Vain, indeed! A philosopher of the present age would be thought mad who should rely on a system so contrary to experiment and observation; though Thales, the propagator of this now mentioned, was so highly esteemed for his knowledge.
The next opinion quoted is that of Anaxagoras, who attributes the inundation of the Nile to snow melting in Ethiopia; and this Diodorus contradicts, for a very substantial reason, that there is no snow in Ethiopia to melt. But supposing all the mountainous part of Ethiopia north of the Line, that is all Abyssinia, were covered with snow, then the inundation must happen in other months, as it must begin in January, for the sun being then within few degrees of being vertical, it must have been the very height of flood when the sun passed over that country in April; whereas its increase is not discerned till about June, when the sun has left the zenith of all Abyssinia, having then passed over Nubia, and is standing vertical to Syene, or as far to the northward as it can proceed.
It is not my meaning to maintain that there never was snow in Abyssinia, as climates have wonderfully changed. In Cæsar’s time, the greatest rivers in the Gaul almost every year were frozen over for months, so that armed nations, with their families, cattle, and incumbrances, passed regularly over them upon the ice without fear; an event that happens not now once in a century. In Prussia138 also were found white bears, an animal now confined to the severest snowy regions of the north; and, what comes still nearer to the present subject, in the inscription found in Abyssinia by Cosmas Indoplaustes, Ptolomæus Evergetes, speaking there, in the first person, of his own conquests in Ethiopia, says, that he had passed the river Siris, and had entered the kingdom of Samen, a country intolerable on account of cold and deep snow.
This account I think almost incredible. Ptolemy parted from Egypt, his fleet coasting along the Red Sea, opposite to his army, and carrying provisions for it; we know, moreover, the time his ships sailed, the beginning of June, when the Nile was overflowed, and consequently of great utility to his army on the first part of his expedition, while he was in Egypt and part of Nubia. Now supposing him to pass the desert as quickly as possible, and come to Axum, it must have been then Summer, or near it; and as it was necessary his fleet should return by the monsoon in October, so it must have then rained continually, and the sun been perpendicular to the country when he found the deep snows in Samen, which is not very probable. The river Tacazzé, moreover, which Ptolemy crossed, was really not passable at that time, and no Abyssinian army did ever attempt it during a flood, though, without, scruple at all seasons they cross the Nile when most deep and rapid.
I remember that when I first ascended Lamalmon, the highest mountain of that ridge, running the whole length of the province of Samen, it was in the depth of winter; the thermometer stood at 32°, wind N. W. clear and cold, but attended with only hoar frost, though at that height, and at that season; the grass scarcely was discoloured, and only felt crisp below my feet, with this small degree of freezing; but this vanished into dew after a quarter of an hour’s sun, nor did I ever see any sign of congelation upon the water, however shaded and stagnant, upon the top of that, or any other hill. I have seen hail indeed lie for three hours in the forenoon upon the mountains of Amid Amid.
The opinion of Democritus was, that the overflowing of the Nile was owing to the sun’s attraction of snowy vapour from the frozen mountains of the north, which being carried by the wind southward, and thawed by warmer climates, fell down upon Ethiopia in deluges of rain: and the same is advanced by Agatharcides of Cnidus in his Periplus of the Red Sea. This opinion of Democritus, Diodorus attempts to refute, but we shall not join him in his refutation, because we are now perfectly certain, from observation, that Democritus and Agatharcides both of them had fallen upon the true causes of the inundation.
I shall now mention a treatise of a modern philosopher, wrote expressly upon this subject, I mean a discourse on the causes of the inundation of the Nile, by M. de la Chambre, printed at Paris in quarto, 1665, where, in a long dedication, he modestly assures the king, he is persuaded that his majesty will consider, as one of the glories of his reign, the discovery of the true cause of the Nile’s inundation, which he had then made, after it had baffled the inquiry of all philosophers for the space of 2000 years; and, indeed, the cause and the discovery would have been both very remarkable, had they been attended with the least degree of possibility. M. de la Chambre says, that the nitre with which the ground in Egypt is impregnated, ferments like a kind of paste, occasioning the Nile to ferment likewise, and thus increases the mass of water so much, that it spreads over the whole land of Egypt.
