. end of Albert Nyanza . In its passages from the one lake to the other the Nile falls altogether about 1400 ft . Taking its name from a fort which once existed there, the delta See also:district is known as Magungo . From Albert Nyanza to the Plains.—Issuing from the north-west corner of Albert Nyanza some 5 m. from the spot where it entered that lake, the Nile, which is now known as the Bahr-el-See also:Jebel, or Mountain river, flows in a generally northerly direction .

As far as Dufile, 130 M. below Magungo, it has a See also:

gentle slope, a deep channel and a current generally slight . It forms a See also:series of lake-like reaches often studded with reedy islands . Immediately below Dufile the Kuku mountains on the west and the Arju range on the east close in upon the river, which, from an See also:average width of 700 yds., narrows to 230 yds . Here the hills cause the stream to make a sharp bend from the north-east to the north-west . Four or five miles lower down the river widens to 400 yds., and a large island divides the stream, the eastern channel carrying the main volume of water . This island marks the beginning of the Fola Rapids . At its southern end the water falls some 20 ft., and then, like a gigantic See also:mill-See also:race, rushes through a See also:gorge 330 ft. long and nowhere more than 52 ft. wide, to leap Into a deep cavity not more than 40 ft. across . Escaping from this " cauldron " the waters See also:thunder on in a See also:succession of rapids, which extend beyond the northern end of the island. do all the Fola Rapids are nearly 2 M. long . For the next 8o m. the Nile, See also:save for the great volume of water, resembles a mountain torrent, its course interrupted by continual rapids . The last of these occurs at Bedden, where the river breaks through a line of See also:low hills running athwart its channel . One of these hills forms an island in See also:mid-stream . Below Bedden various stations are established upon the river .

Fort See also:

Berkeley, in 4° 40' N . (on the right See also:bank), is the nearest to the rapids . Then follow Rejaf (See also:left bank), See also:Gondokoro (right bank) and Lado (left bank), all within 30 M. of one another . A striking feature of the scenery at Rejaf is a See also:cone-shaped See also:hill, about 370 ft. high, crowned by rocks which have the See also:appearance of the ruins of an See also:ancient See also:castle . At Gondokoro the Nile is clear of the hill country, and enters a vast swamp-like expanse through which it flows with a very low slope and a very tortuous channel . Between Albert Nyanza and the swamp region the Bahr-el-Jebel is joined by many streams . The most important of these affluents is the Asua (nearly 200 M. long), which enters the main stream from the east in 3° 50' N . (19 M . N. of Dufile), but has little water in the dry See also:season . The Asua and its subsidiary streams rise on the western versant of the Karamojo plateau and among the mountain ranges which run off from that plateau to the north-went, the most remote head-stream running originally due south . The Region of Swamps.—The wide valley which the Nile enters at Gondokoro slopes so gradually towards the north that the river falls only some 182 ft. in a stretch of 475 m . Through this valley the river winds in an extremely tortuous course .

Its channel has no See also:

banks, and the overflow has caused extensive swamps which are covered by a See also:mass of See also:papyrus and tall reeds, and are traversed by numerous shallow lagoons or " mayyas." The shape of these lagoons is constantly altering, as also is that of the channels connecting them with the river . About 8 m. below Bor, many of the eastern " spills " unite and form a stream of considerable breadth, with a strong current . This stream, which is known to the Dinkas as the Atem, of the Abai the See also:majority join it on its left bank . The Bashilo, Jamma follows a course generally parallel to the Jebel, being bounded east- ward by forest land . Opposite Kanisa (6° 46' N.), on the main river, the Atem divides into two channels, marshy land extending at this point a great distance to the east . The western branch, or Awai, rejoins the Jebel near Shambe 7° 6' N . The eastern branch or Myding continues through the marshes, eventually joining the Bahrel-Zeraf (see below) in its lower course . Except for the Atem divergence the Nile, despite the swamps through which it passes, maintains a fairly definite course, with a considerable See also:depth of water as far as Shambe, where, to the west, is a large See also:lagoon . Five miles lower down the river splits into two great channels . That to the left, the main stream, continues to be known as Bahr-el-Jebel, but is sometimes called by its See also:Dinka name Kir . The right branch, or Bahr-el-Zeraf (See also:Giraffe river), has a more easterly direction, and does not rejoin the main river until 5o m. below its confluence with the Bahr-el-Ghazal (q.v.) . From the point of bifurcation the Bahr-el-Jebel flows for 230 M. in a general north-See also:westerly direction until it is joined by the Bahr-el-Ghazal coming from the south-west .

