"Meditationis est perscrutari occulta; contemplationis est admirari perspicua. . . . . Admiratio generat quæstionem, quæstio investigationem, investigatio inventionem."-Hugo de S. Victore. Cur spirent venti, cur terra dehiscat, Cur mare turgescat, pelago cur tantus amaror, J. B. Pinelli ad Mazonium. Archdeacon Pratt's Reply to Captain A. R. Clarke's Remarks on his Determination of the Figure of the Earth from Geo- detic Data ... Prof. Helmholtz on the Regelation of Ice The Rev. S. Haughton on Hanging, considered from a Me- Prof. R. Clausius on the Reflection of Light in the Atmosphere. 41 Prof. Challis on an Extension of the Principles of the Calculus of Proceedings of the Royal Institution :- Prof. Tyndall on the Vibrations of Strings Proceedings of the Royal Society :— Mr. C. W. Siemens on Uniform Rotation Observations on Skylight Polarization at Philadelphia, by Mr. On Motion in a Resisting Medium, by Dr. O. Schreck of Bremen. 80 ... Prof. R. Bunsen on Flame Reactions. (With a Plate.) Mr. J. Croll on the Influence of the Tidal Wave on the Motion Prof. Tyndall's Remarks on the Paper of Professor Magnus M. H. Caro on the formation of Rosolic Acid and Rosaniline.. 126 Archdeacon Pratt: to find what changes may be made in the arrangement of the mass of a body, without altering its out- Mr. D. Forbes's Researches on the Mineralogy of South America. 135 Proceedings of the Royal Society :- Proceedings of the Geological Society :- The Rev. F. W. Holland on the Geology of Mount Sinai. 152 Mr. H. Woodward on a new Genus of Phyllopodous Crusta- cea from the Moffat Shales, Dumfriesshire, on the oldest Mr. J. Plant on the Discovery of Primordial Fossils in the neighbourhood of Tyddynglwadis Silver Lead-mine.... 153 Prof. W. C. Williamson on a Cheirotherian Footprint from the base of the Keuper Sandstone of Daresbury, Cheshire 155 Contributions towards the more accurate knowledge of the Phe- nomena of Fluorescence, by Dr. Victor Pierre of Prague .. 159 Mr. F. Jenkin's Reply to Dr. Werner Siemens's Paper "On the Question of the Unit of Electrical Resistance Prof. R. Bunsen on the Phenomena observed in the Absorption- 177 Proceedings of the Royal Society : Page Sir B. C. Brodie on the Calculus of Chemical Operations. 227 Proceedings of the Geological Society : Mr. S. V. Wood on the Red Crag 230 .... 231 Mr. H. W. Bristow on supposed Remains of the Crag near 231 The Rev. O. Fisher on the Warp of Mr. Trimmer Lieut.-Colonel Neale on Gold-deposits in Ecuador 232 233 Mr. A. L. Adams on Bones of Fossil Chelonians from 233 Dr. J. Young on the Affinities of Chondrosteus, Ag., and 234 Observation on the Passage of the Spark of an Induction-coil through Flame, by A. Kundt 234 On the Deportment of Solutions of Glauber's Salt on Reduction 235 236 237 On the Use of Nitroglycerine in the Quarries of Vosgesian Sandstone near Saverne, by M. E. Kopp..... 238 NUMBER CCXVI.-OCTOBER. M. H. Wild on the Absorption of Radiant Heat by Dry and by 241 Mr. R. Gill on an Air-pump without Clearance. (With a Plate.) 256 The Rev. S. Haughton's Notes on Mineralogy 260 Prof. W. Beetz on the Development of Hydrogen from the Anode. 269 Prof. Challis on a Problem in the Calculus of Variations, in reply to Mr. Todhunter 278 Prof. W. A. Norton on Molecular Physics 283 Prof. C. Matteucci on the Origin of Muscular Power. 289 292 Notices respecting New Books :-Prof. A. C. Ramsay's Memoirs of the Geological Survey of Great Britain. Vol. III. The Geology of North Wales; with an Appendix on the Fossils, by J. W. Salter :-Sir W. R. Hamilton's Elements of Quaternions 306, 308 Proceedings of the Royal Society: -- Page Mr. W. Huggins and Dr. W. A. Miller on the Spectrum of a New Star in Corona Borealis 310 On the Figure of the Earth measured Geodetically, by Archdeacon Pratt, M.A., F.R.S. 313 On the Spectrum of Aqueous Vapour, by M. Janssen. 315 319 On the Diffusion of Gases through Caoutchouc, by MM. Aronstein and Sirks 320 NUMBER CCXVII.-NOVEMBER. Mr. R. Walker on Ancient Shell Mounds at St. Andrews. (With a Plate.).. 321 Dr. Ketteler on the Dispersion of Light in Gases 336 Mr. F. Galton on the Conversion of Wind-charts into Passagecharts...... 345 Dr. Everett on a new Proportion-Table equivalent to a Slidingrule 13 feet 4 inches long. 350 Prof. Jellett on a new Optical Saccharometer.. 357 Mr. J. Croll on the Influence of the Tidal Wave on the Motion of the Moon 361 Prof. Cayley on the Locus of the Foci of the Conics which pass through four given Points.. 362 M. H. Sainte-Claire Deville on Affinity and Heat 365 Mr. C. Brooke on the Dynamical Theory of Electricity 378 Prof. Cayley on Differential Equations 379 Dr. Atkinson's Chemical Notices from Foreign Journals...... 381 Proceedings of the Royal Society : Mr. J. C. Maxwell on the Dynamical Theory of Gases Theoretical and Experimental Researches on Thermoelectrical Currents, by M. F. P. Le Roux 390 394 On a means of Weakening the Solar Rays in the Focus of Telescopes, by M. Léon Foucault 396 On the Passage of Thermal and Luminous Rays through inclined Diathermanous and Transparent Plates, by H. Knoblauch.. 398 NUMBER CCXVIII.-DECEMBER. Mr. T. Graham on the Absorption and Dialytic Separation of 401 Mr. J. Gill on Change of State as affecting Communication of 420 Prof. Curtis on the Freezing of Water at Temperatures lower |