THE NILE IN HARNESS
Within a mile or so of the red granite quarries, out of which Pompey’s
Pillar and the obelisks were taken by the ancient Egyptians, just below
the island of Philæ, with its stone temples built ages ago to the Goddess
Isis, far up the Nile valley, on the edge of Lower Nubia, I write these
notes for my American readers. I am in the heart of the desert, seven
hundred miles south of the Mediterranean Sea, at the point where the
great river drops down over the first cataract. I have come here to
describe the Aswan Dam, which the British built to harness the Nile and
thereby save Egypt from famine.
We all look upon this as the oldest of rivers, but the Nile god of to-day
has many new aspects. For ages he has been ramping and charging at his
own sweet will, but he is now being harnessed and will have to work in
the traces like an old plough mule. In the past he has been feeding his
daughter Egypt or not, as he pleased. He has sometimes stuffed her to
repletion, and at others has held back his supplies of water and mud,
causing a famine. This was the case during the seven hungry years of
Joseph’s time, and the fat years of that day were undoubtedly produced by
high Niles. Such ups and downs have occurred in Egypt from time to time
since the dawn of her history, and it is only in comparatively recent
years that man has attempted to control the old river and by a system of
dams hold back the waters and let them out over the farms as needed. To
master the Nile has cost many millions of dollars which have gone into
building the great barrages in the lower river, and more important than
all, the mighty dam away up here at Aswan.
Egypt is almost rainless and the Nile gives both land and people their
food and drink. I have already described some of the wonders of the
stream and what it does for Egypt. It rises in Lake Victoria, in Central
Africa, and drops a distance greater than the altitude of the highest
of the Alleghanies before it flows into the Mediterranean Sea. In the
upper part of its course it is known as the White Nile, and this should
be called the main stream of the river. At Khartum, thirteen hundred and
fifty miles from the Mediterranean, the Blue Nile, which rises in the
Abyssinian Mountains, comes in, while about one hundred and forty miles
farther north the Atbara, or Black Nile, which is also from Abyssinia,
joins the main stream. From the mouth of the Atbara to the sea there is
not a tributary of any kind connected with the river. It ploughs its way
through the desert valley, in which it has built up Egypt, narrowing and
widening, until a few miles below Cairo, where it divides into two great
branches and flows off into the sea.
The volume of the Nile is enormous. At flood times, a billion tons of
water go by at Aswan every day. The river then rises twenty-five feet
at Cairo, thirty-eight feet at Old Thebes, and almost fifty feet at the
first cataract, where I now am. There is so much water that no dam could
hold it, hence all of these great works had to be made so that the water
can be let in and out and allowed to pass through at will.
It is at flood time that the Nile valley gets its rich feed of Abyssinian
mud. This is brought down in part by the Blue Nile, but more abundantly
by the Atbara, or Black Nile. It is carried by the inundation all over
Egypt and by means of irrigation conducted to nearly every farm. After
the floods subside the muddy waters grow clear again. The Blue Nile and
the Black Nile become almost dry, and the white water of the main, or
Victoria Nile, is about all that Egypt has. It is this white water that
is stored up by the Aswan Dam, and it feeds the country in much the same
way as our irrigation canals do, with water only and not with a thick
mixture of water and mud as in the times of the overflow.
For thousands of years these rivers have been pouring down through this
Nile valley; but whenever the rains have been scanty in the highlands of
Abyssinia and in Central Africa the main stream has not been high enough
to reach the whole country. Most of the lands could be inundated only
once a year, and if the Nile was especially low some could have no water
at all. By the present system Egypt has water all the year round, and
enough to make it produce two or three crops every twelve months.
I have been much interested in the irrigation works of the past. The
whole of the Nile valley above Cairo is cut up into a series of basins.
For six hundred or seven hundred miles north of this point the valley
slopes very gradually and, in order to save the water, dikes have been
made across it and embankments run parallel with the river, turning the
whole country into a series of basin-like terraces, each containing from
five thousand to fifteen thousand acres. These basins, which are often
subdivided, are so connected that the water flows from one to the other
until it finally passes out of the lower basin back into the Nile. When
the floods come, the lowest basins are filled first and then those higher
up, until at last all have become great ponds and Egypt is one vast
inland sea cut up by the embankments and islands upon which the villages
stand.