The whole region is a vast expanse of low land• crossed by secondary channels, and flooded for many miles in the See also:

rainy season . At the junction of the Bahr-el-Ghazal and the Bahrel-Jebel in 9° 29' N. the permanently submerged area is usually named Lake No, but the Arabs call it Moghren-el-Bohur (See also:meeting of the rivers) . Lake No in the rains covers about 5o sq. m . In the Bahr-el-Jehel occur the great accumulations of " Budd " (q.v.), masses of floating vegetation which obstruct and, if not removed, prevent See also:navigation . The aspect of the river throughout the See also:sudd region is monotonous and depressing . On all sides stretch reaches of the See also:reed known as See also:urn suf or See also:mother of See also:wool (Vossia procera), ambach, Bus and papyrus . These See also:grasses rise 15 to 20 ft. above the water, so as often to close the view like a thick hedge . The level of the See also:flat expanse is broken only at intervals by mounds of See also:earth, erected by the See also:white ants and covered with a See also:clump of brushwood or trees; the moisture in the See also:air is excessive; mosquitoes and other swamp flies swarm in myriads . And yet touches of beauty are not wanting . Water-lilies (Nymphaea stellata and Nymphaea See also:Lotus)—white, See also:blue and See also:crimson—often adorn the See also:surface of the stream . Occasionally the rare and See also:odd-looking See also:whale-headed See also:stork or Balaeniceps rex is met with among the reeds, and at See also:night the scene is lit up by innumerable See also:fire-flies . The White Nile.—From the confluence with the Bahr-el-Ghazal at Lake No, the main stream, which here takes the name of Bahr-el-Abiad, or White river, adopts the easterly course of the tributary stream .

See also:

Forty miles below the point where the Bahr-el-Zeraf reunites with the main branch, the Nile receives its first great eastern affluent—the See also:Sobat (q.v.), whose head-streams rise in the mountains of south-west See also:Abyssinia and the region north of Lake Rudolf . Just above the Sobat junction the Nile resumes its northern course . It passes through a great alluvial plain, stretching from the spurs of the Abyssinian highlands in the east, to the hilly districts of See also:Kordofan in the west, and covered with high grass and scattered See also:bush . The swamps still bound it on either hank, but the river again flows in a well-marked channel with defined banks . About 56 m. below the Sobat mouth, in 9° 55' N., lies (on the left bank) See also:Fashoda (re-named in 1904 Kodok), an Egyptian See also:town founded in 1867 on the site of Denab, the old " See also:capital " of the Shilluks, and famous for the crisis between See also:England and See also:France in 1898 through its occupation by the See also:French officer Marchand . For the next 270 M. the scenery is very monotonous . The river flows in a wide channel between broad swamps bordered by a See also:belt of forest on either bank . At Abu Zeid (about 13° 5' N.) for a distance of nearly 4 M. the river is extremely broad and shallow, being fordable at low water . Fifteen miles lower down, at Goz Abu Gorna—which is the northern limit of the sudd vegetation—the river is divided into two channels by Abba Island, wooded, narrow and 28 m. long . On Abba Island lived, for some years before 1881, Mahommed Ahmed, the See also:Mandi . The Blue Nile.—Five See also:hundred and twenty miles below the Sobat mouth and 1652 m. from Ripon Falls, in 15i' 37' N., the White Nile is joined by its greatest eastern confluent the Bahr-el-Azrak or Blue Nile . In the See also:fork of the two rivers stands See also:Khartum,' the capital of the Anglo-Egyptian See also:Sudan, whilst on the western bank of the White Nile is Omdurman, the former Mandist capital .