Far be it from me to bear hard upon those attempts with which the ancients endeavoured to solve those phænomena, when, for want of a sufficient progress in experimental philosophy and observation, they were generally destitute of the proper means; but there is no excuse for a man’s either believing or writing, that earth, impregnated with so small a quantity of any mixture as not to be discernible to the eye, smell, or taste, could periodically swell the waters of a river, then almost dry, to such an immensity, as to cover the whole plains of Egypt, and discharge millions of tons every day into the sea, at the same time that it contributed to the health of the people and the fertility of the land. It puts me in mind of an assertion of M. de Maillet, almost as absurd as de la Chambre’s treatise, that the Nile, which in Egypt is the only fountain of pleasure, of health, and plenty, has a mixture of one tenth of mud during the time of the inundation: pleasant and wholesome stream, truly, to which Fleetditch would be Hippocrene.
But whatever were the conjectures of the dreamers of antiquity, modern travellers and philosophers, describing without system or prejudice what their eyes saw have found that the inundation of Egypt has been effected by natural means, perfectly consonant with the ordinary rules of Providence, and the laws given for the government of the rest of the universe. They have found that the plentiful fall of the tropical rains produced every year at the same time, by the action of a violent sun, has been uniformly, without miracle, the cause of Egypt being regularly overflowed.
The sun being nearly stationary for some days in the tropic of Capricorn, the air there becomes so much rarified, that the heavier winds, charged with watery particles, rush in upon it from the Atlantic on the west, and from the Indian Ocean on the east. The south wind, moreover, loaded with heavy vapour, condensed in that high ridge of mountains not far south of the Line, which forms a spine to the peninsula of Africa, and, running northward with the other two, furnish wherewithal to restore the equilibrium.
The sun, having thus gathered such a quantity of vapours as it were to a focus, now puts them in motion, and drawing them after it in its rapid progress northward, on the 7th of January, for two years together, seemed to have extended its power to the atmosphere of Gondar, when, for the first time, there appeared in the sky white, dappled, thin clouds, the sun being then distant 34° from the zenith, without any one cloudy or dark speck having been seen for several months before. Advancing to the Line with increased velocity, and describing larger spirals, the sun brings on a few drops of rain at Gondar the 1st of March, being then distant 5° from the zenith; these are greedily absorbed by the thirsty soil, and this seems to be the farthest extent of the sun’s influence, capable of causing rain, which then only falls in large drops, and lasts but a few minutes: the rainy season, however, begins most seriously upon its arrival at the zenith of every place, and these rains continue constant and increasing after he has passed it, in his progress northward. Before this, green boughs and leaves appear floating in the Bahar el Abiad, and shew that, in the latitude where it rises, the rains are already abundant. The Galla, who inhabit, or have passed that river, give account of its situation, which lies, as far as I could ever calculate, about 5° from the Line.
In April, all the rivers in Amhara, Begemder, and Lasta, first discoloured, and then beginning to swell, join the Nile in the several parts of its course nearest them; the river then, from the height of its angle of inclination, forces itself through the stagnant lake without mixing with it. In the beginning of May, hundreds of streams pour themselves from Gojam, Damot, Maitsha, and Dembea, into the lake Tzana, which had become low by intense evaporation, but now begins to fill insensibly, and contributes a large quantity of water to the Nile, before it falls down the cataract of Alata. In the beginning of June, the sun having now passed all Abyssinia, the rivers there are all full, and then is the time of the greatest rains in Abyssinia, while it is for some days, as it were, stationary in the tropic of Cancer.
These rains are collected by the four great rivers in Abyssinia; the Mareb, the Bowiha, Tacazzé, and the Nile. All these principal, and their tributary streams, would, however, be absorbed, nor be able to pass the burning deserts, or find their way into Egypt, were it not for the White River, which, rising in a country of almost perpetual rain, joins to it a never-failing stream, equal to the Nile itself.
In the first days of May, the sun, in his way to the northern tropic, is vertical over the small village of Gerri, the limit of the tropical rains. Not all the influence of the sun, which has already past its zenith, and for many days has been as it were stationary within a few degrees of it over Syene, in the tropic of Cancer, can bring them one inch farther to the northward, neither do any dews fall there as might be reasonably expected from the quantity of fresh and exhalable water that is then running in the Nile, though it passes close by that village, and after, through that wild and dreary desert. The fact is certain, and surely curious; the cause perhaps unknown, although it may be guessed at.
I conceive, that mountains are necessary to occasion either rain or dew, by arresting and stopping the great quantity of vapour which is here driven southward before the Etesian winds. Now, all that country between Gerri and Syene is flat and desert, so that this interruption is wanting; and it is owing to the same cause, that the bounds of the tropical rains do stop farther to the southward as you travel westward, and in place of lat. 16°, which is their limits at Gerri, they are confined within lat. 14° in that part of the kingdom of Sennaar which lies south and west of that capital, where all is free from mountains till you come to those of Kuara and Fazuclo.
