the south) it gradually loses its decided character, and at the limit all trace of a fixed direction disappears, the current at any place being controlled entirely by local influences. This he illustrated by a separate diagram of the winds at Augusta, Georgia. After passing this limit on the south, he showed that a current from the opposite direction sets in, which, as we go south, gradually assumed a more decided character till we come fully within the limits of the trade winds. He alluded, in passing, to a peculiarity in the winds west of the Mississippi, between lat. 30° and lat. 40°, as explaining the tracks of storms in those regions.

North of latitude 60° he showed that there are indications that the strong current that comes down from the north in the polar regions veers toward the west; thus establishing a third system, which breaks up about at latitude 60°. The observations taken at various places in Russia and British America, Norway and St. Petersburg in Russia, were alluded to as indicating this fact.

After having gone through with his remarks upon the general course of the winds, he took up the subject of the annual curve which they describe, and showed that while on the eastern coast of Asia it is the same as here, in Europe the curvature seems to be in the opposite direction-also that a curvature physically similar exists in both the easterly and westerly systems of winds.

He next spoke of the relative force of the different winds, showing how far the general results are modified from this cause.

After remarking that he was compelled for want of time to omit several matters embraced in the report, he closed with an expression of thanks to the numerous friends who had aided him in obtaining the necessary data, and whom he mentioned by name, with the kind of aid received from each.

LT. M. F. MAURY, U.S.N., on the Winds and Currents of the Ocean.Lt. MAURY reminded the Association that in 1844, they appointed a committee to represent to the Secretary of the Navy, the importance of the services which our armed cruisers might render to the cause of science, by a systematic series of observations upon the currents, temperature and other phenomena of the sea. Judge Mason was a man of enlarged mind and liberal views; he received the representations of the committee as a friend of science and a statesman should do.

It was owing to the impulse thus given, that Lt. Maury had been enabled to carry out a plan which he had long entertained, of constructing a series of charts which should give to each navigator the benefit of the combined experience of all who had gone before him, as to the winds and currents in every part of the ocean. Charts upon this plan, of the North Atlantic, were exhibited before the Association.

They are so constructed as to shew at a glance the prevailing winds, currents, temperatures, &c. for every month in all parts of the ocean. The characters or symbols for the winds are so contrived, that they shew at once both the direction and strength of the wind.

To obtain the results exhibited before the Association, involved immense labor: many thousand old log-books had been overhauled, and the records of each as to winds, temperature of the sea, variation of

the compass, and force and set of currents, compared with all the rest: but the results were of high interest and great value. They shew that the trade winds in the North Atlantic blow with much more regularity on the American, than on the African side of the Atlantic, owing to the fact that in the latter case the sands and deserts which heat and rarefy the air, are to windward; while in the former, they are to leeward. It was also shewn that the trade winds prevail more from the northward on the American, than they do on the African side; and that calms are much less frequent on this, than on that side of the ocean.

By an ingenious manner of discussing the records with regard to winds, Lt. Maury has been led to the discovery of a region near the equator, and extending midway the Atlantic from the shores of Africa, in which, instead of a northeast trade-wind, as there is between the same parallels in other parts of the ocean, there are regular southeast and southwest monsoons.

He pointed out the usual route of vessels bound across the equator from the United States, and shewed that it is over towards the coast of Africa, near the Canary and Cape de Verde islands. It lies through this anomalous region, which it is difficult to cross under sail, owing to the fact that the winds there are mostly head winds. This circumstance led Lt. Maury to the discovery of a shorter route to the Equator through a region of better winds. He had made known this new route to navigators. He had received the returns of seven who had tried it; and the average length of their voyage to the equator was ELEVEN days less than the average by the usual route.

The manner in which his charts were cut up by the tracks of vessels, enabled him to speak confidently as to the existence of a number of vigias and other dangers of doubtful position, which disfigure our best and most accurate general charts. Many of these, he pronounced to have no real existence. He is preparing a list of such as may be erased from the charts of the North Atlantic.

Many curious and interesting facts were exhibited concerning the temperature of the ocean. Among these, Lt. Maury pointed out, off the shores of South America, between the parallels of 35° and 40° S., a region of storms, and of ocean temperature as high as that of our own Gulf Stream, whereas in the middle of the ocean and between the same parallels, the temperature of the water was not so great by 22°, and storms by no means so frequent.

Lt. Maury lamented the neglect of the thermometer-a most useful little instrument-among navigators generally. New York, he said, owed her commercial supremacy in a great degree to the water-thermometer. Up to the time when Dr. Franklin with this instrument discovered the Gulf Stream, Charleston had more foreign trade than New York and all the New England states together. Charleston then was the half-way house between them and Europe. When a vessel, attempting to enter the Delaware or Sandy Hook, met a northwest gale or snow storm, instead of running off a few hours into the Gulf Stream, to thaw and get refreshed by the genial warmth of its waters, as she now does, she put off for Charleston or the West Indies, and there remained till the return of spring before making another attempt.

New York now has more direct trade in a week than Charleston has in a year. Perhaps Dr. Franklin with his water-thermometer, and Jer. emiah Thompson & Co. with their packet-ships, may be regarded as the two most powerful agents of the many concerned in this revolution. The frequent and general use of the water-thermometer by naviga tors, is the only means by which we can arrive at a proper knowledge of the aqueous circulation of the globe, of the currents and isothermal lines of the ocean.

