registered by a mark, indicating the year of the king's reign, cut
in the granite, either on one of the blocks forming the foundation
of the fortress, or on the cliff, and particularly on the east or
right bank, as best adapted for the purpose. Of these markings
eighteen still remain, thirteen of them having been made in the
reign of Moeris, and five in the time of his two next successors.
These last kings discontinued the observations; for, in the
meantime, the irruption of the Asiatic pastoral tribes into Lower
Egypt took place, and wellnigh brought the whole kingdom to ruin.
The record is almost always in the same terms, short and simple:
_Ra en Hapi em renpe_ ... mouth or gate of the Nile in the
year.... And then follows the year of the reign, and the name of
the king. It is written in a horizontal row of hieroglyphics,
included within two lines--the upper line indicating the
particular height of the water, as is often specially stated--
[Illustration: sketch of hieroglyphics]
"The earliest date preserved is that of the sixth year of the
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.[53]
Footnote 53: See Plate I.
"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 Moeris, 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 Moeris, 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
(_Answaschen und Aushölen der Katakomben_); 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 Meroë, 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 Haifa 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
Ibrim 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 Moesis 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 shewn 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 generalization
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 of 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.'"[54]
Footnote 54: Miss Martineau's Eastern Life, vol. i., p. 99.
_Note._--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
Meroë, 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,[55] 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.
Footnote 55: Reisen in Europa Asien und Afrika, in der Jahren
1835, bis 1841.--Stuttgart 1841-1846.
_The Physical Geography of Lower Nubia._[56]
Footnote 56: With reference to the object of this paper.
Russegger informs us,[57] 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
Footnote 57: Reisen, Bd. ii., 545.
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.[58] It flows:--
German M. English M.
From NE. to SW., from Abu Hammed to
Meroë, about 31 = 150
It makes a curve between Meroë 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
Footnote 58: "Über den Stromlauf und das zunächst liegende
Uferland des Nils, von der zweiten Katarakte bis Assuan, besitzen
wir eine vortreffliche Karte namlich:" "Land zwischen der kleinen
und grossen Katarakten des Nil. Astronomisch bestimmt und
aufgenommen in J. 1827, durch v. Prokesch. Nil Grundrisse der
Monumente. Wien, 1831."--Reisen Bd. ii., Thl. iii. 86.
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 96 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.[59]
Footnote 59: Russegger, Reisen, Bd. i., 258.
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, Sukkot, 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.[60]
Footnote 60: Travels in Ethiopia, p. 272.
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[61] 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),[62] 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.[63]
Footnote 61: Description de l'Égypte.--Separate Memoir entitled,
"Description de Syène et des Cataractes."
Footnote 62: Russegger, Bd. ii., 3 Thl. 85.
Footnote 63: Russegger, Bd. ii., 3 Thl. 76.