Observations and Reports (continued). Milan :-R. Osservatorio Astronomico di Brera. Osservazioni The Observatory. Das Switzerland :-Schweizerische Geodätische Commission. Bulletin Mensuel. Vol. The Survey. U.S. Department of Agriculture. Monthly Weather Review. December, 1893-January, 1894. 4to. Washington 1894. Journals. Agricultural Gazette of New The Department. South Wales. Vol. V. Parts 1-2. 8vo. Sydney 1894. Department of Agriculture, Sydney. Asclepiad. Vol. X. No. 40. 8vo. London 1893. Sir B. W. Richardson, F.R.S. Astronomical Journal. Vol. XIV. No. 1. 4to. Boston, Mass. 1894. Smithsonian Institution, Washington. Astronomische Nachrichten. Bd. CXXXIV. 4to. Kiel 1894. The Observatory, Kiel. Boletin de Minas Industria y Construcciones. Año IX. No. 12. 4to. Lima 1893. Cellule (La). Tome X. Escuela Especial de Ingenieros, Lima. Fasc. 1. 8vo. Louvain 1894. The Editors. General Medical Council. Dentists Register. 1894. 8vo. London. Fortschritte der Physik. Jahrg. XLIII. (1887). 8vo. Berlin Mr. W. J. C. Miller. General Medical Council. Morphologisches Jahrbuch. Bd. XXI. Heft 1. 8vo. Leipzig 1894. The Editor. Journals (continued). Nature Notes. Vol. V. No. 52. 8vo. London 1894. Selborne Society. Revue Médico-pharmaceutique. Année VII. No. 2. 4to. Constantinople 1894. Stazioni Sperimentali Agrarie Italiane. Vol. XXVI. The Editor. 8vo. Modena 1894. R. Stazione Agraria, Modena. Timehri: Journal of the Royal Agricultural and Commercial Society of British Guiana. Vol. VII. Part 2. 8vo. Demerára 1893. The Society. Zeitschrift für Biologie. Bd. XXX. Heft 4. Bd. XXXI, Heft 1. 8vo. München 1894. The Editors. Burdett (H. C.) Burdett's Official Intelligence. 1894. 4to. London. The Author. The Author. Greenhill (A. G.), F.R.S. A Treatise of Hydrostatics. 8vo. London 1894. The Author. Guppy (H. B.) River Temperature. Part 1.-Its Daily Changes and Method of Observation. 8vo. [Edinburgh 1894.] The Author. Hayter (H. H.) Victorian Year-Book. 1893. Vol. I. 8vo. Melbourne 1893. The Author. Johnston (R. M.) Handbook of Tasmania for the Year 1893. 8vo. Hobart 1894. Government Statistician, Hobart. Johnston-Lavis (H. J.) The Ejected Blocks of Monte Somma. Part 1. Stratified Limestones. 8vo. Edinburgh 1893. [And two other Excerpts.] The Author. Kelvin (Lord), P.R.S. Popular Lectures and Addresses. Vol. II. 8vo. London 1894. The Author. Marsh (O. C.) Restoration of Comptosaurus. 8vo. [New Haven] The Author. 1894. Praschkauer (M.) Ein Abriss ueber das Englische Arbitrations The Author. (Schiedsrichter) Wesen. 8vo. London 1894. Schwalbe (B.) Über wissenschaftliche Fachlitteratur und die Mittel dieselbe allgemein und leicht zugänglich zu machen. 8vo. Berlin [1894]. The Author. White (W. H.), F.R.S. A Manual of Naval Architecture. Third edition. 8vo. London 1894. Williamson (B.), F.R.S. Introduction to the of the Stress and Strain of Elastic Solids. The Author. Mathematical Theory 8vo. London 1894. The Author. Circular Case for a Rumford Medal, made out of the wood from an ash tree, until lately growing in front of Count Rumford's house, North Woburn, Massachusetts, and contemporary with him. Rumford Historical Association, North Woburn, Mass., through Dr. Ephraim Cutter. April 26, 1894. The LORD KELVIN, D.C.L., LL.D., President, in the Chair. A List of the Presents received was laid on the table, and thanks ordered for them. Pursuant to notice, Professor Henri Ernest Baillon, Professor Henri Poincaré, and Professor Eduard Suess were balloted for and elected Foreign Members of the Society. The following Papers were read: I. "On the Specific Heats of Gases at Constant Volume. Part II. Carbon Dioxide." By J. JOLY, M.A., Sc.D., F.R.S. Received March 9, 1894. (Abstract.) In the former experiments on this gas, recorded in the first part of this research,* the highest absolute density at which the specific heat was determined was 0.0378. In the present observations the deter "On the Specific Heats of Gases at Constant Volume," Part I,' Phil. Trans., A, vol. 182, 1891, pp. 73–117. minations of specific heat have been carried to densities at which the substance