"It is obvious," he continues, "that the description given of the phenomenon is incomplete, for ductility, elasticity, variation of the resonance-plate, &c., co-operate to produce a more complicated phenomenon. I have tried a great many materials for undertones, and found that they fall, in this respect, into three groups. In the middle stand those materials which furnish undertones, that is, the great majority of all substances in general. On the one side are those substances which, as soon as the vibrations are pretty strong, give no resonance-tones, but merely an indeterminate noise; to this group belong rolled plate metal and most kinds of glass. On the other side are those substances THE DISRUPTIVE DISCHARGE TRICITY1 which, however strong the vibrations, always give the tone of OF ELEC system. Projecting from the plate of the air-pump was a short metal rod, which formed one conductor with the metallic parts of the air-pump, and, by means of a wire, with the uninsulated conductor of the Holtz machine. Electrodes of various forms were made to screw on to the ends of the rods. Of the two insulated brass balls one, A, was fixed; the other, B, could be moved along the connecting board. The wire joining a to the collar of the receiver is insulated with gutta-percha. The electrometer in connection with B is one of Sir W. Thomson's divided ring reflecting electrometers. BY means of the following method we have been able to investigate the laws of the disruptive discharge of electricity of high potential-a subject of investigation which is the complement of that in which Drs. Warren de la Rue and Müller have been simultaneously engaged. In making these experiments I have had the able co-operation in succession of Messrs. Salvesen, Connor, Stewart, Simpson, and Playfair. The method essentially consists in connecting the prime conductor of the Holtz machine, not with the electrometer directly, but with an insulated spherical ball placed at some distance from an equal spherical ball, the latter being connected with the electrometer. The woodcut represents, in situ, the apparatus which was used in the case of the gases. The receiver of the air-pump, which has a rod capable of moving air-tight, was attached to one of the conductors of the Holtz machine in such a manner that the conductor and the rod formed one conducting When the potential of A is raised by driving the machine, the potential of B is also raised, and this goes on until a discharge takes place between the electrodes inside the receiver. Hence the maximum deflection of the spot of light from zero is an indication of the difference of potential of the two surfaces between which the spark passed immediately before the discharge. By breaking the contact between the conductors of the Holtz machine before beginning to turn the wheel, and, by turning slowly and uniformly, we were able to make the image of the B wire move up continuously, and to be at rest at the instant of discharge. After the discharge took place the image fell back to zero, or a point near zero. We always noted the position taken up by the image when the conductor of the machine was completely discharged. The force resisting the deflection of the mirror is the action of two external magnets upon several small magnets fixed to the back of the mirror.2 One great merit of our method is the rapidity with which observations can be made. Three readings were in general taken for each entry. The mean of these is very probably free from any error due to accidental variations in the passage of the spark. An extensive series of observations have been printed Abstract by the author of thesis for D.Sc. and other papers printed in the recently issued part of the Transactions of the Royal Society of Edinburgh. By Alexander Macfarlane, M.A., D.Sc. 2 Our results were reduced to absolute measure by means of the absolute electrometer represented on the table. Sparks were taken between two platinum wires placed at right angles to one another. When one of the wires was heated by a voltaic current the electrometer deflection was diminished by about one-fourth of its amount. stant. We have also investigated the effect upon the electric spark of heating the air round the disks, the pressure being kept conThe deflections of the electrometer for a constant spark for temperatures from 20° C. to 280° C. indicate a curve which slopes down gradually as the temperature is increased, while the deflections during cooling give a curve which is somewhat lower at the lower temperatures. These experiments were made in Prof. Tait's laboratory, to whom we are