Yet although the sun’s influence when at its greatest, is not strong enough to draw the boundaries of the summer’s rain farther north than Gerri, all the time that it is in the tropic of Cancer at its greatest distance, these rains are then at their heaviest throughout all Abyssinia; and Egypt, and all its labours, would soon be swept into the Mediterranean did not the sun now begin to change its sphere of action by hastening its progress southward.
From Syene the sun passes over the desert, and arrives at Gerri; here he reverses the effects his influence had when on his passage northward; for whereas, in his whole course of declination northward, from the Line to Gerri, he brought on the rains at every place where he became vertical, so now he cuts off those rains the instant he returns to the zenith of each of those places passing over Abyssinia in his journey southward, till arrived at the Line, in the autumnal equinox, his influence ceases on the side of Abyssinia, and goes to extend itself to the southern hemisphere. And so precisely is this stupendous operation calculated, that, on the 25th of September, only three days after the equinox, the Nile is generally found at Cairo to be at its highest, and begins to diminish every day after.
Thus far as to the cause and progress of the Nile’s inundation in our northern hemisphere; but so much light and confirmation is to be drawn from our consideration of the remainder of the sun’s journey southward, that I am persuaded my following him thither will require no apology to my philosophic or inquisitive reader.
Immediately after the sun has passed the Line he begins the rainy season to the southward, still as he approaches the zenith of each place; but the situation and necessities of this country being varied, the manner of promoting the inundation is changed. A high chain of mountains run from about 6° south all along the middle of the continent towards the Cape of Good Hope, and intersects the southern part of the peninsula nearly in the same manner that the river Nile does the northern. A strong wind from the south, stopping the progress of the condensed vapours, dashes them against the cold summits of this ridge of mountains, and forms many rivers which escape in the direction either east or west, as the level presents itself. If this is towards the west, they fall down the sides of the mountains into the Atlantic, and if on the east, into the Indian Ocean. Now all these would be useless to man, were the Etesian winds to reign, as one would think must be the case, analogous to what passes in Egypt; nay, if any one wind prevailed, these rivers, swelled with rains, would not be navigable, but another wise and providential disposition has remedied this.
The clouds, drawn by the violent action of the sun, are condensed, then broken, and fall as rain on the top of this high ridge, and swell every river, while a wind from the ocean on the east blows like a monsoon up each of these streams in a direction contrary to their current, during the whole time of the inundation, and this enables boats to ascend into the western parts of Sofala, and the interior country to the mountains, where lies the gold. The same effect, from the same cause, is produced on the western side towards the Atlantic; the high ridge of mountains being placed between the different countries west and east, is at once the source of their riches, and of those rivers which conduct to the treasures which would be otherwise inaccessible in the eastern parts of the kingdoms of Benin, Congo, and Angola.
There are three remarkable appearances attending the inundation of the Nile; every morning in Abyssinia is clear, and the sun shines. About nine, a small cloud, not above four feet broad, appears in the east, whirling violently round as if upon an axis, but, arrived near the zenith, it first abates its motion, then loses its form, and extends itself greatly, and seems to call up vapours from all opposite quarters. These clouds having attained nearly the same height, rush against each other with great violence, and put me always in mind of Elisha foretelling rain on Mount Carmel139. The air, impelled before the heaviest mass, or swiftest mover, makes an impression of its own form in the collection of clouds opposite, and the moment it has taken possession of the space made to receive it, the most violent thunder possible to be conceived instantly follows, with rain; after some hours, the sky again clears, with a wind at north, and it is always disagreeably cold when the thermometer is below 63°.
The second thing remarkable is the variation of the thermometer; when the sun is in the southern tropic, 36° distant from the zenith of Gondar, it is seldom lower than 72°; but it falls to 60° and 59° when the sun is immediately vertical; so happily does the approach of rain compensate the heat of a too-scorching sun.
The third is, that remarkable stop in the extent of the rains northward, when the sun, that has conducted the vapours from the Line, and should seem, now more than ever, to be in possession of them, is here over-ruled suddenly, till, on its return to the zenith of Gerri, again it resumes the absolute command over the rain, and reconducts it to the Line to furnish distant deluges to the southward.
