The Nile in 1904

Taking these quantities and calculating directly for the filling of the trough from the gauges themselves, I have collected in Tables 50 to 52, the Cairo gauges corresponding to the Assuân gauges for the high years 1874 and 1878 and the minimum year 1877. As far as the more important results are concerned, I tabulate them here:—

Gauges at Assuân and Cairo.

To enable one to compare these figures which are in metres and referred to mean low water level, with the gauges as recorded at present, I add the following table:—

The flood of 1874 was an early one and the basins were discharged on a falling Nile, still they raised the Cairo gauge to 8·7 metres on the 5th October while it would have risen to 8·5 on the 15th September with perennial irrigation. The flood of 1878 was an exceedingly late one and the basins had to be discharged while the river was still very high. By the 10th October, the river had risen to 8·7 metres at Cairo when the banks were breached and all future rise stopped. With perennial irrigation, the maximum gauge of 8·6 metres would have been reached on the 10th October. The flood of 1892 was at Assuân 10 centimetres below that of 1874 and 20 centimetres below that of 1878, and midway between them in point of time. It was also under complete control owing to the new regulating works on the basins. It rose to 8·4 metres at Cairo on the 5th October and fell exceedingly slowly. With perennial irrigation, it would have risen to 8·4 at Cairo on the 30th September and then fallen rapidly.

Speaking generally, we may say that with perennial irrigation the very high floods at Cairo will be 15 days in advance of what they are at present, that they will not rise higher, and that they will fall 15 days earlier than what they do now. With low floods there will be no appreciable difference as to date, but the floods will be slightly higher at Cairo. In ordinary floods, there will be an advance of from 20 to 25 days in the date of the maximum flood, and a maximum gauge at Cairo 50 or 60 centimetres under the maximum gauge at Assuân. We have so far considered Cairo only, as the Delta proper depends on the Cairo gauge. We now turn to the Nile in Upper Egypt itself: south of Sohag, there will be no serious change in levels, but the Sohagia and Ibrahimia canals between them carry at present 750 cubic metres per second in excess of what they would carry if there were perennial irrigation in Egypt, and the greater part of this water is not returned to the Nile until the Kushesha escape is reached. The reach of the Nile from Sohag to Kushesha is the one which will experience the greatest changes, and I calculate that there will be a rise of 40 centimetres as compared with the maximum gauges under basin irrigation.

It will be noted that at the beginning of this paragraph I stated that “the perfection of the perennial irrigation of the Delta north of Cairo will in no way affect the Nile in flood.” This had reference only to the quantity of water taken from the Nile in high floods. There is however one very serious aspect of this question. The regulation on the Barrage in low floods, which has gone on steadily since 1899 when Sir Hanbury Brown used the Barrages in flood for the first time, has enormously increased the value of the works, but it has certainly caused the Main Nile to silt, and probably also the branches, owing to a reduced discharge and velocity of the silt-bearing water, whose capacity to carry on that quantity of silt depends on its velocity. It seems to me that unless steps are taken to insure the scouring out of this silt by the clear water of November, December and January the consequences will be very serious. High floods scour out their beds, but if a very high flood were to come early before the silt had been scoured out, it might overflow the banks near Cairo or in the middle reaches of the Nile branches in the Delta.

Sir William Garstin has estimated the cost of converting the existing basins of Upper Egypt into perennially irrigated land at £7,000,000, thus made up:—

The resulting land tax from the improved irrigation in Upper or Lower Egypt he has estimated as follows:—

39. Development of the Sudan.

—Lord Cromer’s wise decision to construct the Suakin-Khartoum railway immediately and the Abu Hamed-Dongola railway as soon as possible, is the charter of the development of the Sudan. With these railways and especially the former in working order, we can arrange for irrigation works for the production of cotton and wheat for export, knowing that they can be exported at a cost of transport which will not be absolutely prohibitive. The soil of the Sudan along the Blue Nile, the Atbara, the Main Nile and a great part of the White Nile is the same as that of Egypt itself. It has all come from Abyssinia. When at Khartoum last February, I collected specimens of typical Gezireh soil from points 10 miles south of Khartoum and from near Khartoum itself. They were analysed by Mr. Frank Hughes and reported on by Mr. Foaden.

