now attained its utmost limits as to superficial extent, and that while in ancient times when the bulk of water was much greater than at present, it was able to overcome the slender barriers presented by the loose soil which formed its coasts; in the present day its diminished depth and increased surface have added so much to the rapidity of its evaporation as to cause it to recede from its former conquests. Our Russian engineer must therefore wait. But we are digressing; we forget that Herodotus is the historian of the Persian war, not the Russian.

No country seems to have possessed such attractions for our traveller as Egypt. The peculiarity of its formation, its magnificent monuments, the enormous wealth of its government, the fabulous antiquity of its history,-all combined to render it a most interesting object of research. He visited it in person, and took the utmost pains to make himself acquainted with its religion, history, geology, architecture, national and social peculiarities, and its industrial resources. Nothing was left unexplored. The minutest subject claims his attention as well as the greatest, the most abstruse as well as the most familiar. His researches into the age and construction of the Pyramids do not cause him to abridge his account of the natural history of the crocodile. He is neither afraid to discuss the probable age of the valley of the Nile, nor ashamed to tell us which is the most piquant and scientific way of cooking the byblus. How can Major Rennell say that "as a man of science and a natural philosopher, he ranks very low indeed," and that only history and morals are his strong points? Look at the thoroughly scientific way in which he commenced his researches. At one day's sail from the mouths of the Nile, he tells us, they cast the lead in eleven fathoms of water, and found that the bottom consisted of alluvial mud. The greatest number of miles accomplished in one day by a vessel was one hundred and sixty miles, but the average daily rate of sailing was not more than thirty-eight. The former of those distances is obviously inconsistent with Herodotus's calculation of the depth of water, but the latter may have been tolerably correct. Two thousand years later, Shaw found black mud at a distance of sixty miles out at sea-an observation that would seem to confirm the substantial accuracy of Herodotus' statement. But, with our traveller, this was no idle experiment: it was intended to supply him with the first fact in a series of inductions by which he hoped to ascertain the nature of the country and the manner of its formation. The existence of mud at so great a distance from the shore led him to attribute the formation to its true cause, namely the alluvial deposit made by the Nile; and the fact seems to have given him a clue for * Geography of Herodotus, p. 6.

the prosecution of his speculations regarding the general formation of the country.

After describing, with considerable accuracy, the extent and general appearance of Egypt from the coast to Heliopolis and thence to Elephantine,-almost all his measurements having been verified and found wonderfully correct, he proceeds to give his opinion as to the way in which the whole of that space had been formed. He considered that the original line of coast lay in the same parallel with the position then occupied by Memphis, and that a gulf of the sea ran southwards in the present valley of the Nile between the Arabian mountains on the one side and the Libyan on the other. He does not say positively to what length he believed this gulf to extend, but he appears to have thought that it ran parallel with the Red sea and terminated near the point where that sea debouches into the Indian ocean. He supposed also that the average width of this gulf was about the same as that of the Red sea, which he computes at half a day's sail at its widest part,-a calculation much below the truth, unless it be intended for the western arm called the sea of Suez. But how came this long and deep gulf to be filled up with the rich alluvial deposit which Herodotus found teeming with inhabitants and constituting the wealth and prosperity of the country? "Nothing easier," says our historian, looking back with the utmost coolness and simplicity through vast periods of time which would stagger any but the practised geological reader. Suppose," says he, "the Nile were to turn its stream into this Arabian gulf, what is to hinder the sediment which it would deposit from filling up the whole space in the twenty thousand years: nay I think it might be done in ten thousand years." Very possibly, as we hope to shew in the sequel in the meantime we must stop to remark that this speculation, however ingenious, involves, as one may see by a glance at the map, a somewhat erroneous view of the relative positions of the Nile and the Red sea; for the entrance into that sea is in the same parallel with Gondar in Abyssinia, and if the Gulf which Herodotus imagined to run up from the Mediterranean extended to that parallel, the dimensions of the Nile would be so much abridged as to render its filling up so large a tract of country highly improbable. But Herodotus was not a man to be satisfied with a speculation. He must have positive evidence, if attainable, before he could thoroughly make up his mind. Accordingly he continues his researches regarding the formation of the country to see whether the facts of the case bear out his conclusion. One important fact he discovers is that the coast of Egypt projects considerably further into the sea than the adjoining portions of country on each side; and he naturally enough attributes this projection to the existence of some pro

