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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: 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: 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: 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: 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: 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. 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 See also:coast-line, which is low and sandy, are a number of See also:salt marshes or lagoons. Whilst the Damietta branch is gradually silting up, the Rosetta branch is scouring out a wider channel. In time of full flood the depth of the water in either branch is about 23 ft. See also:Hydrography.—The fertility and prosperity of Egypt and the northern part of the Sudan being entirely dependent on the irrigation of the land by the waters of the Nile, the variation in the See also:supply at different seasons of the See also:year is of vital importance. (In Egypt the height of the flood has been recorded annually, as the chief event of the year, since at least 3600 B.C.) Above the Sobat confluence the Nile traverses a region of heavy rainfall and the water-supply is super-abundant. It is from Victoria, Albert and Albert Edward Nyanzas and their feeders, and in a lesser degree from the Bahr-el-Ghazal, that this river obtains its See also:constant supply of water throughout the year. The great lakes and the region of swamps, retaining a large proportion of the water they receive, See also:act as natural reservoirs and prevent the lower Nile from ever running dry in summer. The Abyssinian affluents are the chief cause of the Nile flood. In the equatorial regions rainfall varies from 30 to 8o in. during the year with a mean of about 50. It is heaviest in the months of See also:January, See also:February, See also: It is the colour of the Sobat water which gives its name to the White Nile. The Blue Nile, at its confluence at Khartum, begins to rise in June and is in flood from July to October; the Atbara is also in flood during the same months. The great difference in the supply of water from the equatorial regions and from Abyssinia arises from the fact that the first-named district is one of heavy See also:rain practically all the year round; whereas in Abyssinia the season of heavy rain is usually limited to the months of June to September. Reduced to its simplest expression, the Nile system may be said to consist of a great steady flowing river fed by the rains of the tropics, controlled by the existence of a vast head reservoir and several areas of repose, and annually flooded by the See also:accession of a great See also:body of water with which its eastern tributaries are flushed. At Khartum the Nile is' lowest in April and May and highest in See also:August and September. Its minimum depth is 18 ft. and its maxi-mum depth 25 ft. At Assuan the Nile is at its lowest at the end of May, then rises slowly until the middle of July, and rapidly through-out August, reaching its maximum at the beginning of September; it then falls slowly through October and November. At Cairo the 1 In ancient times the delta was watered by seven branches; five of these branches are now canals not always navigable. The ancient branches were, beginning at the west, the Canopic, Bolbitine, Sebennytic, Phatnitic, Mendesian, Tanitic and Pelusiac, of which the modern Rosetta and Damietta branches represent the Bolbitine and Phatniticlowest level is reached about the middle of June, after which the rise is slow in July and fairly rapid in August, reaching the maximum at the beginning of October. By using the water stored by the Assuan dam in the months following high Nile, the river lower down has been, since 1902, replenished at times of low water to meet the needs of cultivators (see IRRIGATION: Egypt). At Assuan the average rise of the Nile is 26 ft., at Cairo it is 23 ft. A rise of 21 ft. only at Assuan is a " See also:bad Nile "; on the other hand, a rise of 30 ft. causes a danger of flood, or rather it used to do so previous to the See also:building of the dam. When the Nile below the swamps is at its lowest, the water acquires a green colour and a putrid See also:taste and See also:smell. This is caused by innumerable microscopic green See also:algae, which are brought into the White Nile from the marshes of the Bahr-el-Jebel and Bahr-el-Ghazal, and descend the river when it is clear of all suspended See also:matter. This "green water " is seen at Cairo about the end of June or beginning of July, and passes away with the first rise in the later See also:month, the algae being unable to live in turbid water. By August the river in lower Egypt is full of dark red-brown sediment brought down by the Blue Nile and the Atbara from the plateaus of Abyssinia. It is estimated to be then carrying 8 cub. yds. per second; by September this has been reduced