indebted, not only for the use of apparatus, but also for ever ready advice. "Electric strength" is the term used by Prof. Clerk-Maxwell to denote the physical constant in question. I have added, for the sake of comparison, values deduced from the results of De la Rue and Müller and of Faraday, but the ratios given do not strictly give the relative electric strength, but the ratio of the lengths of spark when the difference of potential is kept constant. The difference of potential required to produce a spark between two spherical balls is approximately proportional to the square root of the length of the spark. This we have verified up to 15 cm. On proceeding to investigate the discharge through insulating liquids, we first took up oil of turpentine. The liquid was placed in a glass jar of 7 inches diameter and 5 inches height. A screw passing through the bottom of the jar served to fix the lower electrode, and also to afford conducting connection with the earth. We observed four modes of discharge: by means of threads of solid particles, by motion of the liquid, by a disruptive discharge, and by motion of gas bubbles. When a chain was formed the index of the electrometer behaved as if a current were passing. The discharge, when sufficiently great, broke the thread and turned into a spark. The liquid was more easily set in motion when its surface was not much higher than the upper plate. The bubbles of gas appeared to be formed by the passing of the spark. They were always attracted to the negative electrode. When the electrification was neutralised they of course adhered to the under surface of the upper disk; when the disk was electrified negatively they still adhered; when positively they were repelled so as as to remain suspended in the liquid or to adhere to the lower electrode, according to the greater or less distance between the electrodes. At a diminished pressure the bubbles produced at the upper surface were observed to effect the discharge by carrying the electricity with them to the negative electrode. The fact that it is possible to cause a shower of electrified bubbles to descend and produce a flash and sound on impinging on the lower surface appears to throw some light upon the nature of lightning balls. SCIENTIFIC SERIALS Annalen der Physik und Chemie, No. 10.-The loss of electricity by an insulated charged body in rarefied gas in an envelope that has conductive connection with the earth is here stated by Herr Narr to be due to two processes distinct in time and intensity, the first, one of outflow, rapid and intense, the other, one of dispersion, slow and weak. The intensity of the former increases with decreasing density of each of the gases used (CO, air and H), and also on substituting one gas for the other in the order just given, the density remaining constant. These differences between the gases decrease with the density, and in vacuum fal within the limits of errors of observation. In discussing these results, Herr Narr is led to reard the condensed layer of gas on the conducting system as an insulator, not as a conductor.-Dr. Holz finds that the specific magnetism of magnetic ironstone is the greatest of all magnetic substances hitherto examined. Its maximum permanent magnetism is nearly as great, and partly greater than that of steel as hard as glass. Its permanent magnetism is sooner removed in demagnetisation with the same external forces than that of steel, &c.-Dr. Strouhal enunciates the laws of a mode of sound-production not much studied hitherto, that, viz., of rapid swinging of a rod, a blade, or the like, in air, or the passage of air-currents over strong wires or sharp edges, &c. Herr Braun contributes a long and interesting paper on the development of electricity as equivalent of chemical processes.Herr Koch demonstrates the applicability of the method of determining coefficients of elasticity from the bending of short bars supported at the two ends, the sinking in the middle being measured by means of Newton's interference-bands, and he suggests a more thorough investigation of the elasticity of crystals, by the improved means he describes.-Some remarks on the atomic weight of antimony, with reference to Cooke's recent research, are communicated by Herr Schneider, American Journal of Science and Arts, November.