# Popular Science Monthly/Volume 23/July 1883/Unwritten History

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* UNWRITTEN HISTORY.
By Professor T. H. HUXLEY.
I DOUBT not that you all joined in cheering Lord Wolseley and his companions in arms the other day, when they came to Windsor to receive their well-earned honors at the hands of the sovereign. If I had been among you I should have given a special cheer, on my own account, to the general—not so much to the successful soldier as to the man of science, who had thoroughly studied the conditions of the problem with which he had to deal; who knew what causes would produce certain desired effects; and whose experiments were followed by the predicted results more surely than sometimes happens with those which are made on a lecture-table.
But a much larger interest attaches to the day of Tel-el-Kebir, with all that preceded and followed it, than if it were an isolated experimental investigation of the great "survival of the fittest" ​problem. These events of yesterday are but the latest episodes of a struggle between the social organization of Asia and that of Europe for predominance in the countries which border the Ægean and the Levantine Seas, which has been going on for some thousands of years. To say nothing of earlier events, Marathon, Thermopylæ, Salamis, the expedition of Alexander, the Punic wars of Rome, the Saracen occupation of Spain, the Crusades, the Turkish conquest of the Balkan Peninsula, the Egyptian expedition of the first Napoleon, are names of some of the long score of matches and return-matches played between East and West in the terrible game of war. And, in my judgment, the grandson of the youngest boy here is not likely to see the winner finally declared. For the contest depends not upon mere dynastic interests, or the lust of conquest, but is the inevitable product of the struggle for existence between incompatible forms of civilization, antagonisms of religion, and antipathies of race.
Twenty-four centuries, mainly occupied in fighting, do not afford a very pleasant retrospect at the best, and it would be altogether horrible, were not the affairs of this world so ordered that "there is a soul of good in things evil." No doubt millions of men, women, and children have suffered grievous misery and wrong, and whole nations have been annihilated, as the tide of conquest, swept over them—now to the west, and now to the east. All that is sadly obvious, and, to those who can see only that which is obvious, these wars, like all others, must take the guise of purely diabolical evils. But a more patient and penetrating vision may discern that all this suffering is the school fee which the human race has had to pay for its education. As elsewhere, bright and dull pay alike, and the bright profit; which is, perhaps, no great satisfaction to the dull, but it is the rule of the school, and we have to put up with it.
In the present case, the Western nations are the bright boys. Your teachers of history are doubtless careful to point out to you all that ancient Greece owed to its intercourse, whether hostile or peaceful, with the East; all the benefit which Saracen learning on the one hand, and crusading enterprise on the other, conferred on Europe in the middle ages, and how much the Turks, quite unintentionally, did for the revival of learning. It is not to such familiar truths as these that I wish to direct your attention, but rather to the fact that history, in the modern sense of the word, was born of the very earliest of the struggles to which I have adverted.
I say history, in the modern sense of the word, that is, not barely a chronicle of events and record of current traditions or venerable myths, but a narrative based upon evidence which has been critically sifted, and in which the narrator endeavors to trace, amid the tangled occurrences of human life, the thread of natural causation which connects them with the needs and the passions of men. The chronicler is more or less of a gossip, the historian more or less of a man of science. For ​that which constitutes a man of science is not the pursuit of this or that specialty, but a living faith in the supreme importance of truth, and an unshakable conviction that order reigns over all things, and that chance has no more place in human affairs than elsewhere.
Now, the generation of the science of history took place in this wise: Somewhere in the earlier half of the fifth century, a sort of side skirmish of the Persian wars drove out of house and home a Greek gentleman—one Herodotus, with whose name you will be sufficiently familiar. He was a man of great intelligence and unflagging energy, well versed in all the learning of his time. The magnitude and the interest of the events which bad taken place, either within his own memory or within that of men with whom he had talked, seem early to have taken strong hold of his mind, and he determined to devote his life to writing an account of them, in which truth should be sifted from error, and the causation of events displayed to the best of his ability.
With this end in view, Herodotus was not content with collecting and collating all the information which he could obtain from trustworthy sources, but he determined to become personally acquainted with the chief countries and people implicated in the contest. There lay the primary conditions of the problem which "the father of history" had set himself to study; and there is no better evidence of his strong scientific turn than the conviction on which he acted, that, if he would understand these conditions, he must know them of his own knowledge.
Egypt was one of the countries involved in the Persian wars. Herodotus visited the country somewhere about 450 b. c., and he has left a most curious and entertaining account of his own observations, and of the information which he obtained from the priests of Thebes and the literati of Heliopolis, with whom, his interpreter, or dragoman, as we should now call him, brought him into contact.
I dare say you read the second book of Herodotus, and know a great deal more about it than I do. Nevertheless, it may not be superfluous to remind you that the historian speaks with admiration of the learning of the Egyptians, and of the remarkable pains which they took to preserve the memory of the past in their records. Among a great many other things, they read to him from a papyrus the names of three hundred and thirty monarchs who had reigned over Egypt, from Menes, the first Pharaoh, to their own time.
The average length of the reigns of any long series of Western sovereigns is about twenty-five years, so that, if the records of the Egyptians were to be trusted and the average length of reign among them was the same, Menes should have ascended the throne more than ten thousand years ago.
Within my recollection it was very much the fashion to regard Herodotus as a garrulous old gentleman, who willingly allowed himself ​to be crammed with interesting fictions; and the pretension of the Egyptians to such prodigious antiquity of their state was regarded as one of the most patent examples of such figments. Yet it is probable that, in respect of this and other pieces of information of like character, the learned Egyptians said no more, not only than they fully believed, but than they might fairly enough think they had good reason for believing; and modern investigations have shown that they were certainly much nearer the truth than sundry of their critics.