I cannot omit observing here the particular disposition of this peninsula of Africa; supposing a meridian line, drawn through the Cape of Good Hope, till it meets the Mediterranean where it bounds Egypt, and that this meridian has a portion of latitude that will comprehend all Abyssinia, Nubia, and Egypt below it, this section of the continent, from south to north, contains 64° divided equally by the equator, so that, from the Line to the southmost point of Africa, is 32°; and northward, to the edge of the Mediterranean, is 32° also: now, if on each side we set off 2°, these are the limits of the variable winds, and we have then 30° south, and 30° north, within which space, on both sides, the trade-winds are confined; set off again 16° from the 32°, that is, half the distance between the Cape of Good Hope and the Line, and 16° between the Line and the Mediterranean, and you have the limits of the tropical rains, 16° on each side of the equator: again, take half of 16°, which is 8°, and add it to the limit of the tropical rains, that is to 16°, and you have 24°, which is the situation of the tropics.—There is something very remarkable in this disposition.
It is here we shall discuss a question often agitated, whether Egypt owed its existence to the Nile, and whether it was formerly an arm of the sea, but in process of time, being filled up by the quantity of mud which the Nile deposited in its inundation, it at length became firm land, above the surface of the waters? I believe this is the general opinion, as well of the books, as of the greatest part of travellers of the present age; it therefore merits examination, whether it is founded in fact and observation, or whether it is to be ranked among the old and ill supported traditions fancifully now again brought into fashion.
Egypt is a valley bounded on the right and left by very rugged mountains; it must, therefore, occur to any one that the Nile, being a torrent falling from very high ground in Ethiopia, were this valley concave, the violent rapidity, or motion, would be much likelier to carry away mud and soil, than to leave it behind in a state to accumulate.
The land of Egypt slopes gently from the middle of the valley to the foot of the mountains on each side, so that the center is really the highest part of the valley, and in the middle of this runs the Nile140. At right angles with the stream large trenches are cut to the foot of the mountains, in which canals the water enters, and insensibly flows down to the end of these trenches, where it diffuses itself over the level ground.
As the river swells, these canals fill with water, which goes seeking a level to the foot of the mountains; so that now the flood, which begins to restagnate towards the bank of the river, acquires no motion, as the calishes are formed at right angles to the stream. Sometimes, indeed, the river is so high, when the rains in Ethiopia are excessive, that the back-water joins the current of the Nile, when immediately it communicates its motion to the stagnant water, and sweeps away every thing that is planted into the sea. It is a mistake then to assert,—the fuller the Nile, the better for Egypt.
It has been said by various authors, that it was necessary Egypt should be measured every year, on account of the quantity of mud which the Nile brought down by its inundation, which so covered the land-marks, that no proprietor knew or could discover the limits of his own farm, and that this annual necessity first gave rise to the science of Geometry141. How or when Geometry was first known and practised, is not my business in this place to inquire, though I think the origin here given is a very probable one. The land of Egypt was certainly measured annually: it is as certainly so at this very time; and if so, the present reason for this is probably the very one which first gave rise to it; but that this is not owing to the mud of the Nile, will appear on the slightest consideration; for if Egypt increase a foot in a hundred years, one year’s increase of soil could be but the one hundredth part of a foot, which could hide no land-mark whatever; and we see to this day those in Egypt were huge blocks of granite often with gigantic heads at the end of them; which the Nile, at the rate Herodotus fixes, of a foot in 100 years, as being added to the soil, would not cover in several thousand years.
It is absurd to suppose that the Nile is to bring down an equal quantity of soil every year from the mountains of Abyssinia; whatever was the case at first when this river began to flow, we are sure now, that almost every river and brook in Abyssinia runs in a bed of hard stone, the earth having been long removed; and the rivers now cannot furnish from their rocky beds what they first did from their earthy bottoms, when Egypt was supposed, according to Herodotus, to have its foundation laid in the floods; and therefore, on the first consideration, this annual and equal increase must be impossible.
At Basboch, before the Nile enters Sennaar, I made several hundred trials upon its sediment, as it then came down from the cultivated country of Abyssinia; I thereby found this sediment surprisingly small, being a mixture of fat earth, and a small quantity of sand. At the junction of the Nile and Astaboras I did the same, taking up the water from the middle of the stream, and, having evaporated it afterwards, I found little more sediment than at Sennaar; the water was indeed whiter, and the greatest part of the sediment was sand. I repeated this experiment at Syené with the utmost attention, where the Nile leaves Nubia, and enters Egypt, and I found the quantity of sediment fully nine times increased from what it was at Sennaar, and in it only a trifle of black earth, all the rest being sand. The experiment at Rosetto was not so often repeated as the others; but the result was, that, in the strength of the inundation, the sediment consisted mostly of sand, and, towards the end, was much the greater part of earth. I think these experiments conclusive, as neither the Nile coming fresh from Abyssinia, nor the Atbara, though joined by the Mareb, likewise from the same country, brought any great quantity of soil from thence.