to See also:half the amount, and then diminishes rapidly. It has been calculated' that the time taken by the water to travel from Khartum to the delta barrage varies from 14 days in September to 42 in May. On the island of Elephantine at Assuan is the famous Nilometer, dating from ancient Egyptian times, altered and extended in See also:Roman times and repaired in 187o by the See also:Khedive See also:Ismail. It is a well built of hewn stones, marked with scales to See also:record the level of the water, which rises and falls with that of the river. The remains of other ancient Nilometers exist at Philae, Edfu and Esna, together with See also:inscriptions recording about forty high Niles in the XXVth See also:Dynasty, discovered on a See also:quay wall of the See also:temple of See also:Karnak. The data furnished by these give about 41 in. per See also:century as the See also:rate at which the Nile is silting up its bed north of the 1st cataract. The level of high Nile at the Semna rapids, between the 2nd and 3rd cataracts, is 24 ft. lower than that indicated, by the marks sculptured c. 2500 B.C. This fall is attributed to the erosive See also:action of the water as it passes over the hard See also:gneiss which at Semna forms a barrier across the stream. The See also:vertical extent of such erosion is equal to about two millimetres a year. It is noteworthy that from the mouth of the Sobat to the Mediterranean the current of the Nile is generally deepest and strongest on its right (eastern) bank; the Nile in this respect resembling other great rivers of the northern hemisphere. The pressure of the water on the right bank is attributed to the prevailing N.W. winds.3 There are now gauges for registering the rise of the water at Cairo, Assuan, Berber and Khartum on the main river; at See also:Wad Medani, Sennar and Roseires on the Blue Nile; El Duem and Taufikia on the White Nile; Nasser on the Sobat; Gondokoro on the Bahr-el-Jebel; and Ugowe, Jinja and Entebbe on Victoria Nyanza. Navigation.—At high Nile there is uninterrupted water-communication from the sea to Fort Berkeley in 4° 40' N.—a distance of 2900 M. Owing to the cataracts, navigation between Assuan and Khartum is impossible during low Nile, and from the 1st of March to the 1st of August the upper courses of the Damietta and Rosetta branches are closed to navigation; the water being utilized for summer irrigation in the delta. As far as See also:Mansura (6o m.) on the Damietta branch and Kafr-el-Zayat (70 m.) on the Rosetta branch, and between Khartum and Fort Berkeley (1090 m.) the river is navigable all the year round, though between the Sobat confluence and Bor, navigation is dependent on the channel being kept clear of sudd. Above Fort Berkeley navigation is interrupted by the rapids and cataracts which extend to Dufile, but from the last-named town to Fajao at the foot of the Murchison Falls (a distance of 150 m.) the river is navigable throughout the year. There is a further navigable stretch between Foweira (just above the Karuma rapids) and the southern- end of Lake Kioga. The Blue Nile is navigable for steamers during flood time from its confluence at Khartum to Roseires at the foot of the Abyssinian hills, a distance of 426 M. At low water small boats only can go up stream. The Atbara is never navigable, the current during flood time being too See also:swift for boats. Including the Sobat and the Bahr-el-Ghazal the navigable waters of the Nile and its afliuents exceed 4000 M. Owing to the cataracts and the partial closing of the Damietta and Rosetta branches for irrigation purposes, the Nile below Khartum is subsidiary, as a means of communication, to the See also:railways and highroads.' Above Khartum the river is 2 By Sir Hanbury Brown, inspector-general of irrigation, Lower Egypt, 1892-1903. 3 Egyptian Irrigation (p. 29), by Sir W. Willcocks (See also:London, 1899). ' Between Assuan (Shellal) and Wadi Halfa the river is, however, the main See also:highway, there being no railway between the places named. the chief channel of See also:trade and See also:commerce. Steamers first ascended the Nile above the cataracts (to Korosko) in 1820. It was not till 1846 that a steamboat was placed on the White Nile. (W. E. G.; F. R. C.)