Among the achievements of scientific method in this century, none is, to my mind, more wonderful than the disinterment of so much of a past, to all appearance hopelessly dead, by the interpretation of the hieroglyphic and cuneiform inscriptions in which the ancient inhabitants of the valleys of the Nile and the Euphrates chronicled the events of their history. Thanks to the sagacity and the untiring toil of such men as Lepsius—just about to receive the congratulations of all the world on the completion of half a century of fruitful labor—of Birch, of Mariette, of Brugsch, the student of Egyptology, guided by the spirit of scientific criticism, is probably far more accurately informed about the ancient history of Egypt than was the whole College of Heliopolis in Herodotus's time.
An exact chronology of Egyptian history is yet to be constructed; but those best qualified to judge agree that contemporary monuments tell us of the state of Egypt more than five thousand years ago; and since they prove, beyond the possibility of doubt, that the people who erected them possessed a complex social organization, as replete with all the necessaries and conveniences of life as that of any nation in Europe in the middle ages, and not inferior in literature or in skill in the arts of painting, sculpture, and architecture, it is but rational to conclude that, even at this farthest point of time to which written records take us, the Egyptian people had, for long ages, left barbarism behind, and constituted a settled and a civilized polity. So that, whether Menes was followed by three hundred and thirty kings or not, the general impression of the vast antiquity of the Egyptian state which Herodotus received, and has transmitted to us, has full justification.
But that which is so characteristically modern about Herodotus is that he was not satisfied to stop where written records halt, or to accept traditional accounts of an earlier time without discussion. His informants told him that, when Menes began to reign, Lower Egypt was covered with water, a dismal and pestilent swamp, and that the first Pharaoh drained and rendered habitable that alluvial soil which they called "the gift of the Nile."
Herodotus was evidently very much interested in this statement. Perhaps he asked his Heliopolitan friends how they knew this. Perhaps they answered him as they did a countryman of his, "You Greeks always were and always will be children," asking the why of the wherefore. A true saying, which, however it may have been intended, ​conveys high praise. For it is just because it is true that these mighty children became the fathers of natural knowledge. Men of science are eternal children, always asking questions of Mother Nature, and never content with her answers.
But, whether questions are childlike or childish, depends upon the knowledge and the intelligence of the questioner; and Herodotus, as I have said, was largely endowed with both. Let me remind you that he lived midway between Thales and Aristotle, in the very heart and center of the great age of Greece; and let me also remind you of the fact, of which people too often remain ignorant throughout their school and university career, that, if this was an epoch of great achievements in art, in literature, and in philosophy, it was no less distinguished for the sedulous cultivation of physical science. Democritus, the contemporary of Herodotus, was the great exponent of principles which have played, and still play, a great part in modern scientific speculation. Half a century before Herodotus, Xenophanes had observed petrified marine shells and fish-bones in the quarries of Syracuse and elsewhere; he had drawn the conclusion that the rocks in which they were contained were the hardened mud of the bottom of the sea in which the corresponding animals once lived; and he had laid down the general proposition that the geographical features of our earth are not constant, but that where land now is, sea has been, and where sea is, land has been. And it is a corollary from this proposition that the land which constitutes any country has not always been what it is and where it is, but that it has a history, unwritten save in the hieroglyphics of Nature. Herodotus is not likely to have been ignorant of the speculations of Xenophanes, but it is in evidence that his extensive travels had enabled him to observe facts which led directly to like conclusions. The plain of Ilium and the estuary of the Mæander had shown him rivers at work in the formation of new land, and he adverts to the conclusions to be drawn from the presence of shells in the rocks which bound the Nile Valley.
To a mind thus prepared by an acquaintance with elementary truths of physical science, the first glance at Egypt can not fail to suggest inquiry, and, in fact, Herodotus says as much:
"Any one who sees Egypt, without having heard a word about it before, must perceive, if he has the least intelligence, that the Egypt to which the Greeks go in their ships is a gift of the Nile to the Egyptians." That is to say, as he elsewhere explains, the rich soil of the great plain, or so-called Delta of Egypt, has been formed out of the deposits left by the Nile during the annual inundation. The region occupied by the delta, he adds, was "evidently, at one time, a gulf of the sea. It resembles, to compare small things with great, the parts about Ilium and Teuthrania, Ephesus, and the plain of the Mæander. In all these regions the land has been formed by rivers, whereof the ​greatest is not comparable in size with any one of the arms of the Nile." After comparing the valley of the Nile with that of the Red Sea (which Herodotus appears not to have visited, and of the magnitude of which he has a very inadequate conception), he goes on to say: "Now, if the Nile should choose to divert his waters from their present bed into the Arabian Gulf, what is to prevent it from being filled up by the stream within twenty thousand years at most? For my part, I think it might be filled up in half the time. Why, then, should not a gulf of even much larger size have been filled up in the ages before I was born, by a river which is so large and so given to working changes as the Nile?"
It is on the strength of these very sound and just physical considerations that Herodotus tells us he accepted Egyptian tradition:
"Thus I gave credit to those from whom I received this account of Egypt, and am myself, moreover, strongly of the same opinion, since I remarked that the country projects into the sea farther than the surrounding shores, and I observed that there were shells upon the hills." Finally, he inquires into the origin of the population of Egypt:
"I do not believe that the Egyptians came into being at the same time as the delta. I think they have always existed, ever since the human race began. As the land went on increasing, part of the population came down into the new country, part remained in the old settlements."
Thus Herodotus commits himself to four very definite propositions respecting the unwritten history of Egypt:
1. That the delta was once an arm of the sea.
2. That it has been filled up and converted into dry land by the alluvial deposits of the Nile.
3. That this process of conversion into dry land probably took something like twenty thousand years.
4. That the Egyptians existed before Lower Egypt, and migrated thence from Upper Egypt.
And it will be observed that the first three of these propositions at any rate are not mere guesses, but conclusions based upon a process of reasoning from analogy, just as sound in form as any which is to be met with in the discussion of a similar problem in a modern treatise on geology.
