low the level of the Nile, and admits of being irrigated. The extent may be estimated roughly at twenty-seven miles by six, or 103,680 acres. And if the Nile was admitted pretty freely to flood it for several years, and afterwards more sparingly, for the purpose of irrigation, it is reasonable, that, with the slime and water which could thus be supplied, the tract might become highly valuable for tillage; and when the soil became fixed with a fruitful vegetation, it would be easy and useful to prolong the canal of the Long Valley or Wadis upon a uniform level through the distance occupied by the basin of the Bitter Lake, as a canal of irrigation, which might also serve for navigation to the small craft of the Nile to the vicinity of Suez, where, by means of locks, it might be connected with the great canal of salt water proposed between the two

seas.

Whichever line be adopted to form a ship navigation between the two seas, the cost would not be far short of two millions sterling; and it is pretty clear, with such an expected outlay, neither states, rulers, nor companies would venture on the undertaking without some sufficient guarantee that the cost would be indemnified by the profits of the undertaking. Unfortunately, at present, it is not easy even to form an approximate estimate of the commerce that would pass through the channel; but, converting the Red Sea into a strait, or open channel, as this measure would do, it is obvious that this new passage would connect the whole shore of the Mediterranean with the east coast of Africa, and with the shores and islands of Asia, by a new route, and open a common highway of commerce between a greater extent of coasts than any other channel on the face of the globe.

In the years 1832 and 1833, the average tonnage from and to Great Britain with all places eastward of the Cape of Good Hope, amounted to 285,000 tons; and if we assume that the whole traffic of Europe, including that of Great Britain, passing through the Suez canal, would be three times the above quantity, we should probably be under the truth; and that assumption would give 855,000 tons annually, or about onehalf of the tonnage passing the straits of Dover and Calais.

It must however be obvious, that, in opening a navigation so much shorter than the old one, and which consequently might be performed in much smaller vessels with less costly equipments, a great impulse would be given to trade in the new direction; and that entire new sources of commerce would be opened between the places adjacent to each extremity of the Red Sea, but which could not, under present circumstances, be attempted with any hopes of success from the length of voyage involved; and, with these considerations, it will not be deemed unreasonable to expect, that the commerce passing through the canal annually, would, in a short time, amount to one million tons, and might eventually reach two millions of tons; but restricting the estimate to one million tons, the following result would be obtained :—

So that, whatever greater traffic might arise, or whatever higher rate of duty it might be deemed prudent to exact, would operate as a bonus on the interest of 5 per cent.

Again, the official value of the exports and imports from and to Great Britain, with places eastward of the Cape, in the year 1828, amounted to sixteen millions sterling; and if we assume this as a third part of the amount of the imports and exports of all nations passing annually through the canal of Suez, we obtain forty-eight millions value on the amount : and taking the points into consideration stated in respect to the tonnage, we may estimate the annual value in round numbers at fifty millions sterling, the duty on which at per cent. would yield a revenue of L.125,000 per annum.

A good deal is alleged by those trading from Britain to the East Indies against the policy of any part of the British nation lending patronage to such an undertaking, which, it is presumed, would benefit the countries bordering the Mediterranean more than our own; though, if the canal in question would be the means of most materially shortening the distance between the two most important portions of the British Empire, little doubt can be entertained of the benefit conferred on the extensive commerce of the two countries, even though some other nations would receive a greater proportional advantage in the accomplishment of the measure; and though the commerce of other nations might increase in a greater ratio than the British, still all would participate in facilities to be obtained; and in the case of war arising, it is but too obvious, that the power possessing a naval superiority has the means of closing such a channel of commerce to its enemies, by stationing cruisers at each extremity. So much may be urged with a view of removing the prejudice of British interests against the measure; but it will readily be believed, that if the British fail to patronize the undertaking, other nations and powers will do so shortly: and it is therefore manifest, if British subjects were chiefly concerned in advancing the capital, and in executing and managing this great work, it would be vastly more for the benefit of Britain, than if any other nation or government lent their resources. But, undertake it who may, it is most probable that both the funds and the energies of execution will come from this country; and it is too probable, that if the measure is executed by any other parties than British, the work will be upon a cheaper and less effective plan of navigation, permitting only small craft to navigate, unfit for British commerce in the East, though sufficient for small traders in the Medi

terranean, who would consequently, in such a case, reap the entire benefit. I am decidedly of opinion, that British capital and British energy would alone execute the work in a truly useful and permanent style. But the measure is daily becoming so much more obvious as one of practical facility, that it cannot long be postponed in some shape or another.