pelling power higher up the country not possessed by the neighbouring lands. And what could this be but the Nile? The lower country must also at some former period have been covered by the sea, for numerous sea-shells were found lying about on the mountains, and a saline crust had formed on the rocks and ancient monuments. Land also was found in abundance on a mountain just above Memphis, implying that the sea had extended as far as to that point inland. An additional argument was deduced from the difference between the soil of Egypt and those of the adjacent countries, Syria and Libya,-that of the former country being black and crumbling, while the soils on either hand were, towards Syria, argillaceous and flinty, towards Libya, red and sandy.

Herodotus' opinion that the formation of Egypt is to be attributed entirely to a cause which had been working uniformly for ages and was still at work when he visited the country, was confirmed by information supplied him by the priests that in the time of king Maris,-which he computes to have been nine hundred years previous to his own time-the whole surface of Lower Egypt was inundated when the Nile rose eight cubits; whereas, when Herodotus was in Egypt, the lands were not overflowed unless the Nile rose fifteen or sixteen cubits. The elevation of the land in the immediate vicinity of the Nile must therefore, he computes, have been increased by seven or eight cubits, that is, ten or twelve feet within a space of nine hundred years. It is probable that the historian is wrong in calculating the interval between his own time and that of Maris to be only nine hundred years; modern chronologers reckon it to be about fifteen hundred years; but even that extended period will not account for so great a rise in the surface of the country. Four inches in a century is the rate of deposit in the neighbourhood of Cairo as established by data obtained within the last nine hundred years; and if the process had been going on at a uniform rate, the deposit of eight cubits of alluvial soil would represent a period of not less than thirty-six centuries. The erection of dams and construction of canals would tend to diminish the rate of deposit in later times, but even this qualification will not warrant our allowing a less period than three thousand years for the increased elevation of the country which the priests informed Herodotus had taken place since the time of Maris. But this period is quite within the reach of traditional record, and we are therefore not inclined to disbelieve that the statement of the priests did actually represent what the original surface of the country had been according to their traditional authorities. We may consider this statement, then, as being the earliest geographical information which we possess concerning Egypt. The real

history of its alluvion, indeed, goes back far beyond that period, for geographers tell us that the present base of the rock on which the pyramids of Memphis stand, is seventy or eighty feet above the level of the base which was originally washed by the sea,-a deposit which, at the present rate, could not be formed in a less period than two hundred and ten centuries. But Herodotus does not pretend to have obtained historical or traditional information regarding any period of such high antiquity. His calculation of the time in which the Red sea would have been filled up by a river similar to the Nile, does not profess to have any other basis than speculation. It may however be worth remarking that the two hundred centuries which he allows for the completion of this work agrees very nearly with the actual age of the Nile's alluvion in the neighbourhood of Memphis. We shall not attempt to decide whether this coincidence is designed or not.

Herodotus' speculation about the causes of the Nile's periodical rise, though erroneous, is exceedingly interesting, and at the same time so suggestive of the state of philosophical enquiry among the Greeks of his time that we are tempted to refer to it at length. We cannot do better than extract Dr. Whewell's account, in his History of the Inductive Sciences, of these early attempts at scientific investigation.