-In the opening paper Prof. Dana considers the value of some distinctive characters generally accepted in defining certain kinds of rocks, as, "older and younger," foliated or not, and porphy ritic structure; showing them to be often trivial and inapplicable. -With regard to the relative agency of glaciers and sub-glacial streams in the erosion of valleys, Prof. Miles considers that the streams are of primary importance in working in advance of the ice in deepening and enlarging these valleys, and that the glaciers abrade, modify, and reduce the prominent portions lef by the streams, and give them the well-known glaciated sur 1 experimented on, but that its existence was quite unknown to the people of that country. The phenomenon had been known in China for centuries, and that, therefore, while he showed it experimentally to the Fellows, he did so in case there might be some there who had never seen it, in consequence of these magic mirrors being rare; but he desired it to be remembered that it was not the phenomenon itself but the explanation of it which he had the honour of bringing before them as new. After citing all the possible ways in which this curious reflect faces.-Prof. Holden describes certain cloud-shaped forms (obscuring the smaller forms of Janssen) observed on the sun's disc on September 16, and cites a like observation made by Prof. Langley, in 1873, who thinks the effect chiefly due to our own atmosphere, while disposed to admit the possibility of some obscuration in the sun itself.-A pseudomorph after anorthite, from Franklin, New Jersey, is described by Prof. Roepper; and Prof. Verrill gives an account of recent additions to marine fauna of the east coast of North America.-There is also a notice of Edison's sonorous voltameter.-Prof. Marsh's importing power could be accounted for, and referring to a number of ant contribution on the principal characters of American Jurassic dinosaurs has been previously referred to in these columns. Morphologisches Jahrbuch, vol. iv., Part 3.-Studies_on the innervation of the hair-bulbs of domestic animals, by R. Bormel, 70 pages, 3 plates.—On Gloidium quadrifidum, a new genus of Protista, by N. Sorokin.-The development of the knee-joint in man, with remarks on the joints in general, and the kneejoints of vertebrates, by A. Bernays.-The skeleton of the Alcyonaria, by G. von Koch, including a minute description of the skeleton in each genus, a general account of it, and a new. systematic arrangement, 33 pages, with 2 plates.-C. Hasse continues his studies on fossil vertebræ; this part is devoted to their histology, and is illustrated by 4 plates. Zeitschrift für wissenschaftliche Zoologie, vol. xxxi. Part 2.— Contribution on the Julidae, by E. Voges, dealing very considerably with the tracheal system and its development. There are descriptions of many new species of Julus, Spirostreptus, and Spirobolus; 68 pages, 3 plates.-On the development of the blastoderm and the germinal layers in insects, by N. Bobretzky, with figures chiefly of Porthesia chrysorrhaa.-On the genus Brisinga, by H. Ludwig.-On Aspidura, a mesozoic genus of ophiurid, by Hans Pohlig. On the structure and development of sponges, Part 5, by F. E. Schulze; another most valuable contribution, the author having now completely followed the development of Sycandra raphanus, 34 pages, with 2 beautiful plates. Parts 3 and 4 in one.-On the cerebral sulci in Ungulata, by Julius Krueg; the paper deals very largely with the foetal development of the convolutions, 50 pages, 4 plates.-Contributions to the anatomy of Ophiurans, by Hubert Ludwig, treating especially on the skeleton of arm and mouth, and the sexual organs, 50 pages, 4 plates.-On the generative organs of Asterina gibbosa, by Hubert Ludwig, I plate.-An account of the anatomy of Magelona, an interesting form, by Dr. W. C. McIntosh, of St. Andrews; translated from English for the journal, 72 pages, 10 plates.-On some cases of parasitism among Infusoria, by J. van Rees.-Brief notes on the development of Anodon, by C. Schierholz. SOCIETIES AND ACADEMIES LONDON Royal Society, December 12.-"The Magic Mirror of Japan," Part 1, by Professors W. E. Ayrton and John Perry, the Imperial College of Engineering, Japan. Communicated by William Spottiswoode, M.A., Treas. R.S., &c. The President stated that Prof. Ayrton had agreed to give, in the Friday evening discourse on January 24, at the Royal Institution, a full account of Japanese mirrors, so that on the present occasion he understood the authors of the paper merely proposed to enter very shortly into the subject. Prof. Ayrton commenced by remarking that mirrors in Japan held a very high position, and constituted the most prominent feature in the Japanese temples, taking the place of the cross in Roman Catholic countries, and that the principal mirror in the Imperial Palace ranked higher than even the Emperor himself. He referred to the