Ehrenberg), very few of the results of his labour in this DR. NEUMAYER ON GRAVITY AND TERRESTRIAL A gravity survey is, in connection with a thorough geographical survey of the Antarctic, one of the most urgent requirements of the science of our earth. There are no measurements of the gravity constant within the Antarctic region; indeed, they are very scarce in the southern hemisphere south of 30° lat. S., and they are so closely connected with the theory of the figure of our earth that it is hardly possible to arrive at any conclusive results in this all-important matter without observations within the Antarctic region. It is impossible to foretell what effect an exact gravity survey in that region might exert upon our views with regard to all physical elements which depend upon the radius of our earth. Apart from that consideration, we may hope for another important enlargement of the knowledge bearing upon the connection between ter restrial magnetism and gravity. Gravity observations have been so much simplified of late, by von Herack's ingenious apparatus, that it does not offer a serious difficulty to multiply gravity determinations within the Antarctic region, so that we may well be able to speak of a "gravity survey.' The allimportant question of the distribution of land within the South Polar region is closely connected with it. The International Geodetic Permanent Commission expressed it as their conviction that a gravity survey within that region would be of the greatest benefit for higher geodetic theories. The probable connection between gravity and terrestrial magnetism has already been referred to. But apart from this, a magnetic survey of the Antarctic region is of the greatest importance from other points of view. As, since the time of Ross, no other observations of the values of the magnetic elements have been made, we are perfectly ignorant of_the_values of the secular variations south of 50° lat., though this information is urgently needed for the construction of trustworthy magnetic charts required in navigation. Of the situation of the southern magnetic pole, and of its motion during the last fifty years, we are equally ignorant, though the facts are so highly important according to Gauss's theoretical deductions. Much as the mathematical theory of terrestrial magnetism has been developed, of the physical theory of that mysterious certainly to some considerable degree caused by the want of our force in nature we are yet in perfect ignorance. This defect is knowledge in higher latitudes. It seems as if the magnetic character of the South Polar region is such as would afford all netic conditions of the North Polar region. A glance at a facility for a sound investigation when compared with the magmagnetic map shows how entirely different is the distribution of the magnetic action in both polar regions. There is the interesting fact to be noticed in the south that the two foci of total intensity are situated on the side towards the south of the Australian continent, and nearly on the same meridian. The magnetic action which makes itself manifest by magnetic storms or disturbances reaches its highest degree likewise south of the Australian continent, whereas to the south of South America the storms become very scarce and of a similar magnitude to those in middle latitudes. This was most strikingly proved by the observations in Orange Bay and South Georgia during the period of international observations in 1882-83. Of course the magnetic south pole and the situation of the foci above mentioned, are in close connection with these facts, but the reason of their distribution remains unexplained. A discussion of all observations on southern polar lights also shows a conmagnetic disturbance. nection between their frequency and the maximum region of Though the examination of these few facts ought to prompt the institution of a vigorous examination of the south polar regions, the series is far from being exhausted: there is the question of the geoid-deformation, the phenomena of the tides, and the structure of the ice and its drifting. The resolution of the Sixth International Geographical Congress that the present century should not be allowed to expire without unveiling the mysteries of the south polar regions, ought to be carried into effect. All scientific institutions and societies trust that such will take place without any further delay. SIR CLEMENTS MARKHAM ON ANTARCTIC GEOGRAPHY. I need scarcely say how fully I concur in every word that has fallen from Dr. Murray on the subject of the scientific results, and more especially of the geographical results of an Antarctic Expedition. It is sufficient to point out the vast extent of the unknowD area, and that no area of like extent, on the surface of the earth, ever failed to yield results of practical, as well as of purely scientific interest by its exploration. But there is much more to be said in the present instance: because the little that we do know of the Antarctic regions points unerringly to the very great importance and interest of the results that are certain to attend further research. The ice barrier, discovered by Sir James Ross, is known to be the source of the immense ice islands of the southern polar sea. But it has only been seen for a distance of 300 miles. It requires far more complete examination before any approach to an adequate knowledge can be obtained, respecting the extent and nature of the supposed ice-cap in its rear. We know that the southern continent is a region of actual volcanic activity; but the extent, nature, and effect of that activity remain to be ascertained. On the Antarctic Circle land has been reported at numerous points, south of Australia and the Indian ocean, but it is unknown whether what has been seen indicates islets and rocks, or a continuous coast-line. Dr. Murray has pointed out that the whole southern continent is certainly not bounded by such an ice-wall as was seen by Sir James Ross, and is not covered by an ice-cap. But the extent alike of the ice-cap and of the uncovered land is unknown. We are ignorant of the distribution of land and sea, and of ice and water in summer, and of the causes which influence such distribution. These are some of the geographical problems to be solved. The investigation of each one of them will lead to further discoveries as yet undreamt of, which must needs be of the deepest interest to geographers. There are eminent men present who will no doubt refer to the results of Antarctic exploration as regards other branches of science. Combined together they make the discovery of the unknown parts of the Antarctic region the greatest and most important work that remains for this generation of explorers to achieve. METEOROLOGY AND ANTARCTIC EXPLORATION. Dr. Alexander Buchan stated that the remarks he was about to make would have exclusive reference to the first two paragraphs of Dr. Murray's address