It was at Syené that the water should have been most charged with mud, for all the accession it was to bring to Egypt was then in its stream; but there the chief part of the sediment was sand, fanned and ventilated with perpetual hot winds, and spread on the surface of the burning desert, never refreshed with the dew of heaven. In that dreary desert, between Gooz and Syene, we saw huge pillars of this light sand; their base in the earth, and heads in the clouds, crossing the wide expanse in various directions, and, upon its becoming calm in the evening, falling to pieces, and burying themselves in the Nile, with whose stream they mixed like an impalpable powder, and were hurried down the river, to compose the many sandy islands we see in the course of it.
It seems to be an established fact, that water of every sort, fresh and salt, that of rivers, and what is stagnant, has from early times sensibly diminished through the whole world; if then the land of Egypt has been continually rising every year, while the quantity of water that was to cover it has become less, or at least not increased, dearth in these latter years must have been frequent in Egypt, for want of the Nile’s rising to a proper height; but this is so far from being the case, that, in these last 34 years142, there has not been one season of scarcity from the lowness of the Nile, although the rise having been too great, and the waters too abundant, have thrice in that time occasioned famine by carrying away the millet.
If the land of Egypt increased (as Herodotus says) one foot in 100 years, this addition must have appeared in the most ancient public monuments: now, the very base of all the obelisks in Upper Egypt, are bare and visible, and even the paved plane, laid visibly on purpose to receive the Gnomonical shade, is not covered, nor scarcely out of its level, and these small deviations are apparently owing to the falling of neighbouring buildings. There are in the plain, immediately before Thebes, two Colossal statues143, obviously designed for Nilometers, covered with hieroglyphics, as well as more modern inscriptions; these statues are uncovered to the lowest part of their base; whereas we should have now been walking on ground nearly equal in height to their heads. The same may be said of every public monument, if there had been any truth in the surface of Egypt increasing a foot in a hundred years.
It appears, at least as far as Hadrian’s time, that if the pecus of the Greeks be the peek of the present Egyptians, the same quantity of water overflowed Egypt as now.
The advocates for the supposed increase of the land of Egypt on a foot in 100 years, pressed by this observation, which they cannot contradict, have chose to evade it, by supposing, without foundation, that a smaller measure of the Nile’s increase had been introduced by the Saracens to obviate the Nile’s scantiness, and this has landed them in a palpable absurdity; for, while the Nile failed, the introduction of a lesser measure would not have increased the crop; and, if the quantity of grain had been exacted when it was not produced, this would have only doubled the distress, and made it more apparent; this would never have occasioned the joyful cry, Wafaa Ullah, God has given us our desire, men Jibbel, alla Jibbel, the Nile has overflowed, from the mountains on one side of the valley to the mountains on the other. Besides, there is no country in the world, perhaps, but where this trick may be played with impunity, except in Egypt, for a reason that I am about to explain.
The extension of the land of Egypt northward, the distance between it and Cyprus, and the situation of Canopus, all shew, that no or very little alteration has been made these 3000 years. Dr Shaw, and the other writers, who are advocates for what has been advanced by Herodotus144, that Egypt hath been produced by the Nile, have deserted this ground of maintaining their hypothesis, and have recourse to the Nilometer to prove, that the soil has increased in height, and that a greater quantity of water is necessary now to overflow the land of Egypt than was required in the days of Homer.
If the first part of their assertion can be proved, I shall make no sort of difficulty of giving up the other. But I rather conceive, that none of those who have written upon this subject hitherto, whatever degree of learning and information they may have possessed, have possessed sufficient data to explain this subject intelligibly. It seems, indeed, to have remained with the source of the river, a secret reserved for latter times.
It will be necessary for us first to consider what the use of a Nilometer was, for what cause it was made, and by whom.
It is scarcely necessary to observe, that, in every state or society, the product or revenue should be known, as well as what will be wanted for the supply of the necessities of the people. Now, it was only the ground overflowed by the Nile that could produce grain for the subsistence of the inhabitants and revenue of the state.