Herodotus wrote twenty-three hundred years ago. In the course of twenty-one out of the twenty-three centuries which have elapsed since his time, I am not aware that any one rose above his level in the discussion of such problems as that which he attacked. And some quite modern writers have not yet reached it, for lack of as much knowledge of natural phenomena as Herodotus possessed. Let us look at the facts by the light of such knowledge of elementary physical science as is now happily accessible to every Etonian.
​It has often been said, and with perfect truth, that Egypt is a land by itself, unlike any other part of the world. On approaching Alexandria from the sea, nothing can be less attractive than the flat shore which stretches east and west as far as the eye can reach, without an elevation of more importance than bare and barren sand-dunes to break its even line. This monotonous coast extends for two hundred miles between the most extreme of the ancient arms of the Nile, from the Canopic in the west to the Pelusiac in the east, and forms the northwardly turned base-line of the triangular area of Lower Egypt, the shape of which led the Greeks to call it the delta.
In the journey from Alexandria southward to Cairo, the traveler finds himself in a boundless plain, as flat as the flattest part of Lincolnshire or of Holland. At first, rising only here and there above the level of the Mediterranean, it is full of morasses and stagnant lakes of great extent, the waters of which vary from salt to fresh, and from fresh to salt, according as the Nile or the Mediterranean is the predominant contributor to their contents. Beyond this region, the wide expanse of black alluvial soil, intersected by innumerable water-courses, departs from absolute horizontality, rising some three or four inches in the mile. Here and there, low mounds bearing groups of date palms, or thickets of sycamores and acacias, indicate the deserted site of an ancient city, or preserve from the periodic floods the assemblage of hovels which constitutes a modern Egyptian village. In autumn, the soil, save these mounds and their connecting dikes, disappears under the overflow of the flooded Nile; in early spring, the exuberant vegetation of the young crops no less completely hides it under a carpet of the brightest imaginable green.
For more than a hundred miles, as the crow flies, this is the general character of the country between Alexandria and Cairo. But, long before the latter city is reached, the plain begins to be limited by distant heights which spring up on either hand. First, a ridge of low hills makes its appearance on the western or Libyan side; and then, a range of more distant but bolder and loftier heights shows itself, far away, on the eastern or Arabian horizon. With every advance southward the plain diminishes in extent, while its Libyan and Arabian boundaries approach, until, at Cairo, they are not more than six or seven miles apart.
Nothing can be more sharply contrasted than the aspect of the plain and that of its limitary heights. For the low, rounded ridges on the west and the higher plateau with its steep and cliffy face on the east are utterly waterless—mere wastes of bare rock or sand—without a bush or a patch of soil on which it could grow, to veil their savage nakedness. Under our own pale and faintly-lighted sky, such bare hills and rugged cliffs as those which bound the prospect here and everywhere in Upper Egypt would fitly represent the abomination of desolation. But, framed as they are in an atmosphere of limpid purity, ​with lights and shades and tints endlessly varying in shape and hue, from hour to hour, and almost from minute to minute, as the sun runs his course, they have a strange and unique beauty. Moreover, in early spring, the edges of the greenery of the plain lie sharply defined against the yellow sands and gray-brown stones of the waste as if it were so much water.
When I was in Cairo, ten years ago, I delighted in wandering about the heights of the Mokattam range, which rise for some four or five hundred feet immediately to the east of the city. The Sahara itself can not better deserve the name of desert than do these stony solitudes. Looking westward at sunset, the vultures, diminished to mere crows, wheeled about the face of the cliffs far below. Beneath and beyond them, the green expanse stretched northward, until it became lost in the horizon; while, toward the west, its even line followed the contour of the Libyan shore, as if it were the veritable seawater of the Gulf of Herodotus. And sharply defined against the western sky, the great pyramid, which, even in its present mutilated state, reared its summit to the level of my eye, threw its long shadow eastward like the gnomon of an appropriately gigantic dial-plate.
Indeed, the comparison is not far-fetched. For the great shadow has veritably swept, from west to north and from north to east, day after day from the dawn of civilization till now; since the toiling subjects of Chufu, with patient and skillful labor, piled the great stones of his tomb, one upon another, it has marked the birth-hour, and sometimes the death-hour, of each great nation known to history.
For all these ages, day after day, the shadow, as it lengthened eastward, has swept over the weary heads of thousands upon thousands of orderly, cheerful, hard-working men, women, and children, who have been plundered, starved, beaten, decimated, now to serve the ambition or gratify the superstitious vanity of an ancient Pharaoh, and now to enable some thinly varnished savage of a modern Khedive to subsidize his opera troupe in Cairo, and squander the price of their blood among foreign harlots and foreign swindlers.
Six thousand years of grinding oppression, worse than it ever was during the last few centuries, seemed to me a curious reward for laying the foundations of civilization; and yet there was no sign that the great shadow was likely, for another century or so, to mark the hour when Khedive, mudirs, commercial Mamelukes of various nationalities, and all the rest of the "wolves that with privy paw devour apace and nothing said" should be swept away to make room for that even moderately decent and intelligent rule which is all the Egyptian people need to become, at last, a contented and a wealthy nation.
But this, I say, was ten years ago; many things—Tel-el-Kebir among the rest—have happened since then; and perhaps the good time may be coming. At any rate, the great British panacea—constitutional government—is to be administered; and if the Fellaheen ​sheep do not find their affairs much improved when the representatives of their interests are mostly mongrel Arabo-Turkish wolves (as they certainly will he), they must he unfit for free institutions, and we may wash our hands of them, conscious that we have exhausted the resources of political science in our intelligent efforts to improve their condition.
The extent of the land now under cultivation in Egypt is estimated approximately at 7,300 English square miles that is to say, its area is about a fifth greater than that of the valley of the Thames (6,160 square miles). One half of this cultivated land lies in the delta, and the other half in Upper Egypt. Under the Pharaohs, the cultivated area was of considerably greater extent; but not even the industry and thrift of the Fellaheen have been able to make head against the ignorance, sloth, and greed of their later rulers.
