Front Matter

ADVERTISEMENT. The Committee appointed by the Royal Society to direct the publication of the Philosophical Transactions, take this opportunity to acquaint the Public, that it fully appears, as well from the council-books and journals of the Society, as from repeated declarations which have been made in several former Transactions, that the printing of them was always, from time to time, the single act of the respective Secretaries, till the Forty-seventh Volume: the Society, as a Body, never interesting themselves any further in their publication, than by occasionally recommending the revival of them to some of their Secretaries, when, from the particular circumstances of their affairs, the Transactions had happened for any length of time to be intermitted. And this seems principally to have been done with a view to satisfy the Public, that their usual meetings were then continued, for the improvement of knowledge, and benefit of mankind, the great ends of their first institution by the Royal Charters, and which they have ever since steadily pursued. But the Society being of late years greatly enlarged, and their communications more numerous, it was thought advisable that a Committee of their members should be appointed, to reconsider the papers read before them, and select out of them such as they should judge most proper for publication in the future Transactions; which was accordingly done upon the 26th of March 1752. And the grounds of their choice are, and will continue to be, the importance and singularity of the subjects, or the advantageous manner of treating them; without pretending to answer for the certainty of the facts, or propriety of the reasonings, contained in the several papers so published, which must still rest on the credit or judgment of their respective authors. It is likewise necessary on this occasion to remark, that it is an established rule of the Society, to which they will always adhere, never to give their opinion, as a Body, upon any subject, either of Nature or Art, that comes before them. And therefore the thanks, which are frequently proposed from the Chair, to be given to the authors of such papers as are read at their accustomed meetings, or to the persons through whose hands they received them, are to be considered in no other light than as a matter of civility, in return for the respect shown to the Society by those communications. The like also is to be said with regard to the several projects, inventions, and curiosities of various kinds, which are often exhibited to the Society; the authors whereof, or those who exhibit them, frequently take the liberty to report and even to certify in the public newspapers, that they have met with the highest applause and approbation. And therefore it is hoped that no regard will hereafter be paid to such reports and public notices; which in some instances have been too lightly credited, to the dishonour of the Society. I. Observations of the Second Comet of 1822, made at Rio de Janeiro. By Lieutenant (now Captain) William Robertson, R.N. Communicated in a Letter to Captain Basil Hall, F.R.S. . . . . . . . . . . page 1 II. On the performance of Fluid Refracting Telescopes, and on the applicability of this principle of construction to very large instruments. By Peter Barlow, Esq. F.R.S. Cor. Mem. Inst. of France, of the Imperial Academy of St. Petersburgh, &c. &c. . . . . . . . . . . . . . . . 9 III. Researches in Physical Astronomy. By John William Lubbock, Esq. V.P. and Treas. R.S. . . . . . . . . . . . . . . . . . . . . 17 IV. On the Transient Magnetic State of which various Substances are susceptible. By William Snow Harris, Esq. Communicated by Davies Gilbert, Esq. V.P.R.S. . . . . . . . . . . . . . . . . . . . . . 67 V. On the Nature of Negative and of Imaginary Quantities. By Davies Gilbert, Esq. V.P.R.S. . . . . . . . . . . . . . . . . . . . . . . 91 VI. On the probable Electric Origin of all the Phenomena of Terrestrial Magnetism; with an illustrative Experiment. By Peter Barlow, Esq. F.R.S. Cor. Mem. Inst. of France, of the Imperial Academy of St. Petersburgh, &c. &c. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99 VII. On the Equilibrium of Fluids, and the Figure of a Homogeneous Planet in a Fluid State. By James Ivory, A.M. F.R.S. Instit. Reg. Sc. Paris. Corresp. et Reg. Sc. Gottin. Corresp. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109 VIII. On a simple Electro-chemical Method of Ascertaining the Presence of different Metals, applied to detect minute quantities of Metallic Poisons. By Edmund Davy, F.R.S. M.R.I.A. &c. Professor to the Royal Dublin Society . . . . . . . . . . . . . . . . . . . . . . page 147 IX. On the Chemical Action of Atmospheric Electricity. By Alexander Barry, Esq. F.L.S. Communicated by John George Children, Esq. Sec. R.S., &c. &c. . . . . . . . . . . . . . . . . . 165 X. An Account of Operations carried on for ascertaining the Difference of Level between the River Thames at London Bridge and the Sea; and also for determining the Height above the Level of the Sea, &c. of intermediate Points passed over between Sheerness and London Bridge. By John Augustus Lloyd, Esq. F.R.S. F.R.G.S. & F.S.A. . . . . . . . . . . . . . . . . . 167 XI. On the Variable Intensity of Terrestrial Magnetism, and the Influence of the Aurora Borealis upon it. By Robert Were Fox. Communicated by Davies Gilbert, Esq. M.P. V.P.R.S. . . . . . . . . . . . . . . . . . 199 XII. Description of a Graphical Registrer of Tides and Winds. By Henry R. Palmer, Civil Engineer. Communicated by John William Lubbock, Esq. V.P. and Treas. R.S. . . . . . . . . . . . . . . . . . 209 XIII. On the Errors in the Course of Vessels, occasioned by Local Attraction; with some Remarks on the recent Loss of His Majesty’s ship Thetis. By Peter Barlow, Esq. F.R.S. Cor. Mem. of the Inst. France, Imp. Acad. Sciences St. Petersburgh, Acad. Sciences Brussels, &c. &c. . . . . . . . . . . . . . . . . . 215 XIV. On the Meteorological Observations made at the Apartments of the Royal Society, during the Years 1827, 1828, and 1829. By J. W. Lubbock, Esq. V. P. and Treas. R.S. . . . . . . . . . . . . . . . . . 223 Appendix. Meteorological Journal kept at the Apartments of the Royal Society, by order of the President and Council. The President and Council of the Royal Society adjudged the Royal Medals for the year 1830 as follows: A Royal Medal to David Brewster, LL.D., Fellow of the Royal Society, for his Communications to the Royal Society on the Polarization, and other Properties, of Light. A Royal Medal to M. Balard, of Montpellier, for his Discovery of Brome. CONTENTS. XV. Researches in Physical Astronomy. By J. W. Lubbock, Esq. V.P. and Treas. R.S. . . . . . . . . . . . . . . . . . . . . . page 231 XVI. Researches in Physical Astronomy. By J. W. Lubbock, Esq. V.P. and Treas. R.S. . . . . . . . . . . . . . . . . . . . . . 283 XVII. On a peculiar class of Acoustical Figures; and on certain Forms assumed by groups of particles upon vibrating elastic Surfaces. By M. Faraday, F.R.S. M.R.I., Corr. Mem. Royal Acad. Sciences of Paris, &c. &c. 299 XVIII. A Table for facilitating the Computations relative to Suspension Bridges. By Davies Gilbert, Esq. V.P.R.S. . . . . . . . . . . . . . . . . . . . . 341 XIX. An Account of the Construction and Verification of a Copy of the Imperial Standard Yard made for the Royal Society. By Captain Henry Kater, F.R.S. . . . . . . . . . . . . . . . . . . . . . . . . . . 345 XX. On the Theory of the Elliptic Transcendents. By James Ivory, A.M. F.R.S. Instit. Reg. Sc. Paris, et Soc. Reg. Sc. Gottin., Corresp. . . 349 XXI. On the Tides in the Port of London. By J. W. Lubbock, Esq. V.P. and Treas. R.S. . . . . . . . . . . . . . . . . . . . . . 379 XXII. On the extensive Atmosphere of Mars. By Sir James South, F.R.S. Communicated by His Royal Highness the President . . . . . . . . 417 XXIII. On the Friction and Resistance of Fluids. By George Rennie, Esq. V.P.R.S. . . . . . . . . . . . . . . . . . . . . . . . . . . . 423 XXIV. Further Experiments with a new Register-Pyrometer for Measuring the Expansion of Solids. By J. Frederick Daniell, Esq. F.R.S. Professor of Chemistry in King's College, London . . . . . . . . . page 443 XXV. Experiments on the Length of the Seconds Pendulum at the Royal Observatory of Greenwich. By Captain Edward Sabine, of the Royal Regiment of Artillery, F.R.S. . . . . . . . . . . . . . 459 XXVI. On the Sources and Nature of the Powers on which the Circulation of the Blood depends. By A. P. W. Philip, M.D. F.R.S. L. & E. . . . . . . . . . 489 XXVII. On the Influence of Screens in arresting the Progress of Magnetic Action. By William Snow Harris, Esq. F.R.S. . . . . . . . . . 497 XXVIII. On the power of masses of Iron to controul the Attractive Force of a Magnet. By William Snow Harris, Esq. F.R.S. . . . . . . . . 501 Appendix. Meteorological Journal, kept at the Apartments of the Royal Society, by order of the President and Council.