Chapter II: Part 2

While bearing witness to the good understanding that I have observed to exist between them, and the identity of their convictions, as to the possibility of the communication between the Red Sea and the Mediterranean, by a Canal accessible to large vessels, I beg them, in case the opinion of either, upon any question whatever, should not be entertained by the other, to state the difference of their views, and to assign the reasons thereof.

Finally, the precursory scheme, accompanied by an explanatory map, is to be finished as quickly as possible.

(Signed) FERD. DE LESSEPS.

APPENDIX.

No. IV.

PRECURSORY SCHEME OF MM. LINANT _BEY_ AND MOUGEL _BEY_, ENGINEERS TO THE VICEROY OF EGYPT.

EXTRACT FROM THE MEMORIAL OF MM. LINANT _BEY_ AND MOUGEL _BEY_, ENGINEERS TO THE VICEROY OF EGYPT,[4]

By way of Precursory Scheme for cutting through the Isthmus of Suez, by a direct Maritime Canal from Pelusium to Suez.

The enlightened Prince who now governs Egypt, Mohammed Saïd Pacha, wishing to withdraw the question of cutting through the Isthmus of Suez from the uncertainties of theory, and to bring it into practical reality, has granted a firman by which he concedes to the Universal Company formed by the capitalists of all countries, who are freely willing to take part in the undertaking, the construction and working of a Maritime Canal between the Red Sea and the Mediterranean, with an additional Canal for communication and irrigation, derived from the Nile.

Dictating himself the terms of the Firman of Concession, Prince Mohammed Saïd has required that the undertaking shall be complete, and that an attentive examination of the localities be made, in order to profit by all the advantages offered by nature. He has recommended that the shortest track be followed, the least expensive, and that which will admit of the largest ships. His early studies and his experience in nautical art, have perfectly prepared him for the comprehension of all the bearings of the scientific question. He has indicated Pelusium and Suez, as the extreme points of the cutting to be made in that narrow tract of land, which presents a longitudinal depression across the Isthmus, of thirty leagues, and which is formed by the meeting of the two plains descending with a gradual slope, the one from Egypt, the other from the frontier hills of Asia. He considers that nature has herself traced out the communication between the two Seas, in the line of this depression.

Towards Lake Timsah, situated at an equal distance from Suez and Pelusium, another not less remarkable furrow meets the longitudinal depression at right angles; it is that of the _Wady Tomilat_ (the fruitful land of Goshen of Scripture). This furrow still receives, for a considerable length, the overflowings of the Nile, and also appears to form the natural track of a canal of communication, commencing at the river and proceeding to connect itself in the central part of the Isthmus, with the grand line of navigation to be established between the Arabian Gulf and the Mediterranean.

The Maritime Canal will thus be brought into communication with the heart of Egypt, by a fresh water canal, which will receive the same navigation as the Nile, and will serve also for the irrigation of large zones of the desert, exhibiting at present the most wild and desolate aspect.

Upon these data we have been instructed to make a preliminary report.

Before giving the results of our investigations, it has appeared necessary to us to justify the idea of a direct track between the two Seas; for this line never having been executed, although it is the most natural, it might be supposed that whenever the junction of the two Seas has been attempted, such difficulties have been met with, that it has been obliged to be relinquished; but this is by no means the case, as we shall presently show.

In fact, what M. Lebeau says in his _Histoire du Bas Empire_ (tom, xii., p. 490), following Abulfeda, Prince of Syria, historian and geographer, who was living in the year 753 of the Hegira, is as follows:—

“The coast at Farma (a town a little to the east of Pelusium, on the Mediterranean) was only seventy miles (106,000 _metres_) distant from the Red Sea. This space was a very smooth plain, slightly elevated above the level of the two Seas. Amrou formed the design of uniting them by a canal, which he would have filled with the waters of the Nile; but Omar having opposed it, from fear of opening an entrance into Arabia for the ships of the Christians, Amrou turned his thoughts in another direction. There was an ancient canal, called Trajanus Amnis, which Adrian caused to be brought from the Nile near to Babylon, in Egypt, as far as Pharboëtus, now Belbeïs. He met at this place with another canal, commenced by Nechos, and continued by Darius Hystaspes, and the two together discharged themselves into a lagoon of salt water, at the outlet of which Ptolemy Philadelphus caused a large trench to be made, which conducted the waters as far as the town of Arsinoë, or Cleopatris, at that part of the Gulf where Suez now is.

“The whole of this canal, being filled up with sand, had become useless at the time of the famous Cleopatra. Amrou was not deterred by the ancient prejudice, which, supposing the waters of the Red Sea to be higher than the soil of Egypt, created a fear of opening a passage for them; and he made it navigable for the transport of the corn of Egypt into Arabia. It is that which is now called Khalig, which passes through Cairo, but it only goes as far as the lagoon called the Lake of Sheib. The remainder, as far as the Red Sea, is entirely filled up, although some traces of it are still distinguishable.”

We have thought it necessary to quote the entire passage, because it clearly establishes the question of the Canal, and certain facts to which we shall return hereafter.

After Amrou came the Sultan, Mustapha III., _who took great interest in the scheme for the junction of the two Seas by the Isthmus of Suez_, and who intended to execute this work at a time of peace. (See _Mémoires sur les Turcs_, by M. De Tott, Parts iii. and iv.)