important place the mirror held in the very limited furniture of a Japanese household; to the respect attached to it by the women, and to the fact that while the sword was considered as "the soul of the samurai" (or two-sworded class) the mirror was looked on as "the soul of the woman." He next showed experimentally the so-called magic property possessed by certain rare bronze mirrors, sold by the Chinese at about twenty times the cost of the ordinary mirrors of that country, and which consisted in these mirrors being able to reflect from their smooth polished faces the raised patterns of birds, flowers, dragons, or Chinese letters with which their backs were adorned. He stated that he had found this property to be possessed by a very small percentage of the Japanese mirrors which he had printed notices that had at various times appeared of the magic mirror, the majority of which were accompanied with a theoretical explanation, he remarked that as the authors had apparently not made direct experiments with the mirror itself to elucidate the cause of the phenomenon, but rather to have satisfied themselves with endeavouring to find out how it could be reproduced in Europe, it was not to be wondered at that many of the suggested possible explanations were very far from the truth. Up to the present time, he believed, the idea of inequality of density of the surface of the metal mirror produced naturally in cooling, or in the supposed process of stamping, seemed to have found most favour in the West, while the belief that this variation in density arose from trickery on the part of the maker was the view entertained in China. Sir David Brewster and Sir Charles Wheatstone, on the other hand, who also thought that trickery was the explanation, believed the artifice to consist in the maker skilfully scratching on the face of the mirror, before polishing, lines exactly corresponding with the pattern on the back. phenomenon his experiments, made during the winter of 1877-78, Prof. Ayrton next described what was the explanation of the had led him to, viz., that there existed extremely slight irregudirect vision), of such a nature that the thicker parts, corresponding, larities in the curvature of the polished surface (quite invisible to of course, with the raised patterns on the back, were flatter than the remaining convex surface, so that there was less dispersion of light from the thick portion than from the thinner. He experimental arrangements of convergent and divergent beams then described one of a series of diagrams illustrating various of light which the authors had availed themselves of, and the use of which constituted, he said, the essence of the system of investigation employed by Prof. Perry and himself, and he explained that if his theory of the phenomenon was correct, then placing the screen, on which the reflection of the light from the Japanese mirror was cast, in a certain position, the phenomenon ought to disappear, and again putting the screen in another position, the phenomenon ought to be inverted; that is, instead of a bright image on a dark ground, which hitherto had alone been what has been observed by previous investigators, a dark image of the pattern on a bright ground ought to appear. This disappearance and absolute inversion of the phenomenon he said he had found to actually take place, but that he was compelled from want of time to leave the experimental exhibition of it for the Royal Institution. Various other facts, such as the necessity of holding the screen rather near, but not very near, the mirror when ordinary sunlight without lenses was employed, was, like the inversion phenomenon just referred to, shown to be explainable only on the inequality of curvature theory, and not on the inequality of density theory. or The next question that arose was how was this inequality of curvature produced? This was explained to be due to the method employed by the Japanese for making the face of the mirrors convex, which method had hitherto been quite unknown to foreigners, but which Prof. Ayrton had, after much trouble, found to consist in scratching the face while cold with a megebo, distorting rod." During the operation the mirrors became visibly concave, but, receiving a "buckle," sprung back again so as to become convex when the pressure of the rod was reremoved. The thicker parts of these magic mirrors yielded less under the pressure, were made therefore less concave when under the rod, and sprung back less, or became less convex, when the pressure of the rod had been removed. He then showed how this explained the fact