Story of Discovery.—Few problems in geographical See also:research exercised for so long a period so potent an See also:influence over the imaginations of See also:man as that of the origin of the Nile. The ancient Egyptians, as is apparent from the records on their monuments, were acquainted with the main stream as far south as the junction of the White and Blue Niles. They appear also to have known the Blue Nile up to its source and the White Nile as far south as the Bahr-el-Ghazal confluence. Beyond that point the sudd probably barred progress. The knowledge acquired by the Egyptians passed to the Persians and Greeks. See also:Herodotus (about 457 B.C.) ascended the Nile as far as the First Cataract. He was led to believe that the source of the river was far to the west—in the region of Lake See also:Chad. Eratosthenes, See also:superintendent of the Alexandrian library, in a map made about 250 B.C., showed, with See also:fair accuracy, the, course of the river as far as where Khartum now stands. He showed also the Atbara and Blue Nile. Eratosthenes was the first writer to hint at equatorial lakes as the sources of the river. See also:Juba II., See also: 20), in his Libyca, quoted by See also:Pliny, makes the Nile rise in western Mauretania, not far from the ocean, in a lake presenting characteristic Nile See also:fauna, then pass underground for several days' journey to a similar lake in Mauretania Caesariensis, again continue underground for twenty days' journey to the source called Nigris on the See also:borders of Africa and Ethiopia, and thence flow through Ethiopia as the Astapus. This remarkable story received considerable See also:credence, and may be connected with the theory which made the See also:Niger a branch of the Nile (see below). See also:Strabo (a contemporary of Juba), who ascended the river as far as Syene, states that very early investigators had connected the inundation of the Lower Nile with summer rains on the far southern mountains, and that their theory had been confirmed by the observations of travellers under the See also:Ptolemies. About the same time Dalion, a Greek, is believed to have ascended the White Nile. See also:Nero despatched two centurions on an expedition for the See also:express purpose of exploring the Nile, and See also:Seneca states that they reached a marshy impassable region, which may be easily identified with the country of the White Nile above the mouth of the Sobat. To what they referred when they reported a great mass of water falling from between two rocks is not so readily determined. During this period more accurate knowledge concerning the Nile sources was obtained from the reports of Greek traders who visited the settlements on what is now called the See also:Zanzibar coast. A See also:merchant named See also:Diogenes returning (about A.D. 50) from the east coast of Africa told a Syrian geographer, See also:Marinus of See also:Tyre, that journeying inland for twenty-five days he reached the neighbourhood of two great lakes and a range of See also:snow mountains whence the Nile See also:drew its sources. Marinus published this See also:report in his geographical works. This See also:book is lost, but the See also:information is incorporated in the writings of See also:Ptolemy, who in his book and map sums up all that was known or surmised of the Nile in the middle of the 2nd century of the See also:Christian era. Ptolemy writes that two streams issuing from two lakes' (one in 6° and the other in 7° S.) unite in 2° N. to make the Nile, which, in 120 N., receives the Astapus, a river flowing from Lake Coloe (on the equator). His two southern lakes, he conceived, were fed by the melting of snows on a range of mountains running east and west for upwards of 50o M. —the Mountains of the See also:Moon, rd rigs aeXt vrls ilpos, Lunae Monies. It will be seen that, save for placing the sources too far to the south, Ptolemy's statements were a near approximation to the facts. The two southern lakes may be identified with Victoria and Albert Nyanzas, and Lake Coloe with Lake Tsana. The snow-capped range of Ruwenzori occupies—at least in part—the position assigned to the Mountains of the Moon, with which See also:chain See also:Kilimanjaro and Kenya may also be plausibly identified. On all the subsequent history of the See also:geography of the Nile ' The two lakes afterwards received the names Lake of Crocodiles and Lake of Cataracts. Ptolemy's theory had an enormous influence. See also:Medieval maps and descriptions, both See also:European and Arabian, reproduce the Mountains of the Moon and the equatorial lakes with a variety of probable or impossible modifications. Even See also:Speke (see below) congratulated himself on identifying the old Ptolemian range with the high lands to the north of Tanganyika, and connected the name with that of See also:Unyamwezi, the " country of the moon." In the fourteen centuries after Ptolemy virtually nothing was added to the knowledge of the geography of the Upper Nile. Arab writers of the 12th and 13th centuries make mention of the great lakes, and their reports served to revive the See also:interest of See also:Europe in the problem of the Nile. See also:Idrisi made both the Nile and the Niger issue from a great lake, the Niger flowing west, the Nile north. Hence arose much confusion, th : See also:Senegal See also:estuary being regarded by its discoverers (1445) as the mouth of a western branch of the Nile. Even until the early years of the 19th century the belief persisted in a connexion between the Nile and the