king’s reign, and he reigned 42 years and some months. The next
following dates are, the years 9, 14, 15, 20, 22, 23, 24, 30, 32,
37, 40, 41, and 43; and include, therefore, under this king, a
period of 37 years. Of the remaining dates, that only of the 4th
year of his two successors is available; all the others, which
are on the west or left bank of the river, have been moved from
their original place by the rapid floods which have overthrown
and carried forward vast masses of rock. One single mark only,
that of the 9th year of Amenemha, has been preserved in its
original place on one of the building stones, but somewhat below
the principal rapid.
“We have now to consider the relation which these—the most
ancient of all existing marks of the risings of the Nile—bear to
the levels of the river in our own time. We have here presented
to us the remarkable facts, that the highest of the records now
legible, viz., that of the 30th year of the reign of Amenemha,
according to exact measurements which I made, is 8·17 metres (26
feet 8 inches) higher than the highest level to which the Nile
rises in years of the greatest floods; and further, that the
lowest mark, which is on the east bank, and indicated the 15th
year of the same king, is still 4·14 metres (13 feet 6½ inches):
and the single mark on the west bank, indicating the 9th year, is
2·77 metres (9 feet) above the same highest level.
“The mean rise of the river, recorded by the marks on the east
bank, during the reign of Mœris, is 19·14 metres (62 feet 6
inches) above the lowest level of the water in the present day,
which, according to the statements of the most experienced
boatmen, does not change from year to year, and therefore
represents the actual level of the Nile, independently of its
increase by the falls of rain, in the mountains in which its
sources are situated. The mean rise above the lowest level,
at the present time, is 11·84 metres (38 feet 8 inches); and,
therefore, in the time of Mœris, or about 2200 years before
Christ, the mean height of the river, at the cataract or rapid of
Semne, during the inundation, was 7·30 metres (23 feet 10 inches)
above the mean level in the present day.”
Such are the facts recorded by Dr. Lepsius; and then follow, in the same
letter, his views as to the cause of the remarkable lowering of the level
of the river.
“There is certainly no reason for believing,” he says, “that
there has been any diminution in the general volume of water
coming from the south. The great change in the level can,
therefore, only be accounted for by some changes in the land,
and these must also have altered the whole nature of the Nile
Valley. There seems to be but one cause for the very considerable
lowering of the Nile; namely, the washing out and excavations of
the catacombs (_Auswaschen und Aushölen der Katakomben_[379]);
and this is quite possible from the nature of the rocks
themselves, which, it is true, are of a quality that could not
well be rent asunder, and carried away by the mere force of the
water, but might be acted upon directly by the rising of the
water-level, and the consequent effects of the sun and air on
the places left dry, causing cracks, into which earth and sand
would penetrate, which would then give rise to still greater
rents, until, at last, the rocks would of themselves fall in, by
having been hollowed out, a process that would be hastened in
those parts of the hills where softer and earthy beds existed,
and which would be more easily washed away. But that, in
historical times, within a period of about 4000 years, so great
an alteration should take place in the hardest rocks, is a fact
of the most remarkable kind—one which may afford ground for many
other important considerations.
“The elevation of the water-level at Semne must necessarily have
affected all the lands above; and, it is to be presumed, that
the level of the province of Dongola was at one time higher, as
Semne cannot be the only place in the long tract of cliffs where
the bed of rock has been hollowed out. It is to be conceived,
therefore, that not only the widely-extended tracts in Dongola,
but those of all the higher country in Meröe, and as far up
as Fasogle, which, in the present day, are dry and barren on
both sides of the river, and are with difficulty irrigated
by artificial contrivances, must then have presented a very
different aspect, when the Nile overflowed them, and yearly
deposited its fertile mud to the limits of the sandy desert.
