This immersion of Sagittarii was observed, Aug. 22d, 1836, as follows: h m 8 By R. T. Paine, at 10 14 57.46 at Mansion House, Northampton. By W. C. Bond, at 10 23 20.90 at his Observatory. By S. C. Walker, at 10 1 7.30 at N. 4.4", W. 1.06s of S. House, Ph. Again, for the longitude of Brown University, Providence, Mr. Paine finds, Boston-Providence, 1 1 22.64 by 40 chronometers. 22.29 by eclipse of May 15th, 1836. Mr. Paine's observations of the eclipse of Sep. 18th have already been reported. Those for latitude and regulation of chronometers have been stated more at length, in order to furnish examples of the method pursued by that gentleman in the chronometric survey of Massachusetts, the only work of the kind of much extent hitherto performed in this country. Some idea of the labours of Mr. Paine may be formed from the fact, that, during its progress, he has been under the necessity of making and reducing more than 100,000 observations of altitudes of the sun and stars, without any assistance. It is proper to add that Mr. Gilliss' observations, already reported, appear to require a subtractive correction of 1.958. Thus Mr. Paine's observations give, Sep. 18th, 21 25, Barraud 151 fast by its own rate + 19 20.80 by comparison with 682 Barraud, 20.91 Professor Henry read a paper entitled "Contributions to Electricity and Magnetism, No. 3. On the Phenomena of Electro-dynamic Induction." Referred to Prof. A. D. Bache, Dr. Patterson, and Dr. Hare. The primary object of the investigation undertaken by the author, was the discovery of induced currents from ordinary electricity, similar to those produced by galvanism. Preparatory to this, a new investigation was instituted of the phenomena of galvanic induction, and the result of this forms, perhaps, the most important part of the communication. The first section of the paper refers to the conditions which influ ence the induction of a current on itself, as in the case of a long wire and a spiral conductor. These are shown to depend on the intensity and quantity of the battery current, and on the length, thickness, and form of the conductor. The next section examines the conditions necessary to the production of powerful secondary currents, and also the changes which take place in the same, when the form of the battery, and the size and form of the conductor are varied. The important fact is shown, that not only a current of intensity can be induced by one of quantity, but also the converse, that a current of quantity can be produced by one of intensity. The third section relates to the effect of interposing different substances between the conductor which transmits the current from the battery, and that which is arranged to receive the induced current. All good conducting substances are found to screen the inducing action, and this screening effect is shown, by the detail of a variety of experiments, to be the result of the neutralizing action of a current, induced in the interposed body. This neutralizing current is separately examined, and its direction found to be the same as that of the battery current. The question is then raised, how two currents in the same direction can counteract each other? An answer to this question is given in a subsequent part of the paper. The fourth section relates to the discovery of induced currents of the third, fourth, and fifth orders;—that is, to the fact that the second current is found capable of inducing a third current, and this latter again another, and so on. The properties of these new currents are next examined, and the screening influence is found to take place between them; quantity is induced from intensity, and conversely; magnetism is developed in soft iron; decomposition is effected, and intense shocks are obtained, even from the current of the fourth order. A remarkable and important fact is stated in reference to the direction of these currents. If the direction of the battery current and that of the second be called plus, then the direction of the third current will be minus, of the fourth current plus, of the fifth minus, and so on. The application of the fact of these alternations is made. to the explanation of the phenomenon of screening before mentioned, and also to the improvement of the magneto-electrical machine. The last part of the paper relates to the discovery of secondary currents, and of currents of the several orders, in the discharge of ordinary electricity. Shocks are obtained from these; the screening influence of good conductors is shown to take place; magnetism is developed; and the alternations in the direction are found to exist as in the currents from galvanic induction. Some remarkable results are given in reference to the great distance at which the induction takes place. Experiments are detailed in which needles were made magnetic, when the conductors were removed to the distance of twelve feet from each other. Prof. Henry made a verbal communication, during the course of which he illustrated, experimentally, the phenomena developed in his paper. Stated Meeting, November 16. Present, twenty-four members. Mr. DU PONCEAU, President, in the Chair. The following donations were received:— FOR THE LIBRARY. The Good Fellow, by Paul de Kock. Translated from the French by a Philadelphian. Two Volumes. Philadelphia, 1837.