discovered by Prof. Atkinson, of the Imperial University, Japan, in 1877, that a small scratch made on the back of a mirror with a blunt nail, although producing apparently no effect on the other side, became nevertheless visible as a bright line on the screen when a light was reflected from the mirror. Prof. Ayrton concluded by remarking that while the Japanese knew nothing of the so-called magic phenomenon that formed the subject of the paper that evening, he had ascertained that they had used another property for their priestcraft, but the account of this he would reserve for the lecture at the Royal Institution. "On the Torsional Strain which remains in a Glass Fibre after Release from Twisting Stress," by J. Hopkinson, D.Sc., F.R.S. It has long been known that if a wire of metal or fibre of glass be for a time twisted, and be then released, it will not at once return to its initial position, but will exhibit a gradually decreasing torsion in the direction of The best method of approximating to an the impressed twist. expression of the facts has been given by Boltzmann ("Akad. ⚫ der Wissensch. zu Wien," 1874). He rests his theory upon the assumption that a stress acting for a short time will leave after it has ceased a strain which decreases in amount as time elapses, and that the principle of superposition is applicable to these strains, that is to say, that we may add the after-effects of stresses, whether simultaneous or successive. Boltzmann also finds that, if (t) T be the strain at time t resulting from a A twist lasting a very short time 7, at time = O, & (t) where A is constant for moderate values of t, but decreases when is very large or very small. A year ago I made a few experiments on a glass fibre, which showed a deviation from Boltzmann's law. The glass fibre examined was about 20 inches in length. The glass from which it was drawn was composed of silica, soda, and lime-in fact, was glass No. 1 of my paper on "Residual Change of the Leyden Jar" (Phil. Trans., 1877). In all cases the twist given was one complete revolution. The deflection at any time was determined by the position on a scale of the image of a wire before a lamp, formed by reflection from a light concave mirror, as in Sir W. Thomson's galvanometers and quadrant electrometer. The extremities of the fibre were held in clamps of cork; in the first attempts the upper clamp was not disturbed during the experiment, and the upper extremity of the fibre was assumed to be fixed; the mirror also was attached to the lower clamp. This arrangement was unsatis factory, as one could not be certain that a part of the observed after-effect was not due to the fibre twisting within the clamps and then sticking. The difficulty was easily avoided by employing two mirrors, each cemented at a single point to the glass fibre itself, one just below the upper clamp, the other just above the lower clamp. The upper mirror merely served, by means of a subsidiary lamp and scale, to bring back the part of the fibre to which it was attached to its initial position. The motion of the lower clamp was damped by attaching to it a vane dipping into a vessel of oil. The temperature of the room when the experiments were tried ranged from 13° C. to 13.8° C., and for the present purpose may be regarded as constant. The lower or reading scale had forty divisions to the inch, and was distant from the glass fibre and mirror 38 inches. Sufficient time elapsed between the experiments to allow all sign of change due to after-effect of torsion to disappear. In all cases the first line of the table gives the time in minutes from release from torsion, the second the deflection of the image from its initial position in scale divisions. Experiment VI.-Twisted for 121 minutes. 2 3 4 5 Scale divisions 191 170 148 136 126 119 I 7 1081 t ΙΟ 15 30 65 90 120 589 Scale divisions 97 841 631 41 34 28 31 The time was taken by ear from a clock beating seconds very distinctly. The first point to be ascertained from these results is whether or not the principle of superposition, assumed by Boltzmann, holds for torsions of the magnitude here used. If the fibre be twisted for time T through angle X, then the torsion at time t after release will be X {4 (T+1) − 4 (t)} where a = o'65, whilst for No. 7 (light flint) it is greater; but in the electrical experiment no sign of a definite deviation from the law of superposition was detected. Geological Society, November 20.-R. Etheridge, F.R.S., vice-president, in the chair.-Rev. James Crompton and John Dennis Paul were elected Fellows.