There are many such systems of basins in Upper Egypt, some large and
some small. There are also basins higher up and closer to the river
which are filled with _sakiebs_ or _shadoofs_. When I tell you that the
fall of this valley from here to Cairo is only seven inches to the mile
you will see how carefully these basins must be graduated in order to
take advantage of the flow of the river. They have to be so constructed
that the water can be drained off as rapidly as it is let on. As I have
already said, the Abyssinian mud contains a great quantity of salts,
and it is just as bad to have too much of it as too little. If the land
is over-watered the salts dissolve from the soil, the over-soaked land
becomes wormy, and the crops are often sown too late. The red water, or
that containing the silt, is allowed to stand just about forty days.
During this time it drops a great deal of sediment and furnishes enough
moisture for the crops.
But the Aswan Dam has so regulated the river flow that the Egyptian
farmer is far less at the mercy of low Niles or high Niles than in the
past. The dam is one of the wonders of modern Egypt. It is in full sight
of me as I sit here on the left bank of the Nile, with the desert at my
back. It looks like a great stone viaduct crossing the rocky bed of the
river, joining the stony hills which wall the Nile on both sides, and
holding back a portion of its mighty waters. It is a huge granite barrier
a mile and a quarter long. There is now a roadway guarded by walls on its
top, and there is a miniature railway, the cars of which are pushed by
men from one end to the other. The dam serves as a bridge as well, and
donkeys, camels, and men are allowed to pass over it from bank to bank. I
crossed on the car at a cost of twenty-five cents, my motive power being
two Arab boys who trotted behind.
As I came over, I stopped from time to time to examine the construction.
The dam is made of big blocks of red granite as fine as that of any
tombstone in the United States. They are beautifully cut, and fitted as
closely as the walls of a palace. On the upper side or south face the
wall is perpendicular, forming a straight up-and-down barrier against the
waters of the Nile. I climbed down a ladder on that side at one place
almost to the river, and could see that the blocks are fitted so closely
that the cement does not show. The masonry seems almost one solid stone
throughout, with the exception of where the great sluices are cut, to
allow the river to flow through at the times of the flood, and as the
floods subside to shut back the waters to form the reservoir for the dry
season.
There are one hundred and eighty of these sluice gates in the dam, each
of which has steel doors that can be raised or lowered to allow the
whole river to flow through or to hold back as much or as little as the
engineers will. The dam is thus a great stone wall pierced by these gates.
The Nile never flows over the top of the dam, but always through the
gates and the canal at one side. When the gates are closed during the
dry season, enough water is held back by this structure of steel and
granite to form a lake over one hundred miles long, and this is let
out as needed to supplement the ordinary flow of the river and give the
crops plenty of water all summer through. There is water enough in the
reservoir to give all the families of the United States all they could
use for four or five months, and enough to supply Great Britain and
Ireland the entire year.
The weight of this water is stupendous and its force inconceivable.
Nevertheless, during the floods fully as much runs through the dam
every day as the whole supply kept back during the dry season; and the
structure had to be made so that it would retain this huge lake and at
flood time let a lake equal to it pass through.
Talk about the Pyramids! The Aswan Dam is far more wonderful than they
are. The Pyramid of Cheops required one hundred thousand men and over
twenty years in its building. The Aswan Dam was constructed by about
eleven thousand men in four years. The Pyramid of Cheops was made by
forced labour and impoverished the people. The Aswan Dam cost about
twelve million dollars and the men who worked upon it were better
paid than any others who had ever laboured in the valley of the Nile.
Moreover, the dam has meant prosperity for Egypt. It has added to it more
than one million five hundred thousand acres of tillable land and has
increased the value of its crops by over thirteen million dollars per
annum. It has more than paid for its cost every year. Since it has been
built the yearly tax revenues have gained by two million dollars, and the
lands owned by the government have become worth five million dollars more.