The Blue Nile, or Abai as it is called in Abyssinia, rises in the Gojam highlands in i t ° N. and 37 ° E., and flowing northwards 70 M. enters Lake See also:

Tsana (q.v.) near its south-west corner, to issue again at the south-east end . The Abai and its tributaries drain a great part of the Abyssinian plateau . The complicated river system is best understood by a study of the map . The . Abai itself on leaving Lake Tsana makes a great semicircular sweep S.E. to N.W., from the highlands of See also:Ethiopia to the plains of See also:Sennar . In this section of its course its swirling waters See also:rush over a long series of cataracts and rapids, descending from a height of 5770 ft. at the outlet to about 1400 ft. at Fazokl or Famaka (11° 17' N., 35° 10' E.), where it crosses the Abyssinian frontier, and flows through the plains of Sennar to its confluence with the White Nile at Khartum, 1300 ft. above sea-level . Of the tributaries At Khartum the water of the one river is of a greenish-grey See also:colour, that of the other is clear and blue, except when in See also:flood, when it gains a See also:chocolate See also:brown from its alluvial See also:burden . and Muger, which reach the Abai in the See also:order named, drain the country east of the main stream between the basins of the Takazze and the Hawash . The Guder, with a south to north course, rises in the mountains which form the watershed between the Nile and the Lake Rudolf basin . Next comes the Didessa, a large stream rising near the head-waters of the Baro (the main upper branch of the Sobat) and flowing N.W. to the Abai, the confluence being in about to° N., 35° 40' E . It has an early rise and a long flood See also:period, being by far the most important tributary of the Blue Nile . The Dabus or Yabus rises about 9° N., 34° 30' E., and flowing north joins the Abai near the spot where that river breaks through the Abyssinian hills .

All these affluents are perennial, as is the Bolassa or Yesien, a right-See also:

hand tributary which reaches the Abai below the Yabus . Four miles below Famaka the river is joined on its left bank by the auriferous Tumat, an intermittent stream . In Sennar it receives on its right bank two considerable tributaries from the Abyssinian heights, the Dinder, a very long but not perennial stream, and the Rahad, waterless in the dry season, copious and richly charged with sediment during the rains from See also:June to See also:September . At this period the See also:discharge of the Blue Nile rises from less than 200 to over 1o,000 cub. metres per second, thus greatly exceeding that of the White Nile itself, which is only about 800 cub. metres during the floods above the confluence . The length of the Blue Nile is about 850 m . The country, El Gezira, enclosed in the triangle formed by the junction of the White and Blue See also:Niles forms the most fertile portion of the Sudan . It only requires See also:irrigation to render it one of the finest See also:grain-producing areas in the See also:world . The See also:Atbara.—Two hundred miles below Khartum—at Ed-Darner —the Nile is joined by the last of its tributary streams—the Atbara or Bahr-el-Aswad (See also:Black river) . The Atbara, some 800 m. long, rises in the tableland north of Lake Tsana, being formed by the junction of the Angreb, See also:Salaam, Aradeb, Goang and other mountain streams . Making its way towards the Nubian plains, the river flows in a north-westerly direction, joining, in 14° To' N., 36° E., tithe Bahr Setit or Takazze (see ABYSSINIA), a river coming from the east and having a volume of water as large as, if not larger than, the Atbara . The See also:united stream preserves, however, the name of Atbara, and at its confluence with the Nile has a breadth in flood time of over 600 yds . The Atbara and its tributaries, like many of those which feed the Blue Nile, rapidly dwindle after the rains into the smallest limits .