Niger (see further NIGER). Portuguese explorers and missionaries, who in the 15th and 16th centuries visited the east coast of Africa and Abyssinia, gained some information about the equatorial lake region and the Nile,2 the extent of the know-ledge thus acquired being shown in the map of Africa of Filippo Pigafetta, See also:Italian traveller and historian (1533–1603) published in 1580. It was not, however, till the 17th century that the sources of the Blue Nile were visited by Europeans. In 1615 Pedro See also:Paez, a Portuguese See also:priest, was shown them by the Abyssinians. Ten years later another Portuguese priest, Jeronimo See also:Lobo, also visited the sources and left a vivid description of the rise of the river and its passage through Lake Tsana. An See also:English version of the accounts of Paez and Lobo—written by Sir See also:Peter Wyche—was published in 1669 by order of the Royal Society, of which Sir Peter was an See also:original See also:Fellow. Between 1625 (the date of Lobo's visit) and 1770, some attempts were made by French and other travellers to explore the Blue Nile, but they ended in failure. In the last-named year See also: The Englishman W. G. See also: Then followed three Egyptian expeditions sent in 1839–41 and 1842 by Mehemet Ali up the White Nile. The first expedition reached, on the 28th of January 1840, a point 6° 3o' N., the second and third pressed further south, reaching 4° 42' N.—or the foot of the rapids above Gondokoro. A See also:Turkish officer, See also:Selim Bimbashi, commanded the expeditions, and among the members were the Frenchmen See also:Thibaut (a convert to See also:Islam and for nearly forty years French consular See also:agent at Khartum), D'See also:Arnaud and See also:Sabatier, and a See also:German, See also: Speke (q.v.) discovered the large nyanza (lake), which he rightly conceived to be the head reservoir of the White Nile, and which in honour of the See also:queen of England he named Victoria Nyanza. See also:Captain (Sir Richard) See also:Burton and Speke had gone inland from Zanzibar to investigate the reports concerning the vast lake which Rebmann and Krapf had called the Sea of Unyamwezi. These reports proved to be exaggerated accounts of three distinct lakes—Nyasa, Tanganyika and Victoria Nyanza. In 186o Speke returned to Zanzibar accompanied by J. A. See also: Here Speke and Grant left the river, and travelled overland east of the stream, which they did not strike again until just above the Ausa confluence. Thence they travelled down the Nile to Gondokoro, reached on the 15th of February 1863. This remarkable journey virtually solved the Nile problem so far as the source of the main stream was concerned, but there remained much to be done before the hydrography of the whole Nile basin was made known. At Gondokoro Speke and Grant met Mr (afterwards Sir Samuel) Baker' and his wife—a Hungarian See also:lady—who had journeyed thither to afford the explorers help. To Baker Speke communicated the See also:news he had heard concerning the western lake, and this lake Baker determined to find. On the 26th of March 1863 Baker and his wife left Gondokoro, and despite much opposition, especially from slave-dealers, followed, in the See also:reverse direction, the route of Speke and Grant as ' Baker and his wife had in 1861–1862 explored the Atbara (to its upper waters) and other eastern tributaries of the Nile.far as Unyoro, whence they journeyed west. On the 14th of March 1864 they struck the lake (Albert Nyanza) on its S.E. side. They paddled up the lake to the point where a large river coming from the east poured its waters into the lake. This stream, which they rightly conjectured to be Speke's Nile, they followed up to the Murchison Falls. Thence they went overland to the Karuma Rapids, and so back to Gondokoro by their old tracks. It fell to the See also:lot of General C. ,G. See also:Gordon (when that officer administered the Egyptian Equatorial provinces) and his assistants to fill up the See also:gap left by Speke and Baker in the course of the main stream. In 1874-75 two English engineer See also:officers—Lieut. (afterwards See also:Colonel Sir See also: (At the time of his visit the snow-peaks and glaciers were hidden by heavy clouds.) In 1888, however, Stanley saw the mountains in all their See also:glory of snow and See also:ice, discovered Albert Edward Nyanza, and traced the river (Semliki) which connects it with Albert Nyanza. The Semliki had been discovered, and its lower course followed in 1884 by Emin Pasha. Thus at length the riddle of the Nile was read, though much was still to do in the matter of scientific survey, and in the exploration of the valley of the Sobat (q.v.). The Kagera had been partly explored by Stanley (1875), by whom,it was called the Alexandra Nile, and between 1891–98 its various branches were traced by the German travellers Oscar Baumann, Richard Kandt