The dam is also more wonderful than the Pyramids in its construction. Old
Cheops is built on the edge of the desert on a solid stone platform,
and is little more than the piling of one stone upon another. For the
Aswan Dam a trench a hundred feet wide and a hundred feet deep had to be
excavated in the granite rock. This was bedded with concreted rubble to
form the substructure upon which the masonry was raised. The dam itself
contains more than a million tons of granite and about fifteen thousand
tons of steel, and the calculations of the engineers are so exact that
they know just how much every ounce of stone and steel will hold back.
I have had some talks here with the engineer-in-chief of the dam, and am
surprised at the wonderful intelligence bureau that has been created in
connection with the control of the Nile. Its officials know the exact
weight of the river at every hour of the day. They have telegraphic
reports on what the Nile is doing in Abyssinia, in Central Africa, and
in the Sudan. They have dispatches as to every great rain, and they know
to a ton just how fast Lower Egypt is using the water, so they can tell
how much or how little to let out for the farms. They even estimate the
force of the sun on the water and know how much it drinks up every day.
When the reservoir is full Old Sol takes a million and a half tons from
it every twenty-four hours. They know what the evaporation is, not only
at Aswan, but all along the great stream and throughout its swamps to its
source in Lake Victoria.
[Illustration: The gift of the Nile is not had without work. _Fellaheen_
too poor to own camels or bullocks lift the river water from level to
level and pour it into the irrigation ditches.]
[Illustration: The _fellaheen_ live in villages and go out to work on the
farms. The average mud hut seldom contains more than one or two rooms and
is at the mercy of thick clouds of dust from the road.]
I am also amazed at the strength and delicacy of the machinery of this
remarkable structure. The great sluice gates are each as high as a
two-story house, and so wide that you could drive a hay wagon through
them without touching the walls. They are cut right through the granite
dam and are closed or opened by steel doors, which slide up and down
inside the wall on rollers. Upon the top of the dam there are machines
for moving these gates, so made that a child could operate them. They are
equipped to be operated by electricity, but they are now worked by hand,
and this mighty force, so tremendous that two billion horses would be
required to move it, is now controlled at will by the muscular power of a
single man.
This thought was impressive as I sat below the dam, where the eight
central sluices pressed by the millions of tons of water lying behind
them poured forth their mighty flood. I had climbed down the steps at the
north side of the centre of the dam to make a photograph of the streams
flowing through. They come forth with a rush like that of Niagara and
go foaming over the rocks with a force that might generate thousands of
horsepower. The noise is like thunder and the torrents fairly shake the
earth. Each is about fifteen feet in height and yellow with mud. There
were eight such streams of golden foam at my right, and farther over I
could see the spray from others all dashing through the dam until they
met in a yellow frothing mass several hundred feet below me and rolled
onward down the rocks to Egypt. They flow out with such a force that they
tear up the rocky bed of the Nile, lifting stones weighing many tons and
carrying them some distance down the river. They have done so much damage
of this nature that a cement foundation has now been made below the dam
itself in order to prevent the gouging out of the bed which would mean
the undermining of the main structure.
But the thirsty land and its teeming millions forever clamour for more
water. Even this great Aswan Dam has not nearly solved the irrigation
problem of Egypt. There are always too many would-be farmers for the
watered area. At the present rate of growth, it is estimated, the
population will have increased by the middle of the century to twenty
millions of people, practically all of them dependent on agriculture,
and so on this one river system. The government has yet more ambitious
schemes for hoarding and meting out its precious waters.
At Wady Halfa, about two hundred miles up the river from Aswan, begins
the Sudan, which extends for thousands of miles southward. In controlling
this vast territory, Great Britain has hold also of the upper reaches of
the Nile from the south boundary of Egypt proper into the Great Lakes of
Central Africa where the river has its source. The irrigation works, new
dams, and reservoirs planned or building on the Upper Nile are intended
to increase the arable lands not only in the Sudan but in Egypt as well.
The projects which the British have for the improvement of the Nile will
rank as the most daring of the engineering plans of the century. To carry
them out will cost as much as the Suez Canal, but they will build up
fifteen hundred or two thousand miles south of the Mediterranean Sea,
several other Egypts twice or thrice as rich as the lower Nile valley,
each supporting its millions of people.