M. Lepère proposed, it is true, the track of the secondary canal between Alexandria and the interior of Egypt; but his opinion upon the direct track by the Isthmus of Suez is expressed in these terms:—

“In this project of the Canal of Suez, we have expressly based the choice of the ancient direction by the interior of the Delta towards Alexandria, upon commercial considerations peculiar to Egypt, and upon the fact that the coast near Pelusium does not appear to allow of a permanent maritime establishment. Nevertheless, we think it right to acknowledge, that, waving these considerations, it would still be easy (although, on the contrary, it appeared difficult, and even dangerous, before the invention of locks) to open a direct communication between Suez, the Bitter Lakes, and the Ras-el-Moyeh, continued upon the eastern bank of Lake Menzaleh, as far as the sea near Pelusium.

“We think that a canal opened in this direction would have an advantage _which the interior canal would not_. In fact there might be constant navigation upon it, which would not be subject to the alternations of the rising and decreasing of the Nile. It would be easy to maintain a greater depth in it than in the first canal, by means of a current fed by the immense reservoir of the Bitter Lakes.... I will add, that if I did not perceive some difficulties in excavating, and maintaining at a proper depth, the channel between Suez and the roadstead, I would propose to establish a direct communication of the two Seas by the Isthmus, for the use of corvettes and even of frigates, which would become the complement of this grand and important operation.”

It will be seen then, that M. Lepère himself acknowledged, that the direct track was the most advantageous for the commerce of the world, while the interior Canal was especially advantageous to Egypt. It is evident that with the two Canals, the one direct, on a large section, the other on a small section and derived from the Nile, all interests are most abundantly satisfied.

We will finish these observations by quoting the opinion of two distinguished staff-officers, MM. Galinier and Ferret, who have surveyed and well investigated the Red Sea. They have given a clear, rapid, and judicious analysis of the question.

“It is not in the accomplishment of this project (the interior
canal), that the real junction of the two Seas consists. This
problem will not be resolved, until the Isthmus shall present
a practicable opening, by which all ships may pass without
unloading. In order to this, it must be operated upon directly
from Pelusium to Suez; on this line the desert is narrower than
anywhere else. It is also in this direction, that the great
depression of which we have spoken extends, and at the bottom
of which the grand basin of the Bitter Lakes is situated.
Everything therefore points out this spot in the strip of land
for the construction of a canal. Everything, with one single
exception, which is, that there is not, they say, any port
at the extremity of this line of navigation; that of Suez
is partly filled up with sand, and upon the Mediterranean,
not a harbour, not a single roadstead, which now affords
any safety. Yet more, some travellers have stated, that if
it were required to form a port, it would be necessary to
contend against masses of sand, which, continually shifted
from west to east by a tolerably rapid current, seem to oppose
any maritime establishment upon that coast. In fact it is,
they say, for this reason that Alexander laid much farther to
the west the foundations of the town which bears his name,
and which he wished to become the emporium of the world. But
is the objection very serious at the present time? can the
obstacle, which occasions this anxiety, resist the constructive
means which are at the disposal of our engineers? We think
not. To create a port without the assistance of nature; to
put a restraint upon the sea; to reduce it to subjection; to
impose upon it an artificial roadstead; and to maintain that
roadstead, in spite of the natural causes operating to destroy
it: is a problem which has ceased to terrify modern art.

“Let us take the port of Pelusium,—see how easily the
difficulty would be removed! Suppose the Bitter Lakes to be
filled with the waters of the Arabian Gulf; by the action
of the tides alone, more than 700,000,000 cubic _metres_ of
water might be turned to account, the velocity of which would
constantly scour the channel, and prevent the accumulation of
sand at its mouth.

“After all that has been done by printing, the mariner’s
compass, steam,—the nineteenth century, by the realization
of this vast undertaking, would again change the face of the
globe. But, not to carry our views and our anticipations so
far, in a zone nearer at hand, Arabia and Abyssinia, the vast
country of the Gallas, the deserts of the western coast
of the Red Sea, with their roving populations, attached by
powerful ties to the vast circle of traffic which our continent
unceasingly creates and feeds—will enter into the pale of the
European world. Navigation and industry charged with the supply
of immense countries destitute of everything, will take a more
extensive range. In the wake of commerce, enlightenment and
civilization will penetrate, by degrees, that dreary night
which envelopes the Mussulman world.”

The advantage of the new track being thus sufficiently proved from a general point of view, we shall now enter into the details of the scheme with regard to its execution. We will begin with the levelling of the line from Pelusium to Suez. These levels were taken by some engineers attached to the French expedition, and the difference between the level of high water at Suez, and of low water at Tineh, was found to be 9 _met._, 90, in favour of the Red Sea. Although this result has been explained by geological and historical considerations, the fact appeared so extraordinary that several travellers came to the spot to verify it. Some English officers amongst others, operating first with the barometer, and afterwards with the boiling water process, were not able to discover any perceptible difference between the levels of the two Seas. These investigations, published in a pamphlet which has come before us, and which were known to the learned world, had occasioned much uncertainty, when, in 1847, a society established for the investigation of the Isthmus of Suez, and at the head of which were MM. Négrelli, Robert Stephenson and Talabot, caused a complete survey to be made by French engineers, under the direction of M. Bourdaloue, well known for his improved methods of levelling, and his numerous labours in that particular branch. These able and experienced surveyors, provided with good instruments, and accompanied by a numerous staff, were formed into several divisions, which operated separately, and thus were able to obtain divers verifications.