In its lower course the Atbara runs completely dry, but higher up water may be found in deep pools, hollowed out of the See also:

sand bed of the stream by the river when in flood . These pools are full of See also:fish, turtles, crocodiles and hippopotami, which remain imprisoned until the return of the flood . The country comprised between the Nile proper, the Atbara and the Blue Nile is identified with the island of Meroe of ancient See also:history . The Cataracts.—Downstream of the Atbara junction the Nile continues its course to the Mediterranean, traversing a distance of over 1600 m. without receiving a single tributary on either bank . Below Khartum the river makes a great S-shaped bend, and leaving behind the cultivable land pierces the Nubian desert . In its progress the volume of water suffers continual diminution from evaporation, owing to the extreme dryness of the air . The valley of the river is here very narrow, and the desert land in places comes right to the water's edge . Elsewhere high and barren cliffs shut in the valley . Between Khartum and Wadi See also:Haifa (the northern end of the great Lend), a distance of over 900 m., occurs a series of cataracts, known as the 2nd, 3rd, 4th, 5th and 6th (the 1st cataract is lower down the river at Assuan) . That first met with on descending the river from Khartum is the 6th (or Shabluka) cataract . The river here (53 M. below Khartum) is narrow and picturesque . The rapid is 11 m. in length, in which distance the Nile falls some 20 ft.' After 188 m. of smooth water the 5th cataract is reached .

It begins 28 m. below Berber (a town on the right bank at the head of a See also:

caravan route to the Red Sea), and with three principal rapids extends for Too m.—the drop in this distance being rather more, than 200 ft . At the See also:foot of this cataract is the town of Abu Hamed, at the eastern end of the See also:middle of the S bend . The 4th cataract begins 6o m. down stream from Abu Hamed . It is 69 m. long and has a drop of 160 ft . Between the 4th and 3rd cataracts there is a stretch of 194 M. on a very gentle slope (laa- ) . This reach constitutes the See also:province of See also:Dongola, and here the cultivable land on the western See also:side of the river is of greater extent than usual in the desert See also:zone . The 3rd cataract, 45 M. long, has a drop of some 36 ft . After another smooth reach extending 73 M. the 2nd cataract, which ends just above Wadi Haifa, the northern frontier town of the Anglo-Egyptian Sudan, is reached . This cataract is 124 M. long and has a fall of 216 ft . Between the 2nd cataract and Assuan are 214 M. of smooth water with a scarcely perceptible slope, TS b-a . The average breadth of the river here is 1640 ft . It runs through a See also:sandstone bed, and the current is guided in many places by spurs of See also:masonry built by the ancient Egyptians .

Lower River and Delta.—For some distance above Assuan the river is studded with islands, including those of See also:

Philae and Elephantine . The rapids south of the town used to form the 1st cataract, where . The fall in the river-bed, as given in these pages, is an approximation derived from barometric readings only . in a length of 3 m., the river See also:fell 164 ft . Since the completion of the great See also:dam and locks at the head of these rapids (Dec . 1902) they have to a certain extent disappeared, and a navigable channel has been formed . The dam, pierced by 180 sluices, stretches across the river—a wall 2000 yds. long and 26 ft. wide at the See also:top . Below the water rushes between rocks in many channels (this being the See also:relics of the cataract) . Upstream from the dam a lake some 100 m. in length has been formed . The Assuan Dam was opened on the loth of See also:December 1902 (see under IRRIGATION) . A See also:ladder of four locks on the western side of the dam permits navigation between the upper and lower reaches . At Assuan the banks of the river are bordered by high See also:granite hills .

Phoenix-squares

From this point to the See also:

apex of the delta the length of the Nile is 605 m. with a slope (iauaa) even slighter than that above Assuan . The valley is comparatively narrow, being an almost level depression in a See also:limestone plateau—the area of fertility ends where the land ceases to be irrigated by the river . At See also:Edfu, 68 m. below Assuan, a barrage, known as the See also:Esna barrage, regulates the flow of the water, and at See also:Assiut, 274 M. below Edfu, is another barrage fulfilling the same purpose . See also:Cairo, the capital of Egypt, is built on the eastern bank of the Nile 12 M. north of the apex of the delta . At the beginning of the delta the Nile separates into two channels, the See also:Rosetta and the See also:Damietta, which join the Mediterranean at its south-east See also:angle . At the bifurcation is a See also:double barrage, by means of which the water can be dammed to the height required for forcing the river into the canals which irrigate the delta . Of the two branches the Damietta is the more easterly . Both are about the same length—146 m.l Behind the