The Secretary of the Navy has authorized copies of these charts to be given to every navigator who would return to the National Observa. tory, according to form, an abstract of his voyage. Several thousand sheets of the chart have already been distributed upon these terms, and there are now engaged upon all parts of the ocean, hundreds of vessels making and recording observations for this work. Never before was such a corps of observers known. The commercial marine of no country can boast of more accomplished navigators than those of the United States.

The importance of simultaneous observations in all parts of the ocean, was dwelt upon with much earnestness. The field is as wide as the ocean, and there is room in it yet for multitudes of laborers. The work is not exclusively for the benefit of any one nation or age, and it was suggested whether the states of Christendom might not be induced to cooperate by their navies in the undertaking.

The next annual meeting of this Association, stands adjourned to Cambridge, Mass., on the 2d Tuesday (14th) of August, 1849. President, JOSEPH HENRY; Secretary, Dr. JEFFRIES WYMAN. The auspicious character of the Philadelphia meeting-the great interest it has excited in the minds of those who were presentthe advantages offered by Cambridge to draw together men of science-all contribute to support the opinion that much may be expected of the session of 1849. In the matter of publication, the Association have ordered the Secretaries of the Sections, and the general Secretary, to prepare a full report of all the papers read before their several meetings, and to submit them to a Publishing Committee, who are charged with the issue of a volume of proceedings. No abstracts of papers read, or remarks made before the sections, will be published, unless the same have been furnished or approved by the authors. It is hoped that another year may enable the Association to publish a volume with full memoirs and reports, as well as abstracts. For this purpose, a

much more general enrollment of members will be necessary. The present session of the Association lasted five days, during which time, three daily sessions were held, in the halls of the University of Pennsylvania on Ninth street.

SECOND SERIES, Vol. VI, No. 18.-Nov., 1848.

52

ART. XXXVIII.-Report on Meteorites; by CHARLES UPHAM SHEPARD, M.D.

[Read before the American Association for the Promotion of Science, at Philadelphia, Sept. 20, 1848.]

HAVING Completed the description of the meteoric iron-masses of the United States, it now remains to describe the American meteoric stones. As a result of new observations respecting these bodies generally, it becomes necessary to propose a slight modification of the classification previously adopted.

The localities to be described under the above classification, with the dates of fall, &c., are as follows:

CLASS II.

Order 1st.

1. Linn Co., Iowa.

Section 1st. Fine grained.
Fell Feb. 25th, 1847, 2h. 50m. P.M.
Weight about 75 lbs.

De

scribed by SHEPARD. 2. Castine, Maine. Weight 12 oz.

ARD.

Fell May 20, 1848. Described by SHEP

3. Nanjemoy, Maryland. Fell Feb. 10, 1825. CARVER and CHILTON. Weight about 16 lbs.

Described by

4. Sumner Co., Tennessee. Fell May 9, 1827. Described by SEYBERT. Weight 11 lbs.

5. Forsyth, Georgia. Fell May 8, 1829. Described by SILLIMAN, Sen., and SHEPARD. Weight about 36 lbs.

6. Nobleboro, Maine. Fell Aug. 7, 1823. Weight about 5 lbs.

CLEAVELAND and WEBSTER.

Described by

7. Little Piney, Missouri. Fell Feb. 13, 1839. Described by HERRICK and SHEPARD. Weight about 50 lbs.

Section 2d. Coarse grained.

8. Weston, Connecticut. Fell Dec. 14, 1807. Described by SILLIMAN, Sen., and KINGSLEY. Weight about 300 lbs.

9. Richmond, Virginia. Fell June 4, 1828. Described by SHEPARD. Weight 4 lbs.

Order 2d.

10. Bishopsville, South Carolina. Fell March, 1843. Described by SHEPARD. Weight 13 lbs.

APPENDIX.

a. Waterville, Maine. Fell March, 1843. SHEPARD. Weight about 3 oz.

Described by

b. Concord, New Hampshire. Fell Oct., 1846. Described by SILLIMAN, Jr. Weight 370 grs.

Before treating of these different localities, it must be observed, that the ingredient of meteoric stones called olivinite in the preceding report, will hereafter be spoken of as olivinoid; since reasons of sufficient weight have presented themselves, in the examination of the substance in question, to authorize its separation from the common volcanic mineral (as well as from the transparent crystals and grains contained in the Siberian and the Atacama meteoric irons). The olivinoid has a hardness equal only to 5.5....6; while olivine is from 6.5....7. The former turns black, and fuses easily before the blowpipe; while the latter grows pale and is infusible. Olivinoid is more easily attacked by the acids than olivine: moreover, it seems most probable, from what is at present known of its composition, that the olivinoid is throughout, a bisilicate, and not a simple silicate.

I have distinguished another equally abundant earthy mineral in meteoric stones as new, under the name of howardite, which was detected in consequence of its existing in an almost perfectly insulated state in the Iowa stone. This will be described under the account now to be given of that meteorite.

1. Linn Co., Iowa.

I have given the principal facts attending the fall of stones at this locality, in the Amer. Journ. of Science, ii ser., Vol. iv, p. 288. It is only requisite to add, that the small stone seen to fall, was picked up on the land of Mr. Daniel C. Rogers, situated on section 21, township 82 north, range 6 west. The larger portion of the fallen meteor was found in section 20, from a mile to a mile and a half, west. This consisted of two masses and not as first supposed, of the fragments of a single