“Lower Nubia also, between Wadi Halfa and Assuan, is now arid
almost throughout its whole extent. The present land of the
valley, which is only partly irrigated by water-wheels, is, on
an average, from 6 to 12 feet higher than the level to which the
Nile now rises; and although the rise at Semne might have no
immediate influence upon it, yet what has occurred there makes
it more than probable that at Assuan there was formerly a very
different level of the river, and that the cataracts there, even
in the historical period, have been considerably worn down. The
continued impoverishment of Nubia is a proof of this. I have no
manner of doubt that the land in this lower part of the valley,
which, as already stated, is at present about 10 feet above the
highest rise of the Nile, was inundated by it within historical
time. Many marks are also met with here, that leave no doubt
regarding the condition of the Nile Valley antecedent to history,
when the river must have risen much higher; for it has left an
alluvial soil in almost all the considerable bays, at an average
height of 10 metres (32 feet 9 inches) above the present mean
rise of the river. That alluvial soil, since that period, has
doubtless been considerably diminished in extent by the action
of rain. On the 17th of August Hr. Erbkam and I measured the
nearest alluvial hillock in the neighbourhood of Korusko, and
found it 6·91 metres (22 feet 7 inches) above the general level
of the valley, and 10·26 metres (33 feet 7 inches) above the
present mean rise of the river. That rise, which at Semne, on
account of the greater confinement of the stream between the
rocks, varies as much as 2·40 metres (7 feet 10 inches) in
different years, varies at Korusko less than 1 metre (3 feet 3
inches).
“Near Abusimbel, on the west bank, I found the ground of
the temple 6·50 metres (21 feet 2 inches) above the highest
water-level. This temple, it is well known, was built under
Rameses the Great, between 1388 and 1322 years before Christ.
Near Ibrîm there are, on the east bank, four grottoes excavated
in the vertical rock that bounds the river, which belong partly
to the 18th and partly to the 19th Dynasties; the last, under
Rameses the Great, is also the lowest, and only 2·50 metres (8
feet 1 inch) above the highest inundation; the next in height is
2·70 metres (8 feet 9½ inches) above the former, and was made 250
years earlier, under Tutmes III. Although I only measured the
present level of the valley near Korusko, nevertheless it appears
to me that, during the whole of the new kingdom, that is, from
about 1700 years before Christ to this time, the Nile has not
reached to the full height of the low land of the valley.
“It is, however, conceivable that, at the time when the present
low land of the Nubian Valley was formed, the cataracts at Assuan
were in a totally different state; one that would, in some
degree, justify the overcharged descriptions of the ancients,
according to whom they made so great a noise that the dwellers
near them became deaf. The damming up of the inundation at Assuan
could have no material influence on Egypt, any more than that at
Semne, or the land from thence to Assuan.”
It appears, therefore, from the above statements, that at the time
mentioned, the Nile, during the inundations, stood 26 feet 8 inches
higher than the highest level to which it now rises in years of the
greatest floods; and that, to account for this, Professor Lepsius
conceives that, between the time of Mœris and the present day, the bed of
the Nile, from a considerable distance above Semne to Assuan, must have
been worn down to that extent. In the index to the volume of the Berlin
Monatsbericht, in which the letters of Professor Lepsius are inserted,
there is the following line:—
“NIL, _senkung seines Bettes um 25 Fuss seit 4000 Jahren_.”
“_Nile_, sinking of its bed about 25 feet (Paris) within the last
4000 years.”
Rivers are, undoubtedly, among the most active agents of change that are
operating on the earth’s surface; the solid matter which renders their
waters turbid, and which they unceasingly carry to the sea, afford
indisputable proof of this agency. But the power of rivers to abrade and
wear down the rocks over which they flow, and to form and deepen their
own bed, depends upon a variety of circumstances not always taken into
account; and although the great extent of that power, in both respects,
is shown in the case of many rivers, to conclude, as some have done,
from these instances, that all rivers have excavated the channels in
which they flow, is a generalisation that cannot be safely assented
to. The excavation of the bed of a river is one of those problems in
geological dynamics which can only be rightly solved by each particular
case being subjected to the rigorous examination of the mathematician
and the physicist. The solid matter which rivers carry forward is in
part only the produce of their own abrading power; and the amount of it
must be proportional to that power, which is mainly dependent on their
velocity; they are the recipients of the waste of the adjoining lands by
other combined agencies, and the carriers of it to the lower districts
and to the sea. They often afford the strongest evidence of the vast
lapse of time that must be included between the beginning and close of
a geological period; and, when they flow through countries whose remote
political history is known to us, they supply a scale by which we may
measure and estimate that lapse of time. This is especially so in the
case of the Nile.