"Concerning the nature of this river,' says the father of history, 'I was not able to learn anything, either from the priests, or from any one besides, though I questioned them very pressingly. For the Nile is flooded for a hundred days, beginning with the summer's solstice; and after this time it diminishes, and is, during the whole winter, very small. And on this head I was not able to obtain anything satisfactory from any one of the Egyptians, when I asked what is the power by which the Nile is in its nature the reverse of other rivers.'

"We may see, I think, in the historian's account, that the Grecian mind felt a craving to discover the reasons of things which other nations did not feel. The Egyptians, it appears, had no theory, and felt the want of none. Not so the Greeks; they had their reasons to render, though they were not such as satisfied Herodotus. 'Some of the Greeks,' he says, 'who wished to be considered great philosophers, have propounded three ways, of accounting for these floods, two of them, he adds, 'I do not think worthy of record, except just so far as to mention them.' But as these are some of the earliest Greek essays in physical philosophy, it will be worth while, even at this day, to preserve the brief notice he has given of them, and his own reasonings upon the same subject. One of these opinions holds that the Etesian wind, (which blew from the north) are the cause of these floods, by preventing the Nile from flowing into the sea.' Against this the historian reasons very simply and sensibly. Very often when the Etesian winds do not blow, the Nile is flooded nevertheless. And moreover, if the Etesian winds were the cause, all

other rivers, which have their course opposite to these winds, ought to undergo the same changes as the Nile; which the rivers of Syria and Libya so circumstanced do not.'

6

“The next opinion is still more unscientific, and is in truth, marvellous for its folly. This holds that the ocean flows all round the earth, and that the Nile comes out of the ocean, and by that means produces its effects. 'Now,' says the historian, the man who talks about this ocean river, goes into the region of fable, where it is not easy to demonstrate that he is wrong. I know of no such river. But I suppose that Homer or some of the earliest poets invented this fiction and introduced it into their poetry.'

6

"He then proceeds to a third account, which to a modern reasoner would appear not at all unphilosophical in itself, but which he, nevertheless, rejects in a manner no less decided than the others. The third opinion, though much the most plausible, is still more wrong than the others; for it asserts an impossibility, namely, that the Nile proceeds from the melting of the snow. Now the Nile flows out of Libya and through Ethiopia, which are very hot countries, and thus comes into Egypt which is a colder region. How then can it proceed from snow ?' He then offers several other reasons to shew,' as he says, 'to any one capable of reasoning on such subjects, that the assertion cannot be true. The winds which blow from the southern regions are hot; the inhabitants are black; the swallows and kites stay in the country the whole year; the cranes fly the colds of Scythia, and seek their warm winter quarters there; which would not be if it snowed ever so little.' He adds another reason founded apparently upon some limited empirical maxim of weather-wisdom taken from the climate of Greece. Libya,' he says, 'has neither rain nor ice, and therefore no snow; for in five days after a fall of snow, there must be a fall of rain; so that if it snowed in those regions, it must rain too.' I need not observe that Herodotus was not aware of the difference between the climate of high mountains and plains in a torrid region; but it is impossible not to be struck both with the activity and the coherency of thought displayed by the Greek mind in this primitive physical enquiry.

But I must not omit the hypothesis which Herodotus himself proposes, after rejecting those which have been already given. It does not appear to me easy to catch his exact meaning, but the statement will still be curious. 6 'If,' he says, 'one who has condemned opinions previously promulgated may put forward his own opinions concerning so obscure a matter, I will state why it seems to me that the Nile is flooded in summer.' This opinion he propounds at first with an oracular brevity, which it is difficult to suppose that he did not intend to be impressive. In winter the sun is carried by the seasons away from its former course,* and goes to the upper parts of Libya. And

* We are afraid there is no authority for this rendering. Herodotus describes the sun as being driven towards the south in the winter by storms. Dr. Whewell's anxiety to "let" Herodotus "down" as gently as possible has led him into this inaccuracy. The historian's ideas of the sun's position and course are suffici ently proved to have been erroneous by his remarks on the African Periplus and the solar phenomena of India.