The projects include schemes for the regulation of the Great Lakes on the
highlands of Central Africa, to make them serve as reservoirs for the
Nile. They include, also, plans for the embankment of the tributaries of
the White Nile flowing through the great swamps on the northern slope
of the Congo watershed, and the digging of over two hundred miles of
new channel, whereby the main stream of the White Nile will be greatly
shortened and its bed fitted to carrying the enormous volume of its
waters down to Khartum. Another scheme contemplates the erection of a dam
at Lake Tsana, on the highlands of Abyssinia, which will make that lake
a reservoir for the Blue Nile and enable it to water the fertile plain
which lies between the Blue and White Niles, ending at Khartum.
The great trouble now is that a large part of the waters of the Nile go
to waste, particularly in the swamps of the Sudd region. These mighty
swamps lie on the northern slope of the Congo watershed and are fed by
the branches of the White Nile known as the Bahr el Jebel, the Bahr el
Ghazal, and the Bahr el Zaraf. They begin where the River Sobat flows
into the Nile and form an irregular triangle, the base running from that
point two hundred miles westward, with the southern apex at Bor, which
is two or three hundred miles farther south. They lie on the bed of what
in prehistoric times was a great lake, and are composed of masses of
reeds, papyrus, and other swamp grasses, so interlaced that they soak up
the water like a huge sponge. Imagine a sponge as big as the State of
Indiana, from two to six feet in thickness, and so situated that it is
always filled by the waters of the Nile and you will have some idea of
this region. This sponge is near the Equator where the tropical sun beats
down upon it, so that steam is always rising. It sucks up the waters of
the Nile and gives them out into the air. The evaporation in the Sudd
and along the courses of the Nile is so great that an amount equal to
half the capacity of the Aswan reservoir is lost every day. In the summer
fully fifty per cent. of the water supplied by the Great Lakes never gets
into the main stream of the Nile. The water of this swamp is nowhere much
above a man’s head, and in most places, except where the main stream
flows through, it is only waist-deep. The evaporation increases at the
time of the flood, when more land is covered, so that no matter how much
water flows into the swamp, only about the same amount flows out.
The vast masses of floating weeds break up and burst into the channels,
and when an obstruction is encountered they pile up on one another just
as ice does. In the hot, dry season, when the stems of the papyrus are
ten or fifteen feet high, the natives start fires which sweep the region
from end to end, destroying all other vegetation. The ashes and burnt
stems add to the floating mass, which after a time becomes five or six
feet in thickness and almost like peat.
In clearing this Sudd and reopening the channels, the first step is to
cut down the vegetation. The sponge-like mass is then cut with long saws
into blocks, much as ice is harvested on our ponds. The blocks are pulled
out into the current by steel cables attached to the engines on the
steamers and float down the stream. An immense deal of this kind of work
is going on all along the Upper Nile, for it is only in this way that
navigation is kept open.
I have met some of the surveyors who are breaking a way through the Sudd.
They describe it as a vast sheet of brilliant green made up of papyrus,
feathery reeds, and sword grass. These rise from five to fifteen feet
above the water and are broken here and there by patches of ambatch trees
and by channels, pools, and lagoons. The greater part of the region has
no human inhabitants, especially that along the Bahr el Ghazal.
Big game is to be seen only to the south of the swamp area. There the
land is a little higher, and elephants, giraffes, and buffaloes inhabit
the edges of the swamps. In the heart of it, in fact, in all parts of it,
there are vast numbers of hippopotami, and there are all sorts of swamp
birds everywhere. From the reeds and the mud banks clouds of wild cranes,
geese, storks, herons, pelicans, and ducks of every description rise up
as the boats approach, and there are insects by millions—mosquitoes,
moths, spiders, and flies. There are other insects that carry fevers, and
the tsetse fly, which causes the sleeping sickness.
When all the Upper Nile plans and projects have been put through, the
whole river will indeed be a magically powerful, yet tamed and harnessed,
domestic animal at the command of the farmers of a greater Egypt and a
greater Sudan.