When so startling an hypothesis as that now referred to, viz., that the
entire bed of so vast a river as the Nile, for more than 250 miles,
from Semne to Assuan, has been excavated, within historical time, to a
depth of 27 feet, is made by a person whose name carries so much weight
in one department of philosophical inquiry, the statement involves
such important geological considerations, that it becomes the duty of
the geologist to examine, and thoroughly test, the soundness of the
explanation, in order that the authority of Professor Lepsius for the
accuracy of the facts observed, may not be too readily admitted as
conclusive for the correctness of his theory of the cause to which they
owe their existence. That there has been such an undoubting admission,
appears from the following passage in the work of one of the latest
writers on Nubia:
“The translation of the name of this town (Aswán) is ‘the
opening;’ and a great opening this once was, before the Nile had
changed its character in Ethiopia, and when the more ancient
races made this rock (at the first cataract) their watch-tower
on the frontier between Egypt and the south. That the Nile has
changed its character, south of the first cataract, has been made
clear by some recent examinations of the shores and monuments
of Nubia. Dr. Lepsius has discovered water-marks so high on the
rocks and edifices, and so placed as to compel the conviction
that the bed of the Nile has sunk extraordinarily by some great
natural process, either of convulsion or wear. The apparent
exaggerations of some old writers about the cataracts at Syene
may thus be in some measure accounted for. If there really was
once a cataract here, instead of the rapids at the present day,
there is some excuse for the reports given from hearsay by Cicero
and Seneca. Cicero says, that ‘the river throws itself headlong
from the loftiest mountains, so that those who live nearest are
deprived of the sense of hearing, from the greatness of the
noise.’ Seneca’s account is: ‘When some people were stationed
there by the Persians, their ears were so stunned with the
constant roar, that it was found necessary to remove them to a
more quiet place[380].’”
The learned author of an article on Egyptian Chronology and History in
the “Prospective Review” for May, 1850, in referring to the contributions
of Professor Lepsius to Egyptian history, says: “He has discovered
undescribed pyramids, equal in number to those known before; has traced
the Labyrinth, and ascertained its founder. _He has detected inscriptions
on the banks of the Nile, which show that its bed has subsided many feet
in historic times._” _9th June, 1850._
In the assumption of an excavation of the bed of the river, we have no
small amount of wear to deal with, for the distance from Semne to Assuan,
following the course of the river, is not less than 250 miles; and if, as
Professor Lepsius supposes, the excavation extended to Meröe, we have a
distance, between that place and Assuan, of not less than 600 miles.
Although these records of a former high level of the Nile at Semne had
not been noticed by any traveller prior to Professor Lepsius, we may
rest fully assured of the accuracy of his statements, from the habitual
care and diligence, and the established character for fidelity, of the
observer. The silence of other travellers may be readily accounted for by
this, that none of them appear to have remained more than a very short
time at this spot—not even the diligent Russegger—whereas we have seen
that Professor Lepsius passed twelve days in the examination of this
gorge in the Nile Valley.
The theory of a lowering of the bed of the river by wearing, involves
two main considerations, viz., the power of the stream, and the degree
of hardness of the rocks acted upon. The power depends upon the volume
and velocity of the river—the velocity on its depth, and the degree of
inclination of the bed: the hardness of the rocks we can form a tolerable
estimate of when we know their nature. To judge, therefore, of the
probability of the hypothesis of Professor Lepsius, we must inquire into
the physical and geological features of the Nile Valley, in Nubia.
In the observations I have now to offer, my information has been derived
of course entirely from the works of other travellers, particularly those
of Burckhardt, Rüppell, and Russegger[381], and especially the latter,
who travelled in Nubia in 1837; for he not only enters far more into
the details of the natural history of the country, but he is the only
traveller in Nubia who appears, from previous acquirements, to have been
competent to describe its natural history with any degree of accuracy—I
refer more particularly to the physical and geological features of
the country. Besides full descriptions in his volumes, he has given a
geological map of Nubia, and also several sections, or what may more
properly be called _vertical sketches_—a term that would, perhaps, be
a more appropriate designation for all sections that are not drawn to
a true scale, or at least when the proportion of height to horizontal
distance is not stated.
_The Physical Geography of Lower Nubia[382]._
Russegger informs us[383], that he believes he was the first traveller
who had succeeded in making a series of barometrical measurements along
the Nile Valley, from the Mediterranean to Sennaar and Kordofan, and
thence to the 10th degree of north latitude. He gives the following
altitudes, above the sea:
Paris Feet. English Feet.
