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States.” With unabated admiration for all that part of geology which is strictly scientific, we devote ourselves particularly to its economical department.

We propose to collect and expose, gratis, to public view, specimens of all the rocks and minerals of the Union which are useful in architecture, agriculture, manufactures, or the mechanic arts, with a view to make them more generally known, and to increase their consumption in this our much favoured land. We desire to open and maintain, with your Institution, a frank and free correspondence, to exchange sentiments upon all subjects connected with our pursuits, and to give and receive, upon the most liberal terms, duplicate geological and mineralogical specimens, and, generally, to co-operate with you in all measures that may tend to increase the mineral wealth and consequent prosperity of our beloved country, or to elevate the mental character of its inhabitants.

With our best wishes for your advancement, we have the honour to be

Your obedient servants,

PETER A. BROWNE, President: M. W. DICKESON, Cor. Secry.

The invitation given in the above letter, was, on motion, accepted.

The following communication, from Mr. Desor, relative to a deposit of drift shells in the cliffs of Sancati Island, of Nantucket, was read, and ordered to be entered in the proceedings :

W. C. REDFIELD, Esq., President of the

American Scientific Association in Philadelphia. DEAR SIR :-In visiting last summer, in company with Lieutenant Davis, U.S. N., the neighbouring islands and shoals of Nantucket, we discovered a most remarkable deposit of Drift Shells in the cliffs of Sancati. These cliffs, which form the eastern boundary of the island of Nantucket, are nearly 100 feet high. The shells are found in two distinct strata, at a height of 30 feet above the cliffs. One of these strata, is a regular oyster bed, 3-4 feet thick, in which not only the oyster, but also the venus, nya, and other bivalves are found in their natural position, both valves together, showing that the animals died in the place in which they lived, and that they have not been disturbed by any violent action, although they have been considerably raised, since there is 50 feet of sand deposite above them, as may be seen in the following section. From the annexed list of species that

have been found, both by my friend Edw. Cabot and by myself, you will perceive that they are the same species that occur near Brooklyn, and also, although in a very broken state, at Point Shirley, near Boston, and that they constitute a thorough littoral fauna, exactly similar to that of the shores of Nantucket and Long Island, actually.

The second stratum in which shells are found rests immediately on the oyster bank, being separated from it in some places by a stratum of serpula that belongs to the oyster bank. This second stratum, one and a half to two feet thick, is quite different in its appearance from the oyster bank below it, although the species that are found in it are the same. The shells are all bleached and more or less worn; the barnacles are disintegrated, and the bivalves have very seldom the two valves united, showing that they have been exposed for a certain time to the action of the waves, before they were buried by the sand layers above them. These sand deposites, like the sand, clay, and gravel strata that underlie the shell strata, are entirely destitute of fossil animals. The only organic remains I discovered was a fragment of wood, in a white sand layer below the oyster bank. At first these strata seem to be horizontal, but Mr. Cabot has since ascertained that they all slip somewhat to the west, their inclination varying from 6° to 15°. At the top of the cliff is found a layer of fine sand, quite irregular in its outline, being formed by the winds that carry the fine particles of sand from the beach to the top of the cliff.

The basis of the cliff is totally different from all the strata mentioned. It consists in a deposite of dark sandy clay, without any distinct stratification in its interior, but its upper surface being very much inclined to the west, and therefore quite unconformable with the sand and shell strata that rest on it. Although no fossil has yet been found in this clay, I feel inclined to consider it as identical with the lower strata of Gayhead, being probably the eastern outcropping of a tertiary basin that underlies the island of Nantucket and Martha's Vineyard, and extends to the north till at Cape Cod. It will be shown in a special paper, on this subject, that this tertiary formation has been deposited in form of a bank or shoal in the ocean of the tertiary epoch, according to the laws of tidal action, that are so satisfactorily pointed out by Lieutenant Davis, the materials of this tertiary shoal being the detritus of the chalk or green sand formation that is found on the shores of the middle States of the Union. Believe me, my dear Sir, yours, most sincerely,

E. DESOR. Boston, 18th Sept., 1848.

Mr. REDFIELD remarked, in relation to the subject of the last communication, that he had found at Brooklyn and on the coast of New Jersey, similar deposites of drift shells.

Prof. Agassiz also submitted some observations in regard to the discoveries of M. Desor.

Messrs. Robert E. and W. B. ROGERS now read a paper, containing the results of investigations on ACIDIMETRY and ALKALIMETRY. [Not received.]

Mr. STEPHEN P. ANDREWS then gave, by chart illustrations and verbal statements, the analogies between the Chinese written and spoken language.

He exhibited the signs and characters used by the Chinese, to distinguish the same words which occur in the English language, as, for instance “wright,” • right,” • write,” &c. The word “ting,in the former language, indicates the same sound, and, by an additional affix or prefix, the intelligence meant is conveyed.