Above Cairo, the Libyan and the Arabian boundaries of the narrow valley of Upper Egypt, which runs in a southerly direction, through 6 of latitude to Assouan in 24° north, are approximately parallel, here approaching and there diverging from one another, though they are rarely more than ten or fifteen miles apart. The general inclination of the bottom of the long and winding stream, though rather greater than in the delta, does not exceed five or six inches in the mile. Hence, Assouan, some five hundred miles distant, in a direct line, from Alexandria, is little more than three hundred feet above the Mediterranean.
In Upper Egypt there is still less rain than in the delta. For, though violent storms, accompanied by a heavy down-pour, occur at intervals of perhaps twenty years, filling the parched ravines of the desert with short-lived torrents, there is usually either no rain, or, at most, a passing shower, in the course of each year. Hence, not only the boundaries of the valley, but all the country eastward as far as the Red Sea, and all westward (save where a rare oasis breaks the monotony of the waste) for hundreds of miles across the Sahara, over which the same meteorological conditions prevail, is, if it be possible, even more arid and barren than the desert which bounds the delta.
What are known as the "tombs of the kings" are excavated in the walls of a deep gorge which runs from the plain of Thebes far into the Libyan Hills, the steeply escarped faces of which rise twelve hundred feet above the river. From the summit of one of these hills a panorama of appalling desolation presents itself. Except where the Kile lies like a brown ribbon, with a broader or narrower green fringe on either side, north, south, east, and west, the eye rests on nothing but rugged heights of bare rock, separated by a perfect labyrinth of steep-walled valleys. Baked during the day by a cloudless sun, cooled, not unfrequently down to the freezing-point, at night by radiation through the vaporless air, the surface-rocks are shattered by the rapid ​expansion and contraction which they undergo, as if they had been broken by a road-maker's hammer; and the fragments collect in great heaps at the bottom of every steep incline. Not a blade of grass, not a drop of water, is to be seen anywhere; and yet the form and arrangement of the ravines are such that it is impossible to doubt that they have been formed, like other valleys, by the scoring and denuding action of rapid streams.
I remember that one day, wandering in the desert, northeast of Cairo, in the direction of the petrified forest, I was exceedingly struck with the resemblance of the superficial scorings of the surface of the rocky soil to those which are ordinarily made by rain. I was puzzling myself to account for the fact, when a sudden storm, accompanied by very heavy rain, came up, drenched me to the skin and vanished, all in less than an hour. Immediately after the rain began to fall, every one of the ramified scorings which had interested me was filled by a stream of water, rushing to join with its fellows and flow down some bigger groove to a lower level. It was obvious that the resemblance which had struck me was not deceptive, and that all these ramified scorings were miniature "wadys"—the dry beds of minute rivulets produced by former sudden showers of the same sort as that which I had experienced.
It was a capital lesson in physiography, and I did not forget it when I looked down on the great wadys of the Libyan desert at Thebes. Twelve hours' heavy rain would send a roaring torrent, sweeping before it all the accumulated débris of years, down every one of them. And if we suppose the process repeated only every twenty years; still, since the Libyan Hills have been where they are for the last ten thousand years, five hundred repetitions of the application of this most efficient rain-plow would have cut some pretty deep furrows, even if, during all this time, rain has never been more frequent or more abundant than it is now.
Still farther to the south, about El Kab, close upon the twenty-fifth parallel of latitude, the fringe of cultivable land which borders the Nile becomes narrower and narrower, and the limestones in which the valley has hitherto been excavated are replaced by sandstones as far as Assouan. The low hills of such rock (rarely more than two hundred feet high) which lie on each side of the river at Gebel Selsileh, about forty miles north of Assouan, approach one another so closely that the gorge through which the stream passes is little more than one thousand feet wide. There is every reason to believe that the opposite walls of this gorge were once continuous, and that the river swept as a rapid over the correspondingly elevated margin of the sandstone plateau, through which it has since cut its channel back to Assouan, until, at present, its bed, for the forty miles to that place, has no greater inclination than elsewhere.
Near Assouan, under the twenty-fourth parallel, on the frontier of ​Nubia, the granitic masses of the desert on the eastern or Arabian side spread suddenly to the westward, and come to the surface in place of the sandstones. In the course of the six or seven miles between Assouan and Philæ the bed of the river rises sixteen feet, forming a declivity, down which the stream rushes in a rapid, known as the First Cataract. The alluvial soil has almost vanished, and the river flows amid a confused heap of granite blocks, with black and polished surfaces. For some eight degrees of latitude farther south, the granite and sandstone plateau which rises so suddenly at Assouan extends through Nubia, increasing in elevation, until at the foot of the second cataract (Wady Haifa) the level of low Nile reaches 392 feet; at the third cataract, 659 feet; at the fourth, 745 feet. Where the White and Blue Niles join, just below Khartoum, in 16° north, the river is 1,212 feet above the sea, or more than 900 feet above its height at Assouan.
Throughout the whole of this course the Nile receives but one affluent, the Atbara, which carries the drainage of a part of Abyssinia into it in about 18° north. And, as this solitary tributary is wholly inadequate to make good the loss which the main stream suffers by evaporation and percolation, on its course through thirteen degrees of one of the hottest and driest climates in the world, the Nile presents the singular spectacle of a river the volume of water in which is conspicuously less than that poured into it by its feeders.
The Blue and the White Niles, which unite to form the main stream close to Khartoum, are in fact very large rivers, each of which drains an immense area abundantly supplied with water. The one receives the overflow of the great equatorial Nyanza lakes and the drainage of the vast swampy region of the Soudan to the north of them, in which the heavy intertropical summer rains accumulate. The other is fed not only by such rains, but by the snows among the mountain-tops of Abyssinia, which melt as the sun advances to the northern tropic.