The specimens were numbered as follows:—

(1) Typical Gezireh soil from a point 10 miles south of Khartoum near the Blue Nile.

(2) Typical Gezireh soil from a point 2 miles south of Khartoum near the White Nile.

(3) White Nile side under cultivation in 1904.

(4) White Nile side below flood level.

(5) Blue Nile side, not so common as (1).

(6) The sandy soil generally within 5 miles of Khartoum.

Nos. 1, 2, 5, and 6 are above high flood level of both Niles.

“The nitrogen and salt were determined in the samples, as received, without drying.

“All contain abundance of carbonate of lime; Nos. 1 and 2 might almost be called calcareous. All gave a strong reaction for phosphoric acid, and there is therefore every reason to believe that they are rich in this ingredient. So far as the texture of the soils is concerned, little can be said except that they differ from those previously examined for Kena Mudirieh, in containing a large amount of coarse sand 1-3 m.m., which is entirely absent in most Egyptian soils; No. 6 would probably be too light for agricultural purposes in its present condition.

“The nitrogen is as high as one would expect but is lower than is necessary for fertile soils. It would be necessary therefore to encourage the growth of leguminous crops to increase the quantity of nitrogen in the soil and to employ nitrogenous manures. It must be borne in mind that in soils of this class the nitrogen is usually in a highly insoluble and un-nitrifiable form.

“The salt is in no case high; 0.25% is usually considered to be the limit for satisfactory growth; all the samples are well below this limit.”

I had complete analyses made of numbers (1) and (2). The results were as follows:

Though none of these specimens contained salt in excess, Nile deposit in certain localities has very large proportions of common salt and sulphate of soda. The dark soil near the Atbara mouth at El-Damer is largely exploited for common salt, while similar soil south of Khartoum is free from it.

The extent of this Nile deposit soil is very great indeed and if irrigation could be assured, there would be a great future before the Sudan.

In Mr. Dupuis’s Report which is the last appendix to Sir William Garstin’s Report, he speaks of this soil as being met with on the Blue Nile, on the Rahad, on the Atbara and on the Gaash. From Khartoum northwards the main Nile flows between berms of this soil.

The extent and quality of this soil may therefore be considered as an undisputed asset of the Sudan. We have next to consider the seasons.

A reference to tables 76, 77, and 80 will show how much warmer the Sudan is than Egypt, and any attempt to introduce Egyptian methods into the Sudan without modifications will not at once turn the Sudan into Egypt. I allow that extensive plains of irrigated land greatly moderate the heat as they have already done in Middle Egypt; but we have to begin from the beginning in the Sudan, and there are no extensive plains of irrigated land. Basin irrigation will be a failure in the Sudan unless it is supplemented by two or three waterings in the winter, for all crops except the cheapest and coarsest leguminous crops. Wheat must be irrigated in winter whether sown in a basin or on the Nile berm, except in a few choice, low and damp localities. Cotton, on the other hand, which has to be sown in spring in Egypt and reaped in autumn will need such an extraordinary quantity of water to pull it through the summer that it will be found preferable to grow it in June with the rising flood and reap it at the end of the winter. Irrigation therefore from June to October for Indian corn, from June to February for cotton, and from November to February for wheat will be essentials of a good harvest in the Sudan.

We now come to the question of the water supply. Unless permits are given for pumps to work from the 15th June to the 15 February, the cultivation of cotton and wheat on any scale in the northern part of the Gezireh, along the main Nile between Khartoum and Dongola, and on the lower reaches of the Atbara will be out of the question. Maize and millets and some of the coarser leguminous plants might be developed by pumps with permits to work from 15th June to 15th October, but it would pay no one to put up pumps on these terms.