-From Daniel J. Desmond, Esq. Allgemeiner Hand-Atlas der Ganzen Erde. Weimar, 1811.— From the same. Kongl. Vetenskaps-Academiens Handlingar, för Aor 1836. Stockholm, 1838.-From the Academy. Aorsberättelse om Framstegen i Fysik och Kemi afgifven den 31 Mars 1836; af Jac. Berzelius. Stockholm, 1836.-From the Royal Swedish Academy. Aorsberättelse om Technologiens Framsteg afgifven den 31 Mars 1836; af G. E. Pasch. Stockholm, 1836.-From the same. Aorsberättelse i Astronomien af S. A. Cronstrand. Den 31 Mart. 1836. Stockholm, 1836.-From the same. Aorsberättelser om Nyare Zoologiska Arbeten och Upptäckter, afgifne den 31 Mars 1835 och 1836, af B. Fr. Fries. Stockholm, 1837. -From the same. Aorsberättelse om Botaniska Arbeten och Upptäckter för Aor 1835. Afgifven den 31 Mars 1836. Af Joh. Em. Wikström. Stockholm, 1837.-From the same. Tal om Hydraulikens närvarande tillstand m. m. Af P. Lagerhjelm. Stockholm, 1837.-From the same. Aminnelse-Tal öfver Kongl. Vetenskaps-Academiens Framlidne Ledamot Friherre Lars A. Mannerheim, af A. G. Mörner. Stockholm, 1837.-From the same. Abhandlungen der Königlichen Akademie der Wissenschaften zu Berlin. Aus dem Jahre, 1836. Berlin, 1838.-From the Academy. Bericht über die zur Bekanntmachung geeigneten Verhandlungen der Königl. Preuss. Akademie der Wissenschaften zu Berlin. For July, Aug. Sept. Oct. Nov. & Dec. 1837; and Jan. Feb. March, April, May, & June, 1838. Berlin, 1837-38.-From the same. Essai sur le Madar, (Calotropis Madarii Indico-Orientalis) contenant l'Histoire naturelle de cette Plante, ses propriétés physiques, chimiques, et médicinales. Par J. N. Casanova, C. M. D. Traduit de l'Anglais par L. A. Richy. Calcutta, 1833.-From the Author. General Observations respecting Cholera Morbus. By J. N. Casanova, C. M. D. Philadelphia, 1834. From the Author. A Lecture on the Social and Moral Influences of the American Revolution. By Job R. Tyson. Philadelphia, 1838.-From the Author. The American Journal of the Medical Sciences. Edited by Isaac Transactions of the Agricultural and Horticultural Society of India. FOR THE CABINET. Three specimens of quicksilver ores, eight of silver ores, and fourteen of copper ores, from different localities in Chili; six specimens of various ores and minerals, also from Chili; eight fossils from the Cordillera; an ostrich egg from the Pampas of Buenos Ayres.— From Dr. J. N. Casanova. The Committee on the solar eclipse of the 18th of September, made a further Report in part, comprising the following observations: No. 30. Observation of A. Holcomb, at his Observatory, Southwick, Mass., with a seven feet Herschelian of his own construction, power 225, with red screen glass. Southwick is in latitude 42° 0′ 41" north; longitude 4h 51m 128, by Mr. Holcomb's triangulation with Springfield Court House, one of the points determined by Mr. Paine. Mr. S. C. Walker finds, from Mr. Holcomb's observation of the solar eclipse of 1836, for this longitude 4h 51m 13.28. Mean value 4h 51m 12.6s. h m 8 Beginning, 3 20 19 Mean time. End, 5 50 27 Do. Observation satisfactory. Doubtful one second. Sun's limb tremulous, and near horizon. No. 31. Observation of Prof. Albert Hopkins, at the Observatory of Williamstown College, Mass. Latitude, 42° 42′ 44′′, longitude 4h 52m 528. Astronomical clock regulated by a four feet transit instrument. Beginning, 3 17 19.9 Mean time. Good observation. (not observed) Sun too near the horizon. The Committee on Dr. Hare's paper on the Tornado which passed over a suburb of Providence, R. I., in August last, reported in favour of publication, and the Report was adopted. The phenomena and facts, stated in this paper, are quite consistent with those mentioned upon the authority of Prof. Bache, Mr. Espy, and other observers, relative to the Tornado which took place in New Jersey, at or near New Brunswick, in June, 1835, and of which an account will be found in the last volume of the Transactions of the Society. This paper embraced a letter from Zachariah Allen, Esq., a highly respectable gentleman of Providence, who was an eye-witness of the Tornado, having been quite as near to it as was consistent with safety. One of the facts noticed by Mr. Allen, Dr. Hare considers as tending to justify his opinion, that the exciting cause of these meteors is electrical attraction. Mr. Allen alleged that, as soon as the Tornado came into contact with the surface of the river, the water rose in a foam; that, under these circumstances, two flashes of lightning passed between the water and the overhanging clouds; |