The height of the water in the Nilometer at Cairo is contingent upon the meteorological conditions of a region more than a thousand miles off; and the question whether Egypt shall have a year of famine or a year of plenty hangs upon the rainfall in Abyssinia and equatorial Africa. It is as if the prosperity of the agricultural interest in Berkshire depended on the state of the weather in Morocco.
The general course of the Nile is so directly north and south that the thirtieth parallel of east longitude, which traverses the Albert Nyanza Lake on the equator, passes close to the Rosetta mouth at its outfall. The Albert Nyanza is 2,500 feet above the sea; and, since the length of the part of the great circle inclosed between the points ​just mentioned is more than two thousand English miles, the mean inclination of the river, if it ran straight, would somewhat exceed a foot per mile. Taking the actual bends into consideration, however, it must be considerably less than this amount.
Without a knowledge of the facts thus briefly sketched, the periodical inundation of the valley of Egypt by the Nile is unintelligible. And, since no one till long after Herodotus's time possessed such knowledge, we may proceed to consider this singular phenomenon without troubling ourselves about his curious speculations as to its causes.
In the month of May and the beginning of June, the Egyptian Nile is little better than a great sluggish ditch, the surface of which, in Upper Egypt, lies many feet below that of its steep banks of irregularly stratified mud and sand. A short distance north of Cairo, it divides into two main branches, which take a northerly course through the delta and finally debouch, the one at Rosetta and the other at Damietta. Innumerable artificial canals connect these arms of the Nile with one another, and branch off east and west for purposes of irrigation; while, in the north, the complex system of water-courses communicates with the series of lakes and marshes, from Mariout, on the west, to Menzaleh on the east, which, as I have already said, occupy a large portion of the area of the delta southward of the sea-coast.
In the latter part of June, about the time of the summer solstice, the motion of the torpid waters of the Nile seaward is quickened, and their level rises, while at the same time they take on a green color. The rise and the flow quicken, and the green color is succeeded by a reddish brown; the water becomes turbid and opaque, and is found to be laden with sediment, varying in consistency from moderately coarse sand, which falls to the bottom at once when the water is still, to mud of impalpable fineness which takes a long time to subside. In fact, when the sun approaches the northernmost limit of his course, as the snows of Abyssinia begin to melt, and the heavy intertropical rains set in, a prodigious volume of water is poured into the White and Blue Niles, and drives before it the accumulated living and dead particles of organic matter which have sweltered in the half-stagnant pools and marshes of the Soudan during the preceding six months. Hence, apparently, the preliminary flow of green water. The Blue Nile and the Atbara must sweep down a vast quantity of river-gravel from the Abyssinian uplands, but it may be doubted whether any of this gets beyond the middle cataracts, except in the condition of fine sand. And I suspect that the chief part, if not the whole, of the coarse sediment of the waters of the high Nile must be derived from Nubia, from the weathering of the rocks, by the heating and cooling process already described, and the action of the winds in blowing the sand thus produced into the stream. The Nile continues to rise for three ​months until the autumnal equinox, by which time the level of its surface at Assouan is usually forty feet, at Thebes thirty-six feet, at Cairo twenty-four or twenty-five feet, and at Rosetta four feet higher than it is in May; and, before reaching the delta, it flows at the rate of three or four miles an hour.
Under these circumstances, the river overflows its banks on all sides. When it does so, the movement of the water is retarded or even arrested, and the suspended solid matters sooner or later fall to the bottom, and form a thin layer of sandy mud. When the Nile waters spread out over the great surface of the delta, the retardation is of course very marked. The coarse sediment is soon deposited, and only the very finest particles remain in suspension at the outflow into the Mediterranean. As the sun goes southward, his action on the Abyssinian snows diminishes, the dry season sets in over the catchment basin of the White Nile, and the water-supply of the Nile diminishes to its minimum. Hence, after the autumnal equinox, the Nile begins to fall and its flow to slacken, as rapidly as it rose. By the middle of November, it is half-way back to its summer level, and it continues to fall until the following May. In the dry air of Nubia and of Egypt, evaporation is incredibly rapid, and the Nile falls a prey to the sun. As the old Egyptian myth has it, Osiris is dismembered by Typhon.
Relatively to the bulk of water, the amount of solid matter transported annually by the Nile must be far less than that which is carried down by the rapid streams of mountainous countries in temperate climates—such, for example, as the upper Rhône. We have no very satisfactory estimate of what that amount may be, but I am disposed to think that the ordinary computation, according to which the average deposit over the delta amounts to not more than a layer one-twentieth of an inch thick annually, is, at any rate, not under the mark.
But this is a very interesting question, for it is obvious that, if we may assume that the deposit of the Nile has taken place uniformly at a known rate, it becomes possible, given the thickness of the alluvial deposit in the delta, to calculate the minimum time occupied in its formation. The borings made under the direction of the late Mr. Leonard Horner in the upper part of the delta, and those subsequently conducted by Figari Bey, favor the conclusion that the natural loose soil which fills the flat basin of the delta nowhere exceeds sixty feet in depth. Assuming it to have this thickness in any spot, it follows that, at one twentieth of an inch of deposit per annum, it must have taken at least fourteen thousand four hundred years to accumulate to that thickness at that place. And if so, Herodotus seems, at first, to have made a wonderfully good guess, when he said that the Arabian Gulf and, by implication, that of the delta, might have been filled up in "twenty thousand years, or even half the time."
​I am afraid, however, that any such modern estimate has not a much surer foundation than the ancient guess. For, in the first place, there are many reasons for believing that the action of the Nile has not been uniform throughout the whole period represented by the deposit of alluvium; and, in the second place, if it had been, the simple process of division of the total thickness of the alluvium by that of the annual deposit does not by any means necessarily give the age of the whole mass of alluvium in the delta, or, in other words, the time which elapsed during the filling of the delta, as it is sometimes supposed to do.