Fortunately for the joint interests of Egypt and the Sudan, though Egypt cannot spare water between the 15th March and 30th June, which would correspond to 1st March and 15th June in the Sudan; she has enough to spare for pumps at other times, though she has not always enough to spare for large free flow schemes in the Sudan. Free flow schemes in the Sudan, except during high and good floods, have however yet to be found.

Speaking generally we may say that the agricultural success of the Sudan will depend on permits for pumping engines to work between the 1st June and the end of February. There should be no difficulty in the way of such permits being given. We have spoken so far of schemes within the power of individuals and companies. Of schemes which the Government alone could carry out by itself or in conjunction with powerful companies, the most promising seem to be those which are connected with the 6th cataract. This cataract seems well suited for the construction of a solid dam to create power and develop electricity to work pumps between it and Khartoum, and some 30 kilometres up the Blue Nile; and if possible to allow of a canal down the left bank of the Nile as far as Berber. This project might be studied with advantage and a greater amount of water storage for summer use be also obtained.

Another scheme is the construction of a double barrage and weir near Wad Medani on the Blue Nile, with canals irrigating the Gezireh and the right bank of the Blue Nile and the Nile to Shabluka. Unfortunately no cross sections have been taken of the Blue Nile showing how high the Gezireh is above the bed and water surface of the Blue Nile at Wad Medani. A weir further south would, as Mr. Dupuis states, entail very expensive canals to irrigate the lands south of Khartoum.

Mr. Dupuis’s report on the Atbara is not very hopeful. Without reservoirs this torrential river could insure no crop except millets and Indian corn. The same may be said for the Gaash. Basins without winter irrigation would, I think, be most unsatisfactory.

Examining Mr. Dupuis’s figures and sections for the outlet of lake Tsana, I calculate that this reservoir would not supply a fraction of the water estimated by Mr. Dupuis. If I were wrong, and I should be pleased indeed to be wrong here, a tunnel along the alignment roughly surveyed by Mr. Dupuis, Plate XX, leading the waters of Lake Tsana into the Rahad river, and from there under the Blue Nile by a syphon, and branch canals irrigating both banks of the Rahad and both banks of the Blue Nile to Khartoum, would be one of the boldest projects in the world.

It will be noted that no mention has been made of the tracts between the foothills of Abyssinia and Wad-el-Medani which can produce good crops of Indian corn, millets and even cotton in nine years out of ten with the aid of rain without irrigation. If the land could lend itself to basins similar to those of Bundelkund or to river fed pans as in Madras, a development of this country would be possible. Ordinary Egyptian basin irrigation would be, I think, of no use.

The following quotations from a letter written by Messrs. Choremi, Benachi and Co., of Alexandria, to Mr. Foaden on the 8th February 1904, will give an idea of the estimation in which Sudan grown cotton is held in Alexandria:—

“The cotton generally is good and superior to any Sudan cotton I have yet seen. Last year the best I saw was sent by the Sudan Government and grown in Miralai Stanton Bey’s garden, with artificial irrigation and quality was (first picking) class “good”, equal to Beni-Suef or Minieh cotton, but more woolly. In any case it is saleable cotton for coarse Nos. of Yarn, not what we call Bolton Spinners’ cotton.

“I now give you the following classification and values compared to Standard of Full Good Fair Lower Egypt which is the basis of “Futures” in our Market and Liverpool.

“On Upper Egypt the outturn in ginning on basis 315 lbs. per cwt. in seed runs from 100 to 104, and Lower Egypt 105-110 according to province grown and quality of seed.

“From the above report you will see that quality generally is good—but I regret the seed got mixed—probably through mistakes in transport or if in single bags some broke and seed became mixed.

“The outturn in ginning I consider good and the seed I notice deteriorates but very little as you can see—though with that of Stanton Bey’s I examined with you last year, the deterioration was, if I remember right, something like 10% in one year. The seed from the non irrigated Sudan (I suppose near Khartoum) though from good Afifi seed, almost becomes unfit for sowing and the quality of this cotton had a very poor outturn of about 73%.