The conclusions may now be recapitulated in general terms :—

1st, That a ship canal between the two seas, which contemplates an extended commerce between the countries of Europe' and the Indian Ocean, should be free from the effects of all fluctuating causes, arising from inundations or floods, &c.

2d, That it should be a measure irrespective of the commerce of Egypt and the Nile, or rather that it could not combine these objects in the same measure with any good results; though it would be the means of greatly improving the commerce of Egypt by accessory measures.

3d, That the mean fall from the level of the Red Sea to that of the Mediterranean (say 30 feet) is sufficient to keep the artificial channel clean, if the fall be properly economized; and also that it would be able to preserve its mouth in the Bay of Pelusium in a navigable state at all

seasons.

4th, That a navigation of still water with locks could not be long maintained with advantage, under all the circumstances of the case.

5th, That a broad and deep stream, like that of the Dardanelles, could not be produced by natural operations, assisted slightly by art; but that the attempt would be pregnant with mischief in some quarters, and result in disappointment.

6th, That a direct and perfectly controllable channel of a uniform size and shape and incline, would be the safest and most appropriate undertaking of which the circumstances permit, and under the imperfect information we possess.

It must, however, be confessed, that no definitive opinion can be given, or very satisfactory estimates assumed, until a new and detailed survey, having the express objects in view, is completed, comprehending the necessary levellings and borings and maritime surveys of the ports at the termini of the canal.

With respect to the land survey, were all the necessary persons and means duly prepared to commence operations in the beginning of October, it is probable the investigation might be completed in the beginning of the following May, and a true solution given to this great geographical, commercial, and engineering question.

As mankind multiply and make progress in the arts and civilization, new wants arise, and the ingenuity and industry of man is taxed to discover new sources of wealth, maintenance, and occupation; and we find, under the dispensations of an allwise Providence, that at suitable seasons resources are unveiled which have been long provided but con

cealed until the fit occasion presents itself. Amongst the numerous administrations of the same wise and merciful design, it is not unreasonable to believe that the completion of navigable channels across the isthmuses of Suez and Darien are enterprizes amongst the events designed to minister to the growing wants and improvement of the human race.

Report of the Researches of M. Agassiz during his last two sojourns at l'Hotel-des-Neuchâtelois, upon the Lower Glacier of the Aar, in the years 1841 and 1842. By M. E. DESOR.

(Concluded from Vol. xxxv., p. 313.)

Observations upon the Composition of Ice.-Observations upon the composition of ice had been demanded from all quarters, on account of the intrinsic importance of this subject, and on account of the very contradictory opinions which had been published regarding it. Accordingly, when we returned to the glacier of the Aar, in the year 1842, we took along with us a complete armamentarium of tubes, probes, weights, balances, and other apparatus of this kind; and M. Nicolet, in concert with M. Vogt, undertook the conduct of these observations. A kind of laboratory was constructed for the purpose, near our hut, to the north of it; and the day after our arrival M. Nicolet commenced operations.*

From the observations so made, it follows that the blue ice really contains the smallest quantity of air. It is true that the ice taken from the Gallery did not contain much more; but it ought to be remembered that there the entire mass of the glacier is as it were transformed into blue ice. Lastly, the white ice, which owes its dull appearance to the numerous air-bubbles it encloses, contains much more air than the blue ice. M. Hugi, as may be known to many of our readers, had previously discovered that, when ice is put into an enclosed bell-jar, supplied with a tube which is plunged into a mercurial trough, the mercury ascends in the tube during the course of the night, and descends again during the day; and from

* For an account of these Experiments, see Jameson's Journal, vol. xxxiii., p. 401.