To give still greater facility and more security to the operations of the engineers, His Highness the viceroy, who had generously provided for all the requirements of the expedition, condescended to make choice of one of us to direct the whole of the operations, with the assistance of a brigade of Egyptian Engineers and a Company of artillerymen, who assisted in all the operations of levelling and verification.

M. Talabot, the engineer, in a report published in 1847, has entered into all the details of these operations, and has given an irrefutable proof of the results obtained. As these results differed very widely from those obtained by the engineers of the French expedition, it was difficult to believe in so great an error.

M. Sabatier, Consul General of France in Egypt, having been informed of the wish of some learned Frenchmen to have a fresh verification, spontaneously applied to the viceroy of Egypt, and one of us was appointed to undertake it in consequence.

The verification was made in 1853. It resulted in favour of the surveyors of 1847. For, the new levels only differ 0 _met._, 1814, from those of 1847, and give as the difference of level between the station on the quay of the hotel at Suez, and low water in the Mediterranean 2 _met._, 4286, instead of 2 _met._, 6100 found by the operations in 1847.

There cannot be a moment’s hesitation in making choice between the levellings of 1799 and those of 1847 and 1853, for the two latter were taken under the most favourable circumstances by experienced surveyors provided with the best instruments, and were verified several times without finding any perceptible difference by these various verifications; whilst the levelling of 1799 was undertaken in the midst of the vicissitudes and dangers of warfare, in a hostile country, and in a climate to which the engineers were not accustomed. One part of the operations was performed with the spirit level; another rather important portion could only be done with the water level; the surveyors frequently differed; none of the divisions of these levellings could be verified; and if the last operations had been retarded ever so little, the incidents of the war would have made them impossible; the operations had to be performed with rapidity, and the levels taken in long lengths; with frequent interruptions, and without the check of any verification. This is what M. Lepère has stated in his memorial, where he expresses himself thus:—

“Pressed for time, disturbed by the hostile demonstrations of the Arab tribes, frequently obliged to suspend operations, obliged in fine to take a great part of the observations with a water level, with no possibility of making any verification, it is not at all surprising that the able engineers who conducted these operations under such exceptional circumstances should have arrived at uncertain results.” We have therefore adopted the levels taken in 1847 and in 1853, as the only true ones, the only ones that were verified, and the only satisfactory ones. We give an abstract of them in the following table:—

STATIONS WITH THE LEVELS TAKEN IN 1853, COMPARED WITH THE LEVELS TAKEN AT THE SAME STATIONS IN 1847.

| Taken from low water | Variation
| in the Mediterranean | from the
STATIONS. | at Tineh. | Levels of
+------------+------------+
| 1853. | 1847. | 1847.
+------------+------------+-----------
Low water in the | | |
Mediterranean at Tineh. | 0 _m._ 0000| 0 _m._ 0000| 0 _m._ 0000
| | |
Stations of the German | | |
Engineers at Tineh. | 1 _m._ 5586| 1 _m._ 7400| 0 _m._ 1814
| | |
Station at the Staff 29 L. | | |
1853, point 26 of | | |
Bourdaloue’s triangulation | | |
of the most elevated Lagoons| | |
of Lake Menzaleh at Ras el | | |
Ballah. | 1 _m._ 9800| 1 _m._ 9800| 0 _m._ 0000
| | |
Station 4 L. 1853, | | |
Bourdaloue’s point | | |
A, which was found and | | |
verified. | 7 _m._ 8210| 7 _m._ 4300| 0 _m._ 3910
| | |
Bourdaloue’s Station Staff | | |
at the mouth of the Canal | | |
(this staff is not certain).| 3 _m._ 8280| 3 _m._ 0800| 0 _m._ 7480
| | |
Station 3 L. 1853, at the |16 _m._ 5950|16 _m._ 2300| 0 _m._ 3650
Serapeum, or Bourdaloue’s | 2 _m._ 4100| ---- | ----
No. 83. | | |
| | |
Upon the most elevated | 2 _m._ 0300| ---- | ----
deposits in the basin | 1 _m._ 8600| 1 _m._ 8000| 0 _m._ 0600
of the Isthmus. | | |
| | |
Station 2 L. 1853, and | | |
Bourdaloue’s Station B. | | |
30, on a block of | | |
petrified wood, covered | | |
with sandy secretions, | | |
placed upon the deposits in | | |
the basin of the Isthmus. | 2 _m._ 4380| 2 _m._ 1100| 0 _m._ 3280
| | |
Station 1 L. 1853, at the | | |
Persepolitan monument, | | |
upon a block of sandstone, | | |
south of the Bourdaloue | | |
excavations. |11 _m._ 6300|11 _m._ 3700| 0 _m._ 2600
| | |
Station on the Caravan Road, | | |
at the Staff Station, | | |
3 L. 1853. | 2 _m._ 3900| ---- | ----
| | |
Station at the staff at | | |
the starting point | | |
No. 1, L. 1853. | 1 _m._ 5186| ---- | ----
| | |
Station on the quay of | | |
the Suez hotel, the same | | |
as that of M. Bourdaloue. | 2 _m._ 4286| 2 _m._ 6100| 0 _m._ 1814