According to Figari Bey, the deepest, and therefore earliest, alluvium in the delta contains gravel and even bowlders; so that, if these are fluviatile beds, which is, perhaps, not quite certain, they indicate that, at the time when they were deposited, the current of the Nile in this region was much more powerful than it is now, and, consequently, that its annual additions were much more considerable.
If the flow of the Nile in these ancient times was more rapid, the probabilities are that the volume of its waters was greater, and sundry observations have been adduced as evidence that such was the case. Thus, at Semneh, above the second cataract, Lepsius, many years ago, discovered inscriptions of a Pharaoh of the twelfth dynasty, Amenemhat III, who reigned between 2,000 and 3,000 b. c, which registered the level of the highest rise of the Nile at that time. And this level is nearly twenty-four feet higher than that of high Nile at the same place now. Another fact has been connected with this. Between the narrow gorge of the Nile at Selsileh and the first cataract, alluvial deposits, containing shells of animals now living in the river, lie on the flanks of the valley, twenty to thirty feet above the point which high Nile reaches at the present day. It has been suggested that, before the Nile cut the gorge, the sandstone bar at Selsileh, as it were, dammed up the Nile, and caused it to stand at a higher level all the way back to Semneh. But, as the late Dr. Leith Adams long ago argued, the sandstone strata of Selsileh could hardly have played the part thus assigned to them. The deposits in question indicate that the supposed barrier at Selsileh was about thirty feet high; while Semneh is at least one hundred and thirty feet higher than Selsileh.
The cause of the difference of level of the Nile at Semneh, between the days of Amenemhat and now, is surely rather to be sought in the progressive erosion of the Nubian valley. If four thousand years have elapsed since Amenemhat reigned, the removal of one thirteenth of an inch per annum from the bed of the river will be more than enough to account for its present depression. Considering the extraordinary activity of the denuding forces at work in Nubia, I see nothing improbable in this estimate. But, if it is correct, there is no need to suppose that the Nile conveyed a greater body of water four thousand years ago than it does now. Nor is there anything in ​the ancient records of Egypt which lends support to such an hypothesis.
But we are indebted to Dr. Leith Adams for proof that the Nile, between the first and the second cataracts, once stood very much more than twenty-five feet above its present level. From Assouan to Derr, in fact, he observed abundant patches and continuous terraces of alluvium, containing shells of the same kinds of fresh-water mollusks as those which now inhabit the Nile, one hundred to one hundred and twenty feet above the highest level now reached by its waters; and he concludes that "the primeval Nile was a larger and more rapid river than it is now." I am disposed to think that the "primeval" Nile was so, but I question whether these terraces were made by the river in its youth. I see no reason why they should not be affairs of a geological yesterday—say, a mere twenty or thirty thousand years ago.
There can be no reasonable doubt of the correctness of the view first, so far as I am aware, distinctly enunciated by M. Louis Lartet, that the whole of the principal valley of the Nile has been excavated by the river itself. I am disposed, for my own part, to think that the Nile might have done this great work if the mass of its waters had never been much greater than now. And, with respect to the innumerable lateral ravines which debouch into the main valley, I think it-would not be safe to affirm that they could not have been excavated by the rains, even if the meteorological conditions of the country had never been very widely different from what they are now.
But, in some parts of Lower Egypt, and in the peninsula of Sinai, many of the dry wadys exhibit such massive deposits of more or less stratified materials, that it is hardly credible they can have been formed under anything like existing conditions. Indeed, in some localities, very competent observers have considered that there is good evidence of the former existence of glaciers in the valleys of Sinai. And it is well worthy of consideration whether, as Fraas and Lartet have suggested, these deposits were not contemporaneous with the so-called glacial epoch, when the climate of Northern Europe resembled that of Greenland, and when the Mediterranean covered the Sahara and washed the western flanks of the Libyan range.
Under such changed conditions, Egypt must have been one of the wet countries of the world, instead of one of the driest; and, as there need have been no diminution in the bulk of water poured in by the White and Blue Niles, the accumulation of water in the valley of Egypt partly in virtue of its own rainfall, and partly by the ​diminution of evaporation, may have been immense. Under such circumstances, it is easily conceivable that a swift and voluminous torrent, periodically swollen by the contributions of the great southern affluents, covered the delta with a permanent inundation, and swept down gravel and bowlders into the lowest part of its course.
That the outflow of the Nile once extended far beyond its present limits appears to be certain, for a long, deep, dry valley so like an ancient river-bed that the Arabs call it the Bahr-bela-Ma, or waterless river—runs from south to north in the Libyan desert along the western edge of the delta, and ends in the Mediterranean shore beyond Taposiris, far to the west of the Canopic mouth, the most westerly of the outlets of the Nile known during the historical period. And, in the extreme east, far beyond the most easterly arm known to the ancients—in fact, in the middle of the Isthmus of Suez, about Lake Timseh—alluvial deposits, containing Nile shells and hippopotamus bones, show that the Nile once extended into this region, and perhaps poured some portion of its waters into the Red Sea, by way of anticipating the engineering operations of more modern days.
These facts tend to show that any calculation of the age of the delta, based upon the present action of the Nile in the way indicated, may need to be abbreviated. But, on the other hand, there are many obvious considerations which tend the other way.
It is easy to see that the time required for the deposition of a certain thickness of alluvial soil, in any one part of the delta, can only be a measure of the time required to fill up the whole, if the annual sediment is deposited in a layer of even thickness over the entire area. But this is not what takes place. When the river first spread out from the southern end of the delta, it must have deposited the great mass of its solid contents near that end; and this upper portion of the delta must have been filled up when the lower portion was still covered with water. And, since the area to be covered grew wider, the farther north the process of filling was carried, it is obvious that the northern part of the delta must have taken much longer to fill than the southern. If we suppose that the alluvium about Memphis was deposited at the rate of one twentieth of an inch per annum, and that there are fifty feet of it, ten thousand years may be the minimum age of that particular part of the delta; but the age of the alluvium of the delta as a whole must be very considerably greater. And indeed there are some indications that the shore-line of the nascent delta remained, for a long time, in the parallel of Athribis, five-and-twenty miles north of Cairo, where the remains of a line of ancient sand-dunes are said to attest the fact. Hence, all attempts to arrive at any definite estimate of the number of years since the alluvial plain of the delta began to be formed, are frustrated. But, the more one thinks of the matter, the more does the impression of the antiquity of the plain grow; and I, for my part, have no doubt that the extreme term imagined by ​Herodotus for the filling up of the Arabian Gulf—twenty thousand years—is very much below the time required for the formation of the delta.