The upper part of the Cataract of Assuan 342 = 364·37
Korusko, on the right bank of the Nile, in Nubia 450 = 479·43
Wadi Halfa 490 = 522·00
New Dongola 757 = 806·52
Abu Hammed 963 = 1026·00
I shall now give the length of the Nile along its course from Abu
Hammed to the island of Philæ, at the head of the cataract of Assuan. I
employ for this purpose the map in the atlas which accompanies the work
of Russegger, which bears the date of 1846, and which, doubtless, was
constructed on the best authorities. He mentions a map of General von
Prokesch with great praise[384]. It flows:
German M. English M.
From NE. to SW., from Abu Hammed to Meröe, about 31 = 150
It makes a curve between Meröe and Old Dongola,
of about 16 = 77
It flows between Old and New Dongola, from SE.
to NW., about 16 = 77
Then, with some short windings, nearly due north
to the island of Sais, for about 30 = 145
And from Sais to the island of Philæ, from SW.
to NE., about 68 = 327
--- ---
Making the whole length of the course, from Abu
Hammed to Philæ, about 161 = 776
Ascending the river, we have, between Philæ and Korusko, a distance of
24 German, or 115½ English miles, and without any rapid, except one near
Kalabsche. Korusko being 115 feet above the head of the cataract of
Assuan, at Philæ, we have an average fall of the river between these two
places of a foot in a mile.
Between Korusko and Wadi Halfa there is no rapid. The distance being 20
German, or 96⅓ English miles, and the difference of altitude being 42½
feet, we have an average fall throughout that part of the river’s course
of not more than 5·3 inches in a mile.
This very inconsiderable fall need not surprise us; for the average
fall of the Nile in Lower Egypt, at the lowest water, is little more
than one-third of that now stated. At the time of the highest water the
surface of the Nile, at Boulak, near Cairo—that is, about 116 miles in a
direct line from the coast—is only 43·437 English feet above the level of
the Mediterranean, and at the time of the lowest water, only 17·33 feet.
Thus, in the first case, there is an average fall of about 5·00 inches;
in the second, of not more than 1·80 inches in a mile[385].
Between Wadi Halfa and Dale, a distance of about 94 miles, six cataracts,
or schellals, as they are called in the language of the country, are
marked in Russegger’s map. And here, it may be as well to notice, that
there are no cataracts, in the ordinary sense of the term, on the Nile;
no fall of the river over a precipice; all the so-called cataracts
are rapids, where the river rushes through rocks in its bed; the
rapids varying in their length and degrees of inclination. We have no
measurements of their lengths or of their falls, except as regards the
first and second cataracts. The former, according to Russegger, has a
fall of about 85 English feet in a distance of about 8 miles; and he
describes the latter as extending from 5 to 6 _stunden_; that is, from 12
to 14½ miles, but he does not give the height. Speaking of the schellals
above Semne, Russegger says, that all may be passed in boats without
difficulty for about six weeks, or two months in the year. This is the
case also at the cataract or rapid of Assuan. But between Wadi Halfa and
Dale, with some inconsiderable spaces of free navigable water, in the
ordinary state of the river, there is an almost uninterrupted series of
rapids. We have no measurement of the height of Dale above Wadi Halfa,
near to which the second great cataract of the Nile occurs; but this is
the part of the river’s course where the fall is greatest, and from Semne
to Dale there are about 45 miles of this more rapid fall.
From Dale to New Dongola, a distance of 35 German, or about 168 English
miles, only three rapids are marked on Russegger’s map—the highest being
at Hannek, about 26 English miles below New Dongola. New Dongola being
806 English feet above the sea, and the distance from that place to the
rapid of Hannek being 26 miles only, we may with probability estimate
the surface of the river at the rapid of Hannek at 780 feet above the
sea. Now, Wadi Halfa being 522 feet, we have a difference of height,
between these two last-named places, of 258 feet; and the length of the
river’s course between them being 236 miles, we have an average fall
of 13·12 inches in a mile; that is, in the part of the river’s course
where nine rapids occur, in the provinces of Batn-el-Hadjar, Sukkôt, and
Dar-el-Mahass, where the river flows over granite and other plutonic
rocks; gneiss, mica-schist, and other hard rocks, which Russegger
considers to be metamorphic. But between Semne and the head of the
second cataract at Wadi Halfa, there is not a continuous rapid stream;
for Hoskins says, that about two miles above that cataract, the river
has a width of a third of a mile, and, when he passed it, the water was
scarcely ruffled[386].