-The following communications were read:-On the upper greensand coral fauna of Haldon, Devonshire, by Prof. P. Martin Duncan, F.R.S. The author in this paper stated that since the publication of his supplement to the British fossil corals, published by the Palæontographical Society, several new corals have been obtained at Haldon by Mr. Vicary, of Exeter. Twelve additional species were noticed, of which ten were new. This brings the total number of species in the Haldon Greensand up to twentyone. The new species are thus distributed :-Aporosa: Oculinidæ (1), Astræidæ (3), Fungida (5); Perforata: Turbinariæ (2); Tabulata (1). The paper concluded with remarks on the genera and species represented, from which it appeared that the coral fauna of Haldon is the northern expression of that of the French and Central European deposits, which are the equivalents of the British upper greensand. The Haldon deposit was débris of the age.-Notes on Pleurodon affinis, sp. ined., Agassiz, formed in shallow water, and the coral grew upon the rolled and description of three spines of cestracionts from the lower coal-measures, by J. W. Davis, F.G.S.-On the distribution of boulders by other agencies than that of icebergs, by C. E. Austin, C.É., F.G.S. December 4.-Henry Clifton Sorby, F.R.S., president, in the chair.-Rev. William H. Allen, George Grey Butler, John Dixon, Rev. William Downes, B.A., Joseph Drew, M.D., Arthur Tom Metcalfe, E. P. Monckton, M.A., Albert J. Mott, Philip Lutley Sclater, Ph.D., F.R.S., William Hobbs Shrubsole, and Alexander Thuey, were elected Fellows of the Society.-The following communications were read:-On some mica-traps from the Kendal and Sedbergh districts, by Prof. T. G. Bonney, F.R.S., and F. T. S. Houghton, B.A. The rocks described by the authors are mapped by the Geological Survey on quarter sheets 98 N.E., 98 S.E., and 97 N.W., and in parts briefly mentioned in the accompanying memoirs, under the generic name mica-trap. Seventeen examples are described macroscopically and microscopically, and of eight chemical analyses are given. It appears better to call one a porphyrite and two diorites (micaceous varieties). The remainder are all characterised by abundance of mica (biotite). Augite also appears to have been generally a constituent; but it has almost invariably been replaced by secondary products, calcite, dolomite, viridite, &c. Three are crystalline in structure; one of these is named minette, the others kersantite. The remaining eleven show a microcrystalline or cryptocrystalline base. It is proposed to call eight of them minette-felsite, the rest kersantite-porphyrite. These rocks commonly occur in rather narrow dykes; they are intrusive in Silurian strata, and, in the authors' opinion, are undoubtedly true igneous rocks.Pleistocene notes on the Cornish coast near Padstow, by W. A. E. Ussher, F.G.S. In this paper the author described certain deposits seen in a small bay near St. Enodock's chapel, and known as Daymer Bay, and in section at Greenway cliffs.The pleistocene history of Cornwall, by W. A. E. Ussher, F.G.Š. In the first part of this paper the author, from his own observations and the writings of other geologists, gave detailed descriptions of the various superficial deposits of Cornwall, as exposed in numerous coast-sections. In the second part he discussed the relative ages of these deposits, and proposed a classification. Physical Society, December 14.-Prof. W. G. Adams, president, in the chair.-Mr. W. Gleed and Mr. J. G. McGregor were elected members of the Society.-Prof. Guthrie read a note by Mr. C. Boys on a condenser of variable capacity. This condenser was designed for use in connection with the Holtz electrical machine to show the effect of condensation on the length of the spark. It consists of a test-tube coated externally with tinfoil to form the inner armature and a glass tube inclosing the test-tube, and having its outer surface covered with tinfoil for the outer armature. The inner tube can be slid out or in along the length of the external tube, and the capacity thereby varied. Prof. Guthrie showed that a spark from the Holtz machine could by its means be gradually reduced. Prof. Macdonnel stated that he had for some years used a similar apparatus, the inner coating, however, being strong sulphuric acid.