The most striking fact to be observed in the examination of this table is, the slight relief of the ground above high water of the Red Sea, in the whole extent of the Isthmus. There are only two points somewhat elevated. The first, proceeding from Suez, is met with before Lake Timsah, and is that which we shall call the Serapeum bar; its greatest elevation is 16 _met._, 5950, above low water in the Mediterranean. The second point is at the outlet of the lake, and its greatest elevation is fifteen _metres_, at the spot known as the bar of _El Guisr_; but the line of the Canal may be carried in a direction where but ten _metres_ are met with for some _kilometres_ of length. Supposing therefore the bed of the canal to be established at the depth of 6 _met._, 50, below low water in the Mediterranean, the greatest excavation would be at the bar of _El Guisr_, and would show a total depth of 16 _met._, 50, which is nothing extraordinary; supposing it even twenty _metres_, the requisite excavation would bear no comparison with what was executed in Mexico, during the Spanish occupation. For, in their then difficult position, and in the absence of tools and improved means, the Spaniards were able to effect, near the town of Mexico, which was threatened with invasion by the waters of the neighbouring lakes, the cutting of Huehuetoca, the total length of which is 20,585 _metres_, and its depth from forty-five to sixty _metres_, for a length of more than 800 _metres_, and from thirty to fifty _metres_ for a length of 3500 _metres_. And yet the expense of this work was only 31,000,000 francs.

The levelling also shows, that by adopting 6 _met._, 50, for the bed of the Canal, there will be a length of 18 _kil._ in the Bitter Lakes, where there will not be a shovelful to remove, and for another 18 _kil._ there will be very little to do; and as these lakes are dry at a depth of 8 _met._, 39, below low water, all the earth-works for the whole length of them could be performed in the dry, if found advantageous to do so.

The numerous transverse sections taken with the levelling of 1847, enable us to ascertain approximately the superfice of the Bitter Lakes at the water line. This superfice is about 330,000,000 _square metres_. If, then, the action of the tide, which brings two _metres_ of moving water, be admitted into these lakes, a disposable volume of 660,000,000 _cubic metres_ of water would be accumulated, and which might be raised to 800,000,000 by adding Lake Timsah and the retaining basins at Suez and Pelusium to these immense reservoirs.

Before pointing out the various directions of the adopted track, it appears necessary to arrive at a fixed opinion as to the formation of the Isthmus and of the downs by which it is partly covered, and also as to the accumulations of sand which exist both on the coast of Pelusium and at the bottom of the Gulf of Suez; for it is from the explanation of these phenomena that we shall start in our justification of the arrangements of the direct track in general and in detail.

By attentively observing what is passing before our eyes at the present time, in respect of the destruction and recomposition of continuity, we may come to an exact conclusion regarding the laws which operated towards the first ages of the world in the formation of alluvial lands.

Let us first examine what is going on in the English Channel; for this narrow sea having a large number of ports both on the French and English coasts, has on that account been the object of numerous observations by engineers.

The first well recognised fact is the destruction of the coast from the point of Barfleur as far as the Somme, a distance of 338 _kilometres_; and on the other side of the channel, from the Isle of Wight to Dover, a distance of 250 _kilometres_. This action is produced by the alternation of frost and thaw, by dry and moist winds, and by the saline evaporation of the sea. The abrasion observed on the coast of Calvados is an average of 0 _met._, 25, _per ann._ and on the coasts of Normandy and England 0 _met._, 30. The mean height of the cliffs on either side being sixty _metres_, it follows that the channel swallows up an amount of 10,000,000 _cubic metres_ of earth and stones every year, which must find a place somewhere.

The second fact, equally well established, and which, though opposed to the opinion of the ancients, can no longer leave any doubt on the mind, is, that rivers, with a few rare exceptions,—such as the Loire for instance,—only carry to the sea an extremely thin mud, destined to be lost in the mass of matter held in suspension by the latter; that the sands of rivers do not in general reach the sea, and that the muddy or sandy deposits observed in tidal rivers, are entirely owing to the matters brought by the tide. This discovery has been arrived at as follows.

In making the analysis of the alluvial lands forming the Bay of St. Michael, it was found that the principal substances of their formation are silex and the carbonate of lime; that the nearer the sea is approached, the more the proportion of silex increases; the more it is receded from, the more considerable the proportion of carbonate of lime becomes. Now if the basins of the three rivers which discharge themselves into this bay, the Sée, the Selime and the Couësnon, be examined, they will be found entirely destitute of calcareous substances. It is the same with the coasts of the channel and of Brittany. It cannot, therefore, be either from these rivers or from the coasts that the enormous proportion of silex proceeds which has just been described. If samples are examined with a magnifying glass, commencing with those nearest the sea, and afterwards proceeding farther into the bay, in the first, fragments of shells are perceived quite distinguishable, then these fragments are reduced and become so impalpable, that the best glass will no longer enable us to distinguish the form in the most calcareous portions.