The first consideration, then, was, to know how much of the land of Egypt was overflowed in a given term of years, and how much grain was produced upon that average. This could only be ascertained by measuring, and they, therefore, settled with precision the land that was overflowed from the earliest times, and do so to this day. These actual measurements gave them a maximum and a minimum, which furnished them with a mean, and thus they were in possession of all the principles necessary for making a Nilometer, by dividing a pillar into corresponding cubits, and divisions of cubits called digits, placing it also firm and perpendicular, so as to be liable to no alteration or injury, though in the middle of the stream.
The first stated measure was certainly that mentioned in scripture, the cubit, secundum cubitum virilis manus, measuring from the center of the round bone in the elbow to the point of the middle finger145. This is still the measure of all unpolished nations, but no medium or term, expressive of its exact contents, having been applied, writers have differed as to the length of this cubit, and no standard existing to which it might be referred, a great deal of confusion has thereupon followed. Dr Arbuthnot146 says, that there are two cubits in scripture, the one, 1 foot 9 inches, and 888/1000 parts of an inch, according to our measure, being the 4th part of a fathom, twice the span, and six times the palm. The other is equal to 1 foot 824/1000 parts of a foot, or the 400dth part of a stadium. I shall not inquire into the grounds he goes on; I believe, however, that neither are precisely the ancient cubit of the east, but both are too large; at least the Egyptian I found to be very exactly 1 foot 5⅗ inches, which is 2 inches more than father Mersenne147 has made his Hebrew cubit. But this is of less consequence to us now, because Herodotus148 informs us, that in his time, and probably at the first institution of a Nilometer, the measure was the Samian cubit, which is about 18 inches English, or half an inch less than the ancient cubit.
The reader will then consider, that the divisions of this Nilometer were a representation of certain facts: That the Nile’s reaching to such a division corresponded to a certain quantity of corn that was sown, a proportion of the produce of which was to be paid to the king, the rest to go to the landlord and the labourer.
The Nilometer then ascertained the contract between king and people on these terms, That, in the event of so much corn being produced by the land of Egypt, such a tribute was to be paid: But, in case a certain quantity of ground, less than that, was overflowed, or, which is the same thing, a lesser quantity of grain was produced, then the king was not to exact his tribute, because it was understood such a quantity only was produced as was sufficient for the maintenance of the landholder and labourer. This was referred to the Nilometer, whose division shewed to what height the Nile had risen. Men appointed by the sovereign were to superintend this Nilometer, and to publish the height of the Nile, whilst the reason why the king was to have the direction of the Nilometer, and not his subjects, was very obvious, though it has not yet been understood, because the king could not gain by substituting false measures, whereas the people might.
The Nile, though in an average of years it brought down nearly the same quantity of water, yet, in particular ones, it varied sometimes more and sometimes less. It is likewise observed, like most other rivers, to run more on one side of the valley for some years than to the other. The consequence of this varying and deviation was, that though, upon the whole, the quantity indicated by the Nilometer was the same, yet nobody knew his quota, or what proportion of the whole was drawn from the property of each individual; as for this they were obliged to apply to actual mensuration. Supposing a man’s property was a section of the land of Egypt, of 12,000 feet from the brink of the river to the mountain, and of any given breadth, 4000 feet of this perhaps were overflowed, whilst the other 8000 remained dry, and above the level of the water. The tenant, after having measured, did not till then know what his farm of 12,000 feet would give him for that year, only 4000 of which had been overflowed by the water, and was then fit for sowing; for this he paid his landlord the highest rent laid upon cultivated land. But the 8000 feet that still remained were not equally useless, though not overflowed by the inundation; for 4000 of the 8000, which lay by the bank of the river, could be overflowed by machines, and by the labour of man, when, for a certain time, the river was high enough to be within reach of machinery; so that the value of this 4000 feet to the farmer was equal to the first, minus the expence and trouble it cost him for watering it by labour; for this, then, he paid one half of the rent only to the landlord.
Now, though it was known that the whole farm was 12,000 feet, yet, till it was measured, no one could say how much of that would be overflowed by the Nile alone, and so manured without expence; how much was to be watered by labour, and so pay half rent; and how much was to be incapable of any such cultivation, and for that year equally useless to landlord and tenant. I speak not of a fact that happened in antiquity, but one that is necessary and in practice at this very hour; and though a man, by this mensuration, attains to the knowledge of what his farm produces this same year, this is no general rule, as his cultivated land next year may be doubled, or perhaps reduced to one-fourth; and his neighbour, on the other side of the Nile, may in his farm make up the correspondent deficiency, or excess; and the average quantity produced by them both being the same, the degree of the Nilometer will be the same likewise.