Prof. JOHNSON communicated the following report, by J.H. ALEXANDER, Esq., on Geographical Explorations during the year 1847 and a part of 1848. The paper is entitled



1. Africa.

The most important exploration actually going on in this continent, is that of Mr. ANNE RAFFENEL ; both as regards the amplitude of design, the aids and connexions under which it is being prosecuted, and the probable fitness of the individual explorer himself. Prepared for the undertaking by special preliminary studies and exercises, and having already approved himself by the experience of travel in 1844, in Upper Senegambia, he takes with him now the necessary apparatus for scientific researches, instructions from the Academy of Sciences and the Geographical Society of France, and funds supplied, in part at least, by the French Government. How far the recent changes in that government will affect this last particular, and alter the semiofficial aspect, which his mission wears, is not yet known. The original design is no less than to cross the entire continent, in general along the 15th parallel of N. lat. In fact, ascending the Senegal, his course would take him into the valley of the Jolibah, by Sego and Timbuctoo (at the former of which places he most probably winter

ed), through Central Soudan. The Quorra, in part, the Yeon, and then some eastern tributary of Lake Tchad, are supposed to point and facilitate the route through to Darfur and Kordofan ; whose yet unknown territories once passed bring the traveller to the comparatively friendly waters of Nile. Not the extent of the journey only—though from Cape Verd, for instance, to Shendy, on the Nile, is, along the parallel, nearly four thousand miles, while the actual track will be much longer — but the perils and difficulties, physical, moral and spiritual, which environ and beset every inch of the way, from Sego to the Nile, constitute the draw back to this superb design ; whose execution will leave the achievements of preceding travellers, on that continent (already watered with blood as high as ever flowed in manly veins) quite in the shade, and will solve one of the great problems of North African geography.

Connected with this exploration of Soudan, may be mentioned the publication, in 1847, by Dr. Rosen, interpreter attached to the Prussian Legation at Constantinople, of a German translation from the Turkish Narrative of a Journey made about 1800, in the negro kingdom of Daz-Zaleh or Wadai (between Begharmi and Darfur, in the easternmost part of Soudan or Nigritia), by Scheich Zaïn el Abidin, a Mohammedan of Tunis. The original narrative in Arabic has not come to the hands of Dr. Rosen. It is much to be desired that some traveller in Tunis would make research to recover the text. The territory of Wadai is in Mr. Raffenel's route ; but, except some vague information of Brenne, Seetzen and Burckhardt, it was before Dr. Rosen's publication quite unknown to Europeans. It is true, that there exists in MS., and in the hands of Mr. Jomard (who caused to be published, in 1845, a French translation of the part relating to Darfur), the narrative, more recent, of another Tunisian, Scheich Mohammed el Tounsi, who also travelled in Wadai. This may be expected to be published ; and although, from the religion and education of both travellers, not many important additions to our knowledge are to be looked for, still it would be both piquant and instructive to read and compare these two accounts in advance of the more important and reliable one which we may hope is reserved for Mr. Raffenel to afford.

It is reported, very recently, that, under the stimulus of this publication of Dr. Rosen, the King of Prussia is about to send a scientific commission to explore the architectural remains signalized by El Abidin. It is probable, however, that the present unsettled state of European affairs will contribute to retard this desirable measure.

In conclusion of the subject of Nigritia, may be mentioned the recent publication under the sanction of the British Colonial office, and of the Admiralty, by Messrs. Allen and Thomson, of the Narrative of the Expedition to the Niger, in 1841, under Captain Trotter.

On the eastern coast of the continent, an exploration is going on under the auspices of the East India Company, and in charge of Mr. Parker, one of their marine, to ascend the Jub, a river of Zanguebar, falling into the Indian ocean, about the latitude of the equator. Should this prove to be identical with the Godjeb, part of whose course only is known, there would be opened an easy communication with the southern part of Abyssinia ; a route of high importance in a commercial point of view, but which, although it has furnished, since a long time, plausible grounds of entertainment, was never seriously taken up until a few years ago, by the lamented missionary, Krapff. The current of recent investigations, however, it must be said, is against the identity mentioned ; and Dr. Behe, one of the first to assert it, is now, upon the results of the exploring expeditions, sent by the Viceroy of Egypt, inclined to regard the Godjeb as one with the Telfi or Sobat, a confluent of the Bahr-elAbiadh or White Nile. But it does not follow, even upon this, that the route contemplated may not be substantially obtained.

Another traveller, Mr. Leigh, has been sent, by a London company, to Quiloa, on the Zanguebar coast, more south ; in order to penetrate by the Mozimba or some other stream, westward, to the great Lake N’Yassi, the Maravi or Zambezi, of our older maps. Apart from the commercial importance of success in this exploration, it has, just now, an additional scientific interest, in connexion with the opinion advanced by one of the best informed and most competent Abyssinian travellers-Dr. Behe, just mentioned—that this Lake Marair is the true head of the Nile.

The annunciation of this opinion, to be sure, has been followed by an expression of dissent, on the part of another distinguished traveller, if he is not rather to be called a resident in Abyssinia, Mr. d’Abbadie, whose grievous silence, protracted through nearly two years, had given rise to most sorrowful forebodings. Far from allowing to the Nile such an extension as would cause its source to be found south of the equator, Mr. d'Abbadie supposes its real fountain to be that of the Gibé in Jwarya (about 7° 49' N. lat.), whence, with a semi-circular sweep under various names of Omo and Uma and Bagno, it makes a Chersonèse of the territory of Kaffa. The developments of our ordinary maps do not allow this course to be traced with intelligible

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