was partly in the liquid state at the lower limit of temperature of the experiments. Observations dealing with true specific heat, uncomplicated by the presence of thermal effects due to the presence of liquid, are limited by the density 0.1444. At this density the mean specific heat over the range, 12° C. to 100° C., is 0.2035. The following table contains a summary of the mean results of the experiments in which no liquid is present at the initial temperature. The range of these experiments lies between air temperature (12° to 16°) and steam temperature These observations, combined with those contained in Part I (loc. cit.), afford a well defined line, which rises slowly at the higher densities, turning away from the axis of density. According to an empirical equation to this line, the specific heat of carbon dioxide at constant volume is given in terms of its variation with density p, as follows: : Cy= 0·1650+0·2125p+0·3400p3. This is in fair agreement with the linear equation deduced in Part I from the limited number of experiments at low densities therein contained :: Cy 0.16577 +0.2064 p. In these experiments a spherical vessel of copper was used to hold the gas, having a voluminal capacity of about 86 c.c., a mass of 137 grams, and an estimated resistance to bursting of 300 atmos. This, as in the former experiments, was equilibrated against a similar vessel in a differential steam calorimeter. These vessels produced each a precipitation, due to its own calorific capacity of 21 grams of steam. It was found, however, that closely agreeing results (to 1 per cent. about) were obtained when the precipitation due to the gas fell to as little as 0·15 gram. II. "On the Specific Heats of Gases at Constant Volume. Part III. The Specific Heat of Carbon Dioxide as a Function of Temperature." By J. JOLY, M.A., Sc.D., F.R.S. Received March 9, 1894. (Abstract.) In order to investigate the question of the variation of the specific heat of carbon dioxide with temperature, a steam calorimeter was constructed having double walls of thin brass, between which the vapour of a liquid boiling under atmospheric pressure could be circulated. The vessels used in the experiments were hung in the closed inner chamber. Into this chamber steam could be admitted after the temperature had become stationary and the same as that of the jacketting vapour. In this way the initial temperature could be varied. Experiments at various densities and over four intervals of temperature were carried out. The densities chosen were 0.0456; 0-0800; 0-1240; 0.1800, and 0.1973. The intervals of temperature over which the gas at each density was investigated were: air temperature to 100°; 35° C. (boiling point of ether) to 100°; 56° (boiling point of acetone) to 100°, and 78° (boiling point of ethyl alcohol) to 100°. The results are plotted on 5 equi-density lines, and it was found most intelligible to plot the precipitation due to the calorific capacity of the gas between t, and 100° against the initial temperature t, in each case. If the initial temperatures are measured as abscissæ, starting from 0° C. at the origin, and the precipitations are set off as ordinates, the 5 equi-density lines so determined slope downwards to the right (the slope increasing with the density), passing, necessarily, through the point 100° C. on the axis of temperature in each case. If the specific heat is invariable these are right lines. This proves to be sensibly the case for the lines p=0·0456 and p 0.0800; those of lowest density. The next line, 0·124, is nearly rectilinear over the higher ranges, but pursued from right to left it rises markedly at the lower temperatures; thus indicating that the specific heat at constant volume falls in value with increasing temperature. The line p = 0.1800 and the one close above it, p=0·1973, show this variation very markedly. Their variation below the critical temperature is complicated by the presence of liquid. The following table contains the principal results. The column headed contains the weight in grams of the precipitation due to the |