It is, therefore, certain that the calcareous part comes exclusively from the sea, and even from the bottom of the roadstead of Cancale. As for the silex and clay, a part in their deposit may be attributed to the rivers; but it should first be understood how unimportant these three small rivers are, each discharging not more than an average of eight to ten _cubic metres_ of water per second. Farther, if the contributions of the rivers reckoned for anything in the deposits which are made in this locality, clayey or gravelly stratifications would be seen on their banks at the parts where the tide is least felt. Nothing of the kind occurs. The mixture of the calcareous matter, the grains of silex, and the argillaceous atoms is so intimate, that it is evident it could only be made at the very centre of the production of the calcareous matter; that is to say, at the bottom of the sea. If the fluviatile deposit was appreciable, it would counterbalance entirely, or in part, the calcareous overplus in the drift taken from the top of the roadstead, as compared with that taken at the bottom. Far from this being the case, the progression of the calcareous element, which can only come from the sea, is seen in proportion to the elevation of the shores. Finally, if the fluviatile deposit ought to be reckoned for anything, a larger proportion of clay would be seen upon the brink of the Sée, which traverses fissile lands, than in the neighbouring channel of the Couësnon, which traverses lands of a much harder character, furnishing less clay than the fissile ground of the Sée and the Selime. Now, the contrary is the case; the drifts of the neighbouring channel of the Couësnon are more clayey than the others, solely because this channel being more sheltered than the beds of the other two rivers, the muddy matter which the sea always holds so abundantly in suspension, and which it deposits in the basins of ports, can be carried there concurrently with the drifts.

On making the same investigations for the Seine, it was found that the sands transported by this river do not pass Rouen, and that all the accretions that are seen lower down, as far as the flats which are met with at its mouth, are deposits by the sea.

The same results were arrived at for the Scheld.

As to the Meuse and the Rhine, the following deductions have been made.

The abrasion of the coasts of the channel supplies the sea with fragments of chalk and siliceous rocks, which being rolled about by the sea become shingle. This shingle forms banks along the English and French coasts, and forced by the double action of flood and wind towards the straits it approaches them; but the shingle on the coast of France continually decreasing in size, reaches the mouth of the Somme, where it finds the point of Cayeux formed by its accumulation. Stopped at this point by the waters of the Somme, and by the change in the direction of the current of the sea which turns towards the Pas de Calais, this shingle increases the point of Cayeux, so long as its continual collision has not sufficiently reduced the size of the stones for them to be carried away by the sea; but when they are small enough, the flood bears them away and distributes them on the numerous banks which are found between the Somme and the Pas de Calais. From the inspection of Marine Charts, it is seen that the fineness of the deposit increases in proportion as these banks are nearer to the straits, and if the banks disappear in the Straits, it is because the force of the current does not allow the sands, which from being sifted for a long time have become finer and finer, to stop in that passage. They pass it therefore and some go to form the downs between Dunkirk and the Scheld, others in like manner to form downs on the English coast, others remaining in the strongest currents are carried as far as the mouths of the Humber in England, and of the Meuse and Rhine on the Continent.

If the shape of the English and French coasts to the north and south of the Straits is observed attentively, it will strike every one that those to the south are cut out into concave indentations, while those to the north all affect the convex form. It is because the coasts to the south of the Straits are abraded by the tide, and those to the north, on the contrary, are fed by the accretions. As for the muddy matters in this long course, they can only be deposited in a few perfectly tranquil creeks, or in the basins of open ports on either coast. Wherever the tide penetrates they are carried with it, and, when finally it has entered the northern sea, and made a course sufficiently long to abate its swiftness, it finds itself in an excellent condition for depositing these muddy matters, which it holds in suspension. This is what it does at the mouth of the Humber, where it completely chokes up the port of Hull.

In like manner, the muddy matters form at the mouth of the Rhine, of the Meuse, and of the Scheld, those immense polders, which constitute such an essential part of the territory of Holland, and the numerous banks at the mouth of these rivers are only composed of sand and carbonate of lime. Now the rapidity of the current, long before reaching the mouth, is not sufficiently great to carry down the sands; in fact, no trace of them is perceived; these banks are therefore the production of the sea.

Finally, in order to appreciate at the _maximum_ the power of the fluviatile deposit in the formation of the coasts, observations have been made upon the Yssel, that branch of the Rhine which discharges itself into the Zuyderzee. This sea has but very feeble tides, 0 _met._, 40, at ordinary high water, and very much resembles the Mediterranean, the Black Sea, and the Adriatic Gulf in this respect. A muddy Delta has also been formed at the mouth of the Yssel, of the same shape as those of the Rhone, the Po, the Nile, &c. &c. This Delta cannot be exclusively owing to the Yssel, because, although it is true that the tides of the Zuyderzee are very feeble, on the other hand the shores which surround it are of an exceedingly friable nature; now, however feeble the tides may be, they yet attack the banks, and what proves it, is, that the Hollanders are obliged to defend them. By considering the Delta of the Yssel as a fluviatile deposit solely, we shall therefore have an extreme case. Now, this Delta has a superfice of only 1500 _hectares_, while the superfice of the land in Holland, which is evidently of modern deposit, is at least 1,000,000 _hectares_. If it is observed that the Yssel only emits a fifteenth of the whole volume of the Rhine and the Meuse united, it will give 22,500 _hectares_ for the deposit of the river, against 1,000,000 deposited by the sea; which is scarcely two per cent. of what the sea has furnished in the formation of the polders of Holland.