Thus far we have traced the unwritten history of Egypt, and the gulf of the Mediterranean, postulated by Herodotus, is not yet in sight. Nevertheless, at a much more remote epoch—in that called miocene by geologists—the gulf was assuredly there.
Near the tombs of the Caliphs at Cairo (according to Schweinfurth, two hundred feet above the level of the Mediterranean), in the neighborhood of Sakkarah and in that of the great pyramids, the limestone rocks, which look so like a sea-shore, were found by Professor Fraas to display the remains of a veritable coast-line. For they exhibit the tunnels of boring marine mollusks (Pholades and Saxicavæ), and they are incrusted with acorn-shells, as if the surf had only lately ceased to wash them. At the feet of these former sea-cliffs lie ancient sandy beaches, containing shells of oysters, scallops, and other marine mollusks, with the skeletons of sea-urchins. The specific characters of these marine organic remains leave no doubt that they lived during the miocene, or middle tertiary, epoch. Marine beds of the same age occur at Ain Musa, between Cairo and Suez.
There can be no question, therefore, that, in the miocene epoch, the valley of the delta was, as Herodotus thought it must have been, a gulf of the sea. And, as no trace of marine deposits of this, or of a later age, has been discovered in Upper Egypt, it must be assumed that the apex of the delta coincides with the southern limit of the ancient gulf.
Moreover, there is some curious evidence in favor of the belief that, at this period, however remote as measured by our standards of time, the Nile flowed down from Central Africa as it flows now, but probably in much larger volume. Every visitor to Cairo makes a pilgrimage to the "petrified forest," which is to be seen in the desert a few miles to the northeast of that city. And indeed it is a spectacle worth seeing. Thousands of trunks of silicified trees, some of them twenty or thirty feet long, and a foot or two in diameter, lie scattered about and partly imbedded in the sandy soil. Not a trunk has branches, or roots, or a trace of bark. None are upright. The structure of wood, which has not had time to decay before silicification, is usually preserved in its minutest details. The structure of these trunks is often obscure, as if they had decayed before silicification; and they are often penetrated, like other decayed wood, by fungi, which, along with the rest, have been silicified.
​Similar accumulations of fossil wood occur on the western side of the delta, about the Natron Lakes and in the Bahr-bela-Ma.
All these trunks have weathered out of a miocene sandstone; and it has been suggested that, when this sandstone was deposited, the Nile brought down great masses of timber from the upper country, just as the Mississippi sweeps down its "rafts" into the Gulf of Mexico at the present day; and that a portion of these, after long exposure and knocking about in the flood, became silted up in the sandy shores of the estuary.
The greater part of the "petrified forest" is at present one thousand feet above the level of the sea, in the midst of the heights which form the eastward continuation of the Mokattam. It has, therefore, shared in the general elevation of the land which took place after the beginning of the miocene epoch. That such elevation occurred is proved by the fact that the marine beds of that period lie upon the upraised limestone plateau of Lower Egypt; and it must have reached seven or eight hundred feet, before the Pholades bored the rocky shore of the gulf of the delta.
A flood of light would be thrown on the unwritten history of Egypt by a well-directed and careful re-examination of several points, to some of which I have directed your attention. For example, a single line of borings carried across the middle of the delta down to the solid rock, with a careful record of what is found at successive depths; a fairly exact survey of the petrified forest, and of the regions in which traces of the ancient miocene sea-shore occur; a survey of the Selsileh region, with a determination of the heights of the alluvial terraces between this point and Semneh; and an examination of the contents of the natural caves which are said to occur in the limestone rocks about Cairo and elsewhere—would certainly yield results of great importance. And it is to be hoped that, before our occupation of the country comes to an end, some of the many competent engineer officers in our army will turn their attention to these matters.
But, although so many details are still vague and indeterminate, the broad facts of the unwritten history of Egypt are clear enough. The Gulf of Herodotus unquestionably existed and has been filled up in the way he suggested, but at a time so long antecedent to the farthest date to which he permitted his imagination to carry him, that, in relation to it, the historical period, even of Egypt, sinks into insignificance.
However, we moderns need not stop at the time when the delta was a gulf of the sea. The limestone rocks in which it is excavated and which extend east, west, and south for hundreds of miles, are full of the remains of marine animals, and belong, the latest to the eocene, the oldest to the cretaceous formation. The miocene gulf of the delta was, in fact, only the remains of the wide ocean which formerly extended from Hindostan to Morocco; and at the bottom of which the ​accumulation of the shells and skeletons of its denizens gave rise to the ooze, which has since hardened into chalk and nummulitic limestone. And it is quite certain that the whole of the area now occupied by Egypt, north of Esneh, and probably all that north of Assouan, was covered by tolerably deep sea during the cretaceous epoch. It is also certain that a great extent of dry land existed in South Africa at a much earlier period. How far it extended to the north is unknown, but it may well have covered the area now occupied by the great lakes and the basins of the White and Blue Niles. And it is quite possible that these rivers may have existed and may have poured their waters into the Northern Ocean, before the elevatory movement—possibly connected with the outpour of the huge granitic masses of the Arabian range and of Nubia—commenced, which caused the calcareous mud covering its bottom to become the dry land of what is now the southern moiety of Upper Egypt, some time toward the end of the cretaceous epoch. Middle and Northern Egypt remained under water during the eocene, and Northern Egypt during the commencement, at any rate, of the miocene epoch; so that the process of elevation seems to have taken effect from south to north at an extremely slow rate. The northward drainage of the equatorial catchment basin thus became cut off from the sea by a constantly increasing plain sloping to the north. And, as the plain gradually rose, the stream, always flowing north, scooped the long valley of Nubia and of Egypt, and probably formed a succession of deltas which have long since been washed away. At last, probably in the middle, or the later part, of the miocene epoch, the elevatory movement came to an end, and the gulf of the delta began to be slowly and steadily filled up with its comparatively modern alluvium.