From this it is obvious to infer, that there are two points of great advantage to the tenant: The one is, when it is just high enough not to pay the meery149, for then he has all the harvest to himself, and pays nothing, though he has very near the same quantity as if he was subject to the tax. The other is, when near the whole of these 12,000 feet is overflowed by the Nile, but before the water is in contact with the current of the river; for then, though he is liable to pay the meery, he has sown the greatest part of his land possible, without additional labour or expence; more than this is loss, for then the water of the inundation is put likewise in motion, and all the floating pulverised earth that has been trode into an impalpable powder, during March, April, and May, is swept away by the current into the sea, and nothing left but a bare, cold, hard till, which produces little, and is not easily pulverised by the poor instruments of husbandry there in use, when neither farmer nor landholder pays any thing, because, indeed, there is not any receipt.
However, from this uncertainty one thing arises which does not seem to have been understood; for the tenant, not knowing precisely the quantity of seed that he may want, comes to his farm unprovided, and, being uncertain of its produce, takes his land only from year to year; the landlord furnishes him with seed150, and even with all labouring utensils.
And here I am to explain what I have before advanced, what to some will seem a paradox, That the substituting false measures in the Nilometer by the sovereign is absolutely impracticable. Supposing the height of the Nilometer, when at 8 cubits, shewed that there was just corn enough to maintain the inhabitants, and that the tenant knew, by the quantity of land measured, that he had barely what was to pay his rent and support his family; this he must know before he sowed, because he measured immediately after the inundation; and this he must know likewise by the corn he borrows for seed from his landlord, who, as I have said, furnishes his tenant both with seed and labouring utensils. If, then, he finds he can barely maintain himself, and not pay his rent, upon the proclamation at the Nilometer, he deserts his farm, and neither plows nor sows151, but flies to Palestine to the Arabs, or into the cities, and brings famine along with him. The next year there is a plague, and sweeps all those poor wretches, in a bad state of health by living upon bad food, into their graves, so that the introduction, of a supposed false measure, directly advanced by Dr Shaw152, and often alluded to by others, but always without possibility of foundation, is one of the many errors he has fallen into.
He knew nothing but of the Delta, never was in Upper, and no considerable time even in Lower Egypt, but when the Nile had overflowed it, and I suppose never conversed with a fellah, or Egyptian peasant, in his life. All his wonders are in the land of Zoan153, and his observations should have reached no further, because they are not fact, but fanciful imaginations of his own; not from any bad intention, but because he never was in the way of being better informed, but determined not to abandon a system he had once formed.
Herodotus154 mentions, that in the time of Mæris, when, the minimum came to be 8 Samian cubits, all Egypt below Memphis was overflowed, but that in his days it took 16 cubits, or at least 15, to put the same land in like condition for cultivation; or, in other words, the minimum, when they paid their meery, was 16, or at least 15 cubits in his time; and the uncertainty of these two terms shews, that there were unaccountable inequalities, even in his days, as we shall find there have been ever since. But I must here beg leave to ask, why we should believe Herodotus knew the management of the Nilometer more than travellers have done since, as he tells us constantly throughout this part of his history, that when he inquired of the priests concerning the Nile, they would tell him nothing about it155?
In Mæris’s time there were great lakes dug, as Herodotus says156, to carry off the superfluous water, to what place is not said, but surely into the desert for the use of the Arabs. Now, unless we knew what time these lakes were opened to receive the stream, we do not know whether it was the evacuation by the lake, or scarcity of the water that impeded the rise of the Nile upon the Nilometer. We have no account of these transactions, and we shall be less inclined to rely upon them, when I shall shew, that the Nilometer could be of no use in solving this question at all, either in Herodotus’s days, or any time since, without a previous knowledge of several other circumstances never yet taken into the calculation, and of which Herodotus must have been ignorant.
But let us grant that the Nile in Mæris’s time rose only 8 cubits, and in the days of Herodotus to 16, let us see if, at certain periods afterwards, it kept to any thing like that proportion. Above 400 years after Herodotus, Strabo travelled in Egypt; he went through the whole country from Alexandria to beyond Syene and the first cataract; and as he is an historian whose character is established, both for veracity and sagacity, we may receive what he says as unexceptionable evidence, especially as he travelled in such company as it is not probable the priests could have refused him any thing. Now Strabo157 says, that, in his days, 8 cubits were a minimum, or the Wafaa Ullah of the Nile’s increase; therefore, from Mæris’s time to Strabo there is not an inch difference in the minimum, and this includes the space of 1400 years.