-Dr. O. J. Lodge exhibited a differential thermometer in which saturated water vapour takes the place of air or other gas. This application is based on the fact that the pressure of a saturated vapour in contact with its liquid depends only on the temperature. An ordinary cryophorous answers the purpose when held so that the water occupies part of one bulb and a part of the stem next it; the greater the length of the water column in the latter, that is, the more horizontal the cryophorous is held, the greater the sensitiveness of the instrument. If, now, there be a difference of temperature between the two bulbs there will be a difference of pressure in the vapour in their interiors, and the level of the water will change until the pressure is equilibriated. When both bulbs are at one temperature the water in tube and bulb is on a level. Unlike air thermometers, the sensitiveness does not depend on the size of the bulbs or tube, and there is no increase of volume of the vapour. Another form consists of a U-tube, with bulbs at the end of each arm, each bulb having some liquid and the bend of the tube containing a short column of it, or, for greater sensitiveness, a series of films across the tube like diaphragms. This thermometer is found to be correct for temperatures below that of the ordinary temperature of the water and vapour, but inexact for high temperatures. With these latter the vapour tension is not the same throughout the tube, and distillation is set up. The instrument is a much more sensitive thermoscope than the air thermometer, and there is almost no limit to its sensitiveness to low temperatures. The radiation from the hand, held six inches from it, sensibly affects it, as also does the radiation from a piece of ice. For class purposes it is likely to be useful, from its simplicity and range of delicacy.-Mr. W. Clarke, Cooper's Hill College, from a series of experiments which he is making on the surface-tension of liquid gases, by means of their capillarity, gave the surface-tension of sulphurous anhydride as 2'3 milligrammes per square millimetre at -15° C. Royal Microscopical Society, November 13.-Mr. H. J. Slack, president, in the chair.-A paper was read by Dr. Royston Pigott on some further inquiry into the limits of microscopic vision and the delusive application of Fraunhofer's optical law of vision, in the course of which he described numerous experiments to show that this well-known formula depends upon the laws of diffraction from rays reflected by bright discs or objects, but that it failed when applied to dark lines which were capable of being rendered visible far beyond the limits therein laid down. The subject was illustrated by numerous diagrams and by objects and apparatus exhibited in the room.-The President detailed the result of some recent experiments to determine the distance at which a human hair could be seen under various conditions by ordinary unassisted vision. Mr. F. H. Wenham read a paper on the measurement of the angle of aperture of objectives, in which he described the method of measuring the true angle of aperture as distinguished from that of the angle of field with which it was commonly confused.-Mr. Henry Davis read a paper on the pygidium of insects, showing the organ commonly known by this name had its representatives in the Neuroptera, Gryllida, and other groups of insects, as well as in the flea and lacewing fly. He gave reasons for regarding it as a special organ of sensation conveying to the insect an intimation of the presence of dangerous enemies. Some discussion upon the subject took place between Mr. C. Stewart, Mr. Beck, Mr. Slack, and the author of the paper. Some further communications, arising out of correspondence with Mr. Bedwell, were laid before the meeting by the Secretaries.-Three new Fellows were elected. Institution of Civil Engineers, December 3.-Mr. Abernethy, vice-president, in the chair.-A paper was read on the heating and ventilating apparatus of the Glasgow University, by Mr. Wilson W. Phipson, M. Inst. C.E. VIENNA Imperial Academy of Sciences, October 17.-The following among other papers were read:-Remarks on Stephan's fundamental formula of electrodynamics, by Dr. Margules.-A hypothesis on the physical state of the sun, by Prof. Puschl.Light as a reagent, by Herr Bohatta.-On the Tonsilla and Bursa pharyngea, by Dr. Ganghofner. October 24.-On a simple apparatus for obtaining a constant gas pressure, by Dr. Handl.-A contribution to the doctrine of conic sections in descriptive geometry, by Prof. Miksic.-On meteorology of Alpine heights, by Dr. Hann. On the formation of a space-curve of the fourth order, with a double point on a conic section. November 7.-On the Venus transit of December 6, 1882, by Dr. Friesach.-Contribution to knowledge of internal friction in iron, by Herr Klemencic.-On the pitch of a tuning-fork in an incompressible liquid, by Prof. Kolacek.-Determination of orbit of the sixth comet of 1874. |