From the rapid of Hannek to Abu Hammed the distance is 329 English miles,
and the difference of altitude is 246 English feet. We have thus an
average fall in that distance of 9·00 inches in a mile.
Thus, in the 776 miles between Abu Hammed and Philæ, we have an average
fall of the Nile
Of 9·00 inches in a mile, for a distance of 329 miles.
Of 13·12 ” ” 236 ”
Of 5·30 ” ” 96 ”
Of 12·00 ” ” 115 ”
_Of the Breadth, Depth, and Velocity of the Nile, in Nubia._
Our information is very scanty respecting the breadth and depth of the
river, either at the time of lowest water or during the inundations.
About two miles above Philæ, it is stated by Jomard[387] to be 3000
metres, or nearly two English miles wide. At the second cataract, or
rapid of Wadi Halfa, it spreads over a rocky bed of nearly two miles and
a quarter in width (2000 klafter)[388], but contracts above the rapid to
a third of a mile. Russegger also states, that the Nile, near Boulak,
in Lower Egypt, is 2000 toises, nearly two-and-a-half English miles in
breadth, and yet that it is considerably wider in some parts of Southern
Nubia; but Burckhardt says that the bed of the Nile in Nubia is, in
general, much narrower than in any part of Egypt. Near Kalabsche, about
30 miles above Philæ, the river runs through a gorge not more than 300
paces wide, and its bed is full of granite blocks. It shortly afterwards
again widens for some distance; but near Sialla, 78 miles above Philæ,
it is contracted by the sandstone hills on both sides coming so near
each other, that the river’s bed is again not more than from 250 to 300
paces wide. It is about 600 yards broad about two miles above the second
cataract near Wadi Halfa, but is again very much contracted in the rocky
region of Batn-el-Hadjar. At Aulike it is only 200 paces broad[389].
I have not met with any measurements of the depth of the river in any
part of its course in Nubia; but Hoskins describes it as being so
shallow at the island of Sais, 327 miles above Philæ, on the 9th of June,
which would be before the commencement of the inundation, as only to
reach the knees of the camels[390]. Near Derr, about 86 miles below the
Cataract of Wadi Halfa, Norden, in January, found the river so shallow
that loaded camels waded through it, and his boat frequently struck the
ground. In May, Burckhardt found the river fordable at Kostamne, 53 miles
above Philæ; and Parthey states, that between Philæ and the island of
Bageh, to the west of it, the river is so shallow before the commencement
of the inundation, that it may be waded through[391]. Burckhardt says,
that from March to June the Nile-water, in Nubia, is quite limpid[392].
Miss Martineau, who visited Nubia in December and January, speaking of
the river above Philæ, says, that it “was divided into streamlets and
ponds by the black islets. Where it was overshadowed it was dark-grey or
deep blue, but when the light caught it rushing between a wooded island
and the shore, it was of the clearest green[393].” At the second cataract
she describes the river as “dashing and driving among its thousand
islets, and then gathering its thousand currents into one, proceeds
calmly in its course[394].”
Although we have no accurate measurements of the velocity of the Nile in
Nubia, we may arrive at an approximate estimate of it by comparing its
fall with that of a river well known to us.
I have stated the fall of the Nile in different parts of its course to
be 5·30, 9·00, 12·00, and 13·12 inches in a mile. The fall of the Thames
from Wallingford to Teddington Lock, where the influence of the tide
ends, is as follows:
+-----------------------------------+---------+----------+----------+
| | Length | | Fall in |
| | of | Fall. | Inches |
| | Course. | | per Mile.|
| +---------+----------+----------+
| |Miles. F.| Feet. in.| |
| | | | |
|From Wallingford to Reading Bridge | 18·0 | 24·1 | 15·72 |
|From Reading to Henley Bridge | 9·0 | 19·3 | 25·68 |
|From Henley to Marlow Bridge | 9·0 | 12·2 | 16·20 |
|From Marlow to Maidenhead Bridge | 8·0 | 15·1 | 22·32 |
|From Maidenhead to Windsor Bridge | 7·0 | 13·6 | 23·16 |
|From Windsor to Staines Bridge | 8·0 | 15·8 | 23·52 |
|From Staines to Chertsey Bridge | 4·6 | 6·6 | 17·28 |
|From Chertsey to Teddington Lock | 13·6 | 19·8 | 17·40 |
| +---------+----------+----------+
| | 77·4 | 125·11 | |
+-----------------------------------+---------+----------+----------+