“Rain crops cannot be depended on, because if no rain for some time the quality will be totally spoilt.

“I fail to find any trace of sand in the samples—though the common Sudan non-irrigated cotton was very dirty and sandy.”

The following extracts from a letter written to me by Ibrahim Effendi Fahmy, originally a student of the Cairo Agricultural College and at the time of writing Government agriculturist at Khartoum and on leave in Cairo, will be found interesting.

“There are three seasons in the Sudan, which are different from those in Egypt. The seasons are:—1st the winter which extends from the 1st November to the end of February, in this season wheat, beans, barley, onions, Indian corn and millets are planted: 2nd, the summer which extends from 1st March to the 15th June, in this season, practically speaking, nothing is planted except a small quantity of millets, and in the middle of the season from the 1st May to the 15th June all agricultural work is stopped owing to the great heat and deficiency of water: and 3rd, the flood season or “Demera” from the 15 June to the end of October; in this season the rains fall, the Nile rises and the heat is decreased, two crops of millets can be taken and cotton, sesame and earthnuts are sown.

“Manures are the same as in Egypt.

“Cotton sown in March, April and May needs so much water through the summer that its cost is prohibitive. In the really hot weather it must be irrigated every three days. High winds and rain hurt the first open pods, and the pickings are on the 20th August, 20th September and 15th October. After 22 waterings a good field will give 4¹⁄₂ cwt. per acre.

“Cotton sown in June and July has an even, regular growth. The rains and moisture in the air encourage the growth of the plant. The height of the flood permits of easy irrigation even when it is lift. The plants grow to a great size but have many bolls. The following table will show the growth of the plants.

“The yield of a good field is 5¹⁄₂ cwt. per acre. The fibre is better than that of the cotton sown in March and April.

“I consider that June and July are the best months for sowing, and that cotton sown from well-selected seed and well cultivated will prove itself a cotton of superior quality, ranking with Egyptian cottons.

“The following table gives the kinds of crops, other than cotton which can be profitably grown in the Sudan:—

“Fodder crops such as birseem and vetches (gilban) when well watered are satisfactory.

“If the land is not well tilled, manured and looked after, wheat will require 6 waterings and barley 4 waterings.

“If water can be obtained in the Sudan, the agricultural problem is very easy.”

I cannot do better than close this chapter with this thoroughly Egyptian remark of Ibrahim Effendi Fehmy.

CHAPTER V.
The Oases and the Geology of the Nile valley,
by Mr. H. J. L. Beadnell, F. G. S., F. R. G. S.

40. The Oases.

—The chief oases[6] of the Libyan desert—Dakhla, Kharga, Baharia and Farafra,—occupy extensive depressions cut down through the horizontal Eocene strata[7] to the underlying saddle of Cretaceous rocks; some of the more porous beds of the latter are water-bearing and from them, either through natural passages or through artificial borings, the water rises to the surface, often under considerable pressure. The floor level varies considerably but the cultivated lands in general lie between 70 and 115 metres above sea level.

41. Dakhla oasis.

—This, by far the most important and prosperous of the Egyptian oases, lies three days’ march west of Kharga, or about 300 kilometres due west of Armant in the Nile valley. The site is a depression lying at the foot of the great east and west Cretaceous escarpment, bounded to the south by the undulating desert of Nubian sandstone, which stretches unchanged almost to the heart of the continent. The inhabitants of Dakhla, numbering over 17,000, are distributed among 12 villages and form a practically self-supporting community. The cultivable land within the oasis (400 square kilometres) amounts to nearly 50,000 acres, of which one half is under cultivation; in addition several extensive areas of alluvium covered ground exist outside the oasis proper, notably on the Gabbari road between Dakhla and Kharga. Owing to the difficulty of drainage, salines, saltyland, marshes and pools occupy some 7,000 acres.

There are nearly 130,000 adult palm trees in Dakhla, a large export trade in dates being carried on with the Nile valley; the finest crops of wheat and barley are raised, while the fruits of the oasis, oranges, apricots, mulberries, etc., are abundant and of excellent quality.