Thus, paradoxical as the proposition may sound, the Nile is not only older than its gift, the alluvial soil of Egypt, but it may be vastly older than the whole land of Egypt; and the river has shaped the casket in which the gift lies out of materials laid by the sea at its feet in the days of its youth.
The fourth problem of Herodotus—the origin and the antiquity of the Egyptian people—is much more difficult than the other three, and I can not deal with it at the end of a discourse which has already extended to an undue length.
But I may indicate a few cardinal facts which bear on the discussion.
According to Figari Bey's investigations, a marine deposit, which probably is of the same age as the miocene beaches of Cairo and Memphis, forms the floor of the delta. Above this, come the layers of sand with gravel already mentioned, as evidencing a former swifter flow of the river: then follow beds of mud and sand; and only above these, at three distinct levels, evidences of human handiwork, the last and latest of which belong to the age of Ramses II.
​It is eminently desirable that these statements should be verified, for the doubts which have been thrown, to some extent justly, upon various attempts to judge the age of the alluvium of the Nile do not affect the proof of the relative antiquity of the human occupation of Egypt, which such facts would afford; and it is useless to speculate on the antiquity of the Egyptian race, or the condition of the delta when men began to people it, until they are accurately investigated.
As to the ethnological relations of the Egyptian race, I think all that can be said is, that neither the physical nor the philological evidence, as it stands, is very satisfactory. That the Egyptians are not negroes is certain, and that they are totally different from any typical Semites is also certain. I am not aware that there are any people who resemble them in character of hair and complexion, except the Dravidian tribes of Central India, and the Australians; and I have long been inclined to think, on purely physical grounds, that the latter are the lowest and the Egyptians the highest members of a race of mankind of great antiquity, distinct alike from Aryan and Turanian on the one side, and from negro and negrito on the other. And it seems to me that the philologists, with their "Cushites" and "Hamites," are tending toward a similar differentiation of the Egyptian stock from its neighbors. But, both on the anthropological and on the philological sides, the satisfactorily ascertained facts are few and the difficulties multitudinous.
I have addressed you to-night in my private capacity of a student of nature, believing, as I hope with justice, that the discussion of questions which have long attracted me would interest you. But I have not forgotten, and I dare say you have not, that I have the honor to stand in a very close official relation to Eton as a member of the Governing Body. And I have reason to think that, in some quarters, I am regarded as a dangerous member of that body, who, if he were not restrained by his colleagues, would endeavor to abolish the traditional studies of the school, and set the sixth form working at the generation of gases and the dissection of crawfishes, to the exclusion of your time-honored discipline in Greek and Latin.
To put the matter very gently, that statement is unhistorical; and I selected my topic for the discourse which I have just concluded, in order that I might show you, by an example, the outside limits to which my scientific fanaticism would carry me, if it had full swing. Before the fall of the second empire, the French liberals raised a cry for "Liberty as in Austria." I ask for "Scientific Education as in Halicarnassus," and that the culture given at Eton shall be, at any rate, no narrower than that of a Greek gentleman of the age of Pericles.
Herodotus was not a man of science, in the ordinary sense of the word; but he was familiar with the general results obtained by the "physiologists" of his day, and was competent to apply his knowledge ​rationally. If he had lived now, a corresponding education would certainly have put him in possession of the very simple facts which I have placed before you; and the application to them of his own methods of reasoning would have taken him as far as we have been able to go. But, thirty years ago, Herodotus could not have obtained as much knowledge of physical science as he picked up at Halicarnassus in any English public school.
Long before I had anything to do with the affairs of Eton, however, the Governing Body had provided the means of giving such instruction in physical science as it is needful for every decently-educated Englishman to possess. I hear that my name is sometimes peculiarly connected (in the genitive case) with certain new laboratories; and, if it is to go down to posterity at all, I would as soon it went in that association as any other, whether I have any claim to the left-handed compliment or not. But you must recollect that nothing which has been done, or is likely to be done, by the Governing Body, is the doing of this or that individual member; or has any other end than the deepening and widening of the scheme of Eton education, until, without parting with anything ancient that is of perennial value, it adds all that modern training which is indispensable to a comprehension of the conditions of modern life.—Macmillan's Magazine.
* ↑ A lecture to the Eton Volunteer Corps, with some additions.
* ↑ Those and other citations are taken from Rawlinson's "Herodotus."
* ↑ The heights of points in the course of the Nile, given in books, are widely discrepant and usually very inaccurate. I am indebted to the eminent civil engineer, Mr. John Fowler, for this and subsequent precise determinations. The height of low Nile above the sea is 303 feet at Assouan, 319 feet at Philæ.
* ↑ "Essai sur la Géologie de la Palestine et des Contrées avoisinantes, telles que l'Egypte et l'Arabie," 1869. The Rev. Barham Zincke, in his interesting work "Egypt of the Pharaohs," 1871, has expressed similar conclusions; and I may say that they forced themselves on my own mind in the course of my journey to the first cataract in 1872.
* ↑ See Unger, "Der versteinerte Wald bei Cairo," "Sitzungsberichte der Wiener Akademie," 1858. Dr. Schweinfurth ("Zur Beleuchtung der Frage ueber den versteinerten Wald," "Zeitschrift der deutschen geologischen Gesellschaft," 1882) considers that the trees grew where they are found, but his arguments do not appear to me to be convincing.