It may be said, indeed, that the passage in Strabo158 imports, that, in the time of Petronius, by a particular care of the banks and calishes, the Nile at 8 peeks (or cubits) enabled the Egyptians to pay their meery without hardship; but this was by particular industry, more than what had been in common use, and this, too, I conceive to be Strabo’s meaning. But let us compute from Herodotus, who says that 16, or at least 15, were necessary in his time, whilst Strabo informs us, that, before Petronius exerted himself as to the banks and calishes just mentioned, the extreme abundance must then have been at 12, and the minimum at 10. Now, by this passage, beyond all exception, it is clear that there could have been no increase indicated by the Nilometer; for 10 cubits watered the whole land of Egypt sufficiently in Strabo’s time, whereas 16 and 15 were necessary in the days of Herodotus: and I must likewise observe, that if we should suppose the same industry and attention used in Mæris’s time that was in Petronius’s, (and there is every reason to induce us to think there was) then the proof is positive, that there was no difference in the soil of Egypt indicated by the Nilometer for the first 1400 years.
From this let us descend to Hadrian, about 100 years afterwards. We know from Pliny159, and from an inscription upon a medal of great brass of Hadrian’s, who was himself in Egypt, that 16 cubits were then the fiscal term or rise of the Nile, by which the Egyptians paid their rent; and this is precisely what Herodotus says, in his time, was no more than sufficient.
About the beginning of the 4th century, in the emperor Julian’s reign160, 15 cubits were a sufficient minimum to incur the payment of the tribute, and this is one of the terms that Herodotus fixes upon, as being sufficient to oblige the payment in his days; and the other is 16, or a cubit more; so that if the Nilometer proves any thing at all, it is this, that presumptively the Nile has never increased from Mæris to Petronius’s, or in 1400 years, and certainly that, if it has not diminished, it has not increased for 700 years from Herodotus to the emperor Julian.
Procopius, in his first book, I think, says, that 18 peeks was too full a Nile, and occasioned dearth by its quantity. But, in the middle of the 6th century, he tells161 us it required 18 cubits for a minimum, by which Egypt was to pay the meery; so that in 100 years from Julian to Justinian, the minimum had increased three cubits, which was 4½ feet; not one foot in 100 years as the proposition bears; and this would prove too much, if it was true, but it is impossible.
Thus far, then, we are at liberty to say, that, as long as Egypt was a Greek kingdom, no visible alteration or increase of the soil can be fairly established from history or inspection.
In the 7th century a revolution happened that stops our Grecian account from proceeding farther, Egypt was conquered by an ignorant and barbarous enemy, the Saracen, and Amru Ibn el Aas was governor of Egypt for Omar, the second Caliph after Mahomet. Omar was a foreigner, conqueror, bigot and a tyrant; he destroyed the Grecian Nilometer from motives of religion, the same which had before moved him to burn the library of Alexandria; and after, with the same degree of sound judgment, determined to establish his empire at Medina, in the middle of the peninsula of Arabia, a country without water, and surrounded on all sides with barren sands; but he was nevertheless desirous of feeding his famished Saracens with the wheat of Egypt, a province he had subdued; for this purpose he ordered Amru to begin a canal from the Nile to the Red Sea, to carry the wheat to the Arabian Gulf, and thence to Yambo, the port of Medina on that gulf.
The traitor Greeks, who had delivered the country to the Saracens, had probably informed him of the great plenty which constantly reigned in Egypt, and which every body had an opportunity of knowing by the cheapness of grain at the market.
Omar thought that a larger tribute was due to put the conquerors a little more upon a footing with the conquered; for Egypt, which had once 20,000 cities, had not then the tenth part of them. Having therefore a larger extent to cultivate, with the same quantity of water, it produced more grain, and at the same time having fewer people to eat it, nothing was less oppressive than that a part of the surplus of the produce should go in augmentation of the tribute. For this purpose, following the very weak lights of his own judgment, he introduced a different measure on the Nilometer, and the consequence of that measure, imposed by a conqueror, affected the people (not reflecting upon their decrease in population) so much, that they prepared to fly the country; from which it immediately would have followed, that all Egypt would have lain desolate and uncultivated, and all Arabia been starved.