Taxes are levied as follows:—(1) Mature date-palms are taxed 1¹⁄₂ piastres each per annum; (2) Modern wells (i.e. biyâr, made with the existing boring plant) pay 50 piastres per annum per qirat of water; (3) Ancient wells (aiyûn) pay the same, except that in some cases those used for irrigating palmgroves are exempt. There are 7¹⁄₂ trees and 1¹⁄₂ acres per inhabitant, and the total tax paid by the community is about £E. 2,500.

The water-supply of the oasis is derived from an underground bed of sandstone, 55 metres thick, underlying a dense impervious red clay 45 metres in thickness; the upper part of the latter is conspicuous throughout the oasis, underlying the alluvium and forming the base of the surrounding escarpments in many localities. Below the water-bearing sandstone lies a black clay, never yet penetrated by the boring rods; it is probable that other water-tables exist below and such would be invaluable for the irrigation of those parts of the oasis where the present supply is unsatisfactory. There seem to be no natural springs extant at the present day, the whole of the water-supply being through boreholes, both ancient and modern. The old wells, known as ain, aiyûn, appear to be mostly of early Egyptian and Roman construction, and number over 400; exactly similar wells have been sunk by boring plant during the last few decades and are called bîr, biyâr; there are over 160 of these; all are true artesian wells. At the present day the method in vogue is as follows:—a two metre square timbered shaft is sunk by hand to the base of the red clay and within this is built up a watertight wooden pipe, 35 cm. in diameter, made of ‘sunt’ (a species of thorny acacia), the surrounding space being packed with clay. Sinking is continued in the sandstone with the boring machine until a satisfactory flow of water is obtained. Many of the older wells in the oasis have become choked up, and although some have been successfully cleaned out by the inhabitants, but the process is costly and laborious and frequently fails. The work is done by divers, a small but hardy class only found in Dakhla and Farafra.

The output of wells is determined in a somewhat rough and ready manner by measuring the depth of water passing over a weir fixed in the stream. It is reckoned in qirats, one qirat being a water-section of 64 square centimetres; from some test observations in Kharga Dr. Ball deduced the average value of a qirat, as measured in that oasis, as 230 litres a minute. The total water-output in Dakhla (1096 qirats) may thus be taken as approximately representing a discharge of 132 million cubic metres per annum, and taking the cultivated lands as 25,500 acres the duty is 6,130 acres per cubic metre per second. That the water-supply could be largely increased, and the limits of cultivation greatly extended, admit of no doubt, but with the free hand accorded the natives during the last few decades a considerable amount of damage has been done throughout the oasis by the injudicious sinking of wells. Promiscuous boring is fatal, and strict and efficient control of all boring operations imperative. Considering the number of wells abandoned owing to a slight fall in the water-level having caused them to cease running at the surface, the importance of lifting appliances, in the shape of shadûfs, saqias, or windmills, is evident, but until a few years ago the oasis was destitute of such appliances; a number of saqias have recently been fixed in the village of Mushîa and have met with success, but it is not an easy matter to persuade the inhabitants to have recourse to lifting appliances of any description.

Some of the Dakhla wells are of considerable depth; Bir-el-Dinaria, the most northerly in the oasis, is 144 metres deep and its water emerges with a temperature of 39·5° C. The best wells yield 9 or 10 qirats, though before the modern boring operations the output of some was as much as 16. The terms ‘artesian’ and ‘thermal’ may fairly be applied to the Dakhla wells, and it is noteworthy that the temperatures as a whole increase from south to north. The thermal character of the springs may be considered to be due to the great depths from which the water is derived, the actual temperature at the point of exit being dependent on local conditions, such as the depth of the well and the rate at which the water finds its way to the surface. It is probable that the water-bearing table has its outcrop in the rainy regions of Darfur, although some of its water may be derived by direct infiltration from the Nile in its upper reaches.