and Captain H. See also:Ramsay, and by Lionel See also:Deck, a Frenchman. A British officer, Colonel C. Delme-See also:Radcliffe, made the first accurate survey (1900–19o1) of the Nile between Albert Nyanza and Gondokoro. In 1903 an Anglo-German See also:commission under Colonel Delme-Radcliffe and Captain Schlobach made a detailed survey of the Kagera from 300 E. to its mouth. The Kioga system was surveyed in 1907–1908 by Lieut. C. E. Fishbourne. A trigonometrical survey of the upper river was begun by Colonel M. G. See also:Talbot, director of Sudan surveys, in 19oo, and other surveys were made by Captain H. G. See also:Lyons, director-general of the Egyptian survey See also:department. A fish-survey of the waters of the Nile was also undertaken. The Removal of Sudd. -As already stated, the sudd above the Sobat confluence seems to have stopped the Roman centurions sent by the See also:emperor Nero to explore the Nile. When the river above the Sobat was again reached by white men (184o) the stream was clear of sudd, and so continued until 1863–1864, when both the Bahr-el-Jebel and the Bahr-el-Zeraf became blocked by floating masses of vegetation. When Baker proceeded to Gondokoro in 187o he thus described the increase that neglect had caused in the obstruction: " The immense number of floating islands that were constantly passing down the stream of the While Nile had no exit; thus they were sucked under the original obstruction by the force of the stream, which passed through some mysterious channel, until the subterranean passage became choked with a wondrous See also:accumulation of See also:vegetable matter. The entire river became a See also:marsh, through which, by the great pressure of water, the stream oozed through innumerable small channels. In fact, the White Nile had disappeared." Baker, who had to cut through 5o m. of sudd in his passage to Gondokoro, urged to Khedive 2In the map issued in 1873 to illustrate See also:Schweinfurth's book, The See also:Heart of Africa, Victoria Nyanza is shown as five small lakes. Ismail to reopen the Nile. This work was efficiently done by Ismail Ayub Pasha, and the White Nile was clear for large vessels when Gordon reached Khartum in 1874. The river did not long remain See also:free, for in 1878 Emin Pasha was unable to ascend the Bahr-el-Jebel from the south on account of sudd. It was cleared in 1879–1880 by officials in the Egyptian service, but had again accumulated in 1884. In consequence of the Mandist See also:movement nothing could then be done to clear the river, and the work was not taken in hand again until 1899, when, by direction of Sir See also: Beyond this point for a distance of 25 m. the Bahr-el-Jebel could not be traced, so completely was the channel choked by sudd. In 1902, however, Major G. E. See also:Matthews discovered the true bed of the river, which by 1904 was completely freed from obstructions, and freedom of navigation between Khartum and Gondokoro was permanently secured. The effect of the sudd-cutting operations on the supply of water available for irrigation purposes In the lower river was slight. Nevertheless, Sir William Garstin reported that the removal of the sudd " undoubtedly checked the fall in the river levels which would otherwise have taken See also:place." See also:Political Relations.—Explored in part by Egyptian See also:government expeditions, the upper Nile as far south as Albert Nyanza became subject, between 184o and 1882, to Egypt. See also:Possession of the greater part of the river above Wadi Halfa then fell to the followers of the Mandi. In 1896-98 an Anglo-Egyptian See also:army reconquered the country, and from Victoria Nyanza to the Mediterranean the main river came under British or Egyptian See also:administration. The west bahk of the Bahr-el-Jebel, as far north as 5° 30' N., was in 1894 taken on See also:lease from Great See also:Britain by the Congo Free See also:State during the See also:sovereignty of See also:Leopold II., the territory leased being known as the Lado See also:enclave (q.v.). The Kagera, the main headstream, lies almost wholly in German East Africa. The study of the See also:zoology of the Nile valley was the See also:special object of a See also:Swedish scientific expedition in 1901, under the direction of Prof. L. A. Jagerskiold. The Results were published at See also:Upsala, pt. iii. appearing in 1909. For the botanical and other aspects of the Nile valley, see the works of Petherick, See also:Heuglin, Schweinfurth, See also:Junker and Emin. An orographical map of the Nile basin was published by the Survey Department, Cairo, in 1908. It is in six sheets on a See also:scale of 1: 2,500,000, with inset maps showing political divisions, See also:distribution of rainfall and of vegetation. (F. R. Additional information and CommentsThere are no comments yet for this article.
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