From the examination of all these facts, it evidently results, as we have said, that in seas with tides, the rivers not only do not form banks, alluvium, or deltas at their mouths, but farther, that the alluvium found in the regions of these rivers submitted to the action of the tide, is deposited by the sea.

We shall now prove that these conclusions are equally true for the rivers of the Mediterranean, notwithstanding the opinion of the Italian engineers, who have considered the fluviatile origin of their deltas as demonstrated.

To give an idea of the propagation of the waves or billows of the sea agitated by the wind, they have been compared to a field of corn under the action of the air. It seems as if the ears of corn had an impulsive swiftness, which however does not exist, since they do not quit their places. Farther, if the wind is feeble, it is only the ears which waver without the stalks being shaken; but, in proportion as the wind rises, the stalks take part in the movement to a greater and greater depth down to the root.

The waves have been again compared to the movements of a cord, which is made to undulate by shaking one of its extremities in the hand. It seems as if the cord was going at a rapid rate, while in reality it does not quit the hand that shakes it, only each point of it rises and falls alternately, and this movement is the greater according as the impulse is stronger; if the extremity of the cord opposite to that which receives this impulse encounters an obstacle, as the surface of a wall for instance, it will strike it at each movement of the hand.

It is exactly the same with the waves of the sea; every fluid molecule placed at the surface of the billow experiences an oscillatory movement nearly vertical, so that if a body floating on the surface of a wave is watched it will be seen to remain in the same place, sometimes in the hollow of the wave, sometimes on its summit, and if at length it changes its place, that depends upon other circumstances, such as the force of the wind or the direction of the currents.

This oscillatory movement which is perceived on the surface of the sea, is necessarily developed to a certain depth, which will be greater in proportion as the undulations are stronger at the surface. This fact has been confirmed by experiment; it has been ascertained in effect that the agitation of the sea caused by the wind, is communicated to a certain depth, variable according to the wind, according to the sea, and the places where the observations were made, and that beyond that depth the sea is perfectly calm. Thus it may be admitted as an observed and well proved fact, that the waves require a certain depth for their free developement; if an obstacle is presented to this developement, there will be a forcible re-action of the wave against this obstacle which will be carried off, if it is moveable, and will enter into the system of the wave. This action of the waves against the deeps is what is called the _ground swell_.

This established, it has already been seen that the coast of the sea, as well as the projecting capes, resign to the sea every year a certain amount of earthy and rocky matters. These matters are removed by the waves which break upon the shore, the soft portions are quickly disintegrated by this powerful action, and form muddy sand and mud, and the hard portions are rounded into pebbles the size of which is diminished more and more by the prolonged action of the force which set them in motion and which reduces them to sand; but in proportion as these matters arrive at a sufficient degree of tenuity, they become susceptible of submitting to the transporting force of the waves and currents, and quit the place where they were formed.

This transporting force depends both upon the height of the tides and the direction of the winds, as well as their intensity, combined with that of the currents which are observed in all seas. So that while considerable masses of matter are set in motion along the shores, the rivers, especially those which traverse a great extent of country, transport as far as their mouths only muddy matters, so light that they are carried to a distance, and afterwards deposited in the depths of the sea. This is remarkably the case with the Nile, whose waters at the time of the inundation are distinguished by their colour for more than ten leagues into the sea. All the deposits and accretions of the river up to 20 _kilom._ above its mouth are muddy, while all the banks which are at its mouth are composed of sand alone.

Thus, all the impediments of the mouth of the Nile evidently emanate from the sea. To demonstrate it by still farther evidence, we will repeat the reasoning of the engineer M. Bonniceau relative to the alluvium of the river Mersey, in his excellent work upon the navigation of tidal rivers: “If the deposits emanated from the elevated lands in a sensible degree, the quantities deposited from time to time ought to be proportional to the quantity of rain that falls at the same epochs, because the same amount of matters descending from the elevated lands and transported by the river, ought to be partly regulated by the quantity of water that carries them; but it is a fact well ascertained, that the accumulations of sand which exist in the vicinity of the mouth are greater in proportion as the waters of the river are less abundant, while on the contrary at the time of the increase, when the Nile contains nearly 0 _met._ 008 of matter in suspension, the sand banks are removed and thrown back far off into the sea.”

It is said that Alexander the Great was determined in his choice of the situation for the port of Alexandria by the consideration of the winds and littoral currents which carry eastward the matters held in suspension by the Nile, and thus cover the coast with sand. If this theory were true, no alluvium ought to be perceived westward of the mouth of the river. Now all the coast from Tripoli as far as El Aritch is covered with sand banks, which frequently form downs, and these downs are found at the present time transported several leagues into the interior of the lands westward of the Rosetta mouth.

The port of Alexandria itself has not escaped the action of the ground swell, for a sand bank has been formed which occupies a good third of the total superfice of the roadstead. Happily for the port the accumulation of sand appears to have been arrested long ago, or rather its increase has become imperceptible.

The roadstead of Alexandria owes its depth to the disposition of its sides in respect to the winds and currents. It is like the roadstead of Algiers, which is everywhere very deep, while the neighbouring ports have sand banks. It cannot be said that these sand banks are owing to the presence of rivers, which do not exist in the whole extent of the coast of Barbary, for the few land streams that are scattered along the shore cannot be called by that name.

We have seen that the winds and the currents carry the detritus of the coasts reduced to sand to great distances. The currents however do not arrest the motion of the waves and the ground swell; they bend to their forms, and as their direction necessarily tends to the shore, the sands clear the currents with the ground swell which contains them, and which thus conducts them to the shore. When the direction of the waves is oblique to the coast, the sands are borne to a distance, but when it is perpendicular to the coast, the waves raise the sands brought by the ground swell into dykes and banks, which protect the low shores. The most minute and lightest portions are accumulated at the more elevated points of the flats, where, being dried by the sun, they are soon carried away by the wind, which leaves them, in its turn, in the shape of downs. The ground swell, therefore, furnishes the materials of those downs, which usually border flat shores, and it is that which has drawn from the depths of the sea the sands of those immense deserts of Africa, and of so many other plains which are found in various parts of the globe.

“Often,” says M. Jomard, “have I remained for whole hours, contemplating the origin and progress of the phenomenon of the formation of sands. I saw the waves break and deposit a small line, scarcely discernible, of very fine sand. Another wave came, burdened like the first, and this new line of sand pushed the first slightly on. This, once beyond the reach of the water, and exposed to the rays of a burning sun, was quickly dried, and became the prey of the wind, which immediately seized and carried it off into the air; the less light particles of gravel did not reach so far, but, subjected to the alternate motion, diminished more and more, and were converted by degrees into sand.”

We may also say with Colonel Emy, that

“All river bars are deposits, brought or arrested by the ground swell, and without it these deposits would be repelled into the main as far as the rivers extend their course. The Delta of the Nile, those of the Mississippi, of the Ganges, of the Scheld, of the Meuse, of the Rhine, and the Camargue of the Rhone, were originally bars formed by this same ground swell.”

The tongues of sand which separate the lake of Thau from the gulf of the Lion, the tongue of earth upon which Alexandria is built, those which separate the lakes Bourlos and Menzaleh from the Mediterranean, are bars of sand formed by the ground swell. The sand bank which separates from the Red Sea the vast basin of the Bitter Lakes, was, without any doubt, a ford elevated by the ground swell, which, in tempestuous weather, ascends this sea with the current of the tides charged with sand. The ford, which answers at the present time at Suez, was certainly formed in this manner by the ground swell.

We may say also, that the whole Isthmus of Suez was formed by the maritime deposits of the Mediterranean and of the Red Sea. We believe that, previous to historic times, the two Seas were in communication with each other, that the detritus of the chains of mountains situated to the right and left, carried down by rain, filled up the space which separates them, and that when that space was elevated to such a height that the ground swell could reach it, its action was applied in such a way that by the meeting of the swell of the two Seas, a bank was formed, which is no other than the bar of El Guisr. After the formation of this bank, the combined action of the ground swell, both on one side and the other, and the accretions from the neighbouring mountains continued until the Isthmus was dry. Then the soil thus constituted was covered by the downs, which advanced upon it from the direction of Pelusium, driven by the north winds, and from the direction of Suez, driven by the winds and currents from the south.

In this state the Isthmus is at present, and the numerous soundings which we have asked for from His Highness the Viceroy, will prove whether our hypothesis is well founded or not.

The same theory may, as Colonel Emy observes in his remarkable work, throw a new light on important geological facts:—

“For instance, those ancient and elevated plains, composed of sand and pebbles, the formation of which, it has been attempted to explain, by the revolutions of the globe and violent convulsions of nature, or which have been regarded as deposits left by rivers, appear to be maritime accretions. If is, indeed, easy to conceive rivers capable of bringing down the fragments detached from mountains, by shocks, and by the decomposition of the rocks; but how could they extend those fragments uniformly, and over spaces so extensive as the plains in question? Moreover, was not the course from the summits of the mountains generally too short for the fragments of the excessively hard rock found in some of those plains, to have time to acquire their roundness? The rivers have prolonged their courses through these accumulations of pebbles; they may, in overflowing, have covered them with sand and earth, but it is more probable that they contributed in nowise to the formation of these accretions, unless it were by transporting the rough materials to the sea. Nothing but the ground swell could spread these fragments of mountains so uniformly as they are, convert them into shingle and sand by a long trituration on the shores, where it had driven them; gather them either into banks or plains, and thus fill up spaces over which the sea formerly extended.

“The ancient collections of shingle, pebbles and sand are owing, like those at present forming in a similar manner, to maritime accretions, and must henceforth be regarded as an incontestable proof that the ocean formerly reached and was long stationary at different heights far exceeding its present level.”

It is not surprising, then, to find on divers points of the Isthmus pieces of hard stone broken into small fragments, and half rounded, covering the sand-banks at variable heights above the level of the Mediterranean.

But, be it as it may, it is certain that throughout the length of the line, from the roadstead of Suez to that of Pelusium, the excavations will only be in light earth, which can be easily removed by hand as far as the water line, and with dredges down to the bed of the Canal.

The track which we have followed for the Canal was prescribed by the very nature of the locality, and by the condition that the two Seas were to be brought into direct communication in the most economical manner.

The line begins at the roadstead of Suez, turns to the east of the town, making a curve to reach the ancient track, which it leaves to the west, and follows the channel of the valley until it joins the Bitter Lakes, which anciently formed the extremity of the gulf of the Red Sea. It traverses those lakes throughout their length, following their sinuosities, so as to avoid the inequalities of the ground. On leaving the lakes, the line crosses the bar of the Serapeum, at its lowest point, and enters Lake Timsah, leaving the heights of Cheik Ennedek to the east.

The last-mentioned lake is to serve in the formation of an inland port, in which ships may be revictualled and repaired, while it will be the point of junction between the Maritime Canal and the Canal communicating with the Nile.

In traversing this lake, the line forms several curves, in order to avoid the extensive downs which have encroached upon a part of that region.

On leaving the lake, the line proceeds to the bar of El Guisr, at its lowest point, and then goes towards Lake Menzaleh, which it follows directly along its eastern shore as far as Pelusium, and is prolonged into the sea until it reaches a depth of 7 _m._, 50.

The dimensions of the Canal have been determined by the idea of creating a grand passage for maritime navigation, open to steam and sailing vessels of considerable burthen. The Caledonian Canal is the only known analogous work. This Canal, however, is but 37 _m._ broad at the water line, and but 6 _m._, 10 deep. The locks, to the number of 23, have been enlarged so as to admit forty-four gun frigates; they are 52 _m._, 40 in length between the gates, 13 _met._ in breadth, and have a depth of water of 6 _m._, 10.

For cutting through the Isthmus of Panama by a maritime canal, as projected by Mr. Garella, it was proposed that the width of the canal, at the water line, should be 44 _met._, and the depth of water 7 _met._

Prince Louis Napoleon, who, in 1846, published a remarkable work, inserted in the _Revue Britannique_, under the title of _Canal de Nicaragua_, adopted the same dimensions as Mr. Garella, in the project which he proposed to execute for establishing the communication between the Atlantic and Pacific Oceans.

We have assumed on considerations hereinafter to be explained, that paddle and screw frigates as well as vessels of 1000 to 1500 tons, ought to be able to traverse the Canal in order to satisfy to the fullest extent the demands of navigation. We have therefore fixed the width of the Canal at the water line at 100 _met._; its _minimum_ draught of water at 6 _m._, 50, below low water in the Mediterranean. The locks, two in number, are to be 100 _met._ long, 21 _met._ wide, with a _minimum_ depth of water of 6 _m._, 50. These works will be established at the two extremities of the Canal, immediately before the dykes forming the channel which on each side unites the Canal with the two Seas. These two locks will form part of a sluiced barrage, and thus convert the whole Canal into one immense dam, receiving the waters of the Red Sea during the highest tides, and storing them up successively in order to raise the level and create a rush of water in each channel when necessary. The highest tides of the Red Sea being from 2 _met._ to 2 _m._, 50 above low water in the Mediterranean, a depth of 9 _met._ of water will be obtained in the canal at certain times, but a mean super elevation of 1 _m._ may be depended on, which will usually give a minimum depth of 7 _m._, 50 to 8 _met._ Under these conditions, screw steamers will be enabled to pass easily along the Canal without the presence of its bed re-acting in an inconvenient manner on the motion of their screws. We have, however, calculated the earth-works for three different depths of water, viz. 6 _met._; 6 _m._, 50; and 7 _met._ below low water in the Mediterranean. If the Company should require a depth of 8 _met._, it would be easy to obtain it by means of dredges, without stopping the navigation on the Canal.

The length of each barrage, including the lock, is 100 _met._; and in order farther to facilitate the entrance of the rising tide into the Canal, a third barrage has been added at Suez on the site of the existing channel. This last work will be separated from the first by a platform raised above the level of high water, so that the two together will unite the road from Cairo passing by Suez to Mecca. Its length has also been fixed at 100 _met._

For reasons of economy the width of the Canal has been reduced to 65 _met._ wherever the height of the ground reaches 6 _met._

To prevent the degradation of the banks of the Canal, the slope has been fixed at two on the base to one in height, and it is proposed to have a causeway 2 _met._ broad to receive, 1st. A covering of the broken stones found along the Canal, 2nd. Any earth falling from the higher grounds, which would otherwise encumber the bed of the Canal. This is only an imitation of what has proved so successful on the Caledonian Canal.

The width of the towing path has been fixed at 4 _met._, which is quite sufficient for a maritime canal where steam towing will be so much in use.

Lake Timsah, situated nearly midway between the two Seas, at the entrance of the _Wady Tomilat_, will form, as we have said, an inland port, to which both the outward and inward navigation will tend. On its shores will be established magazines, stables, workshops for repairs, as well as 1500 _metres_ of quay walls for mooring vessels and embarking merchandize. For, as the illustrious author of the work on the canal of Nicaragua well expresses it, the proposed Canal must not be a mere cutting destined solely to form a passage from one sea to the other for the produce of Europe, but it must make Egypt a prosperous state by enabling her to dispose of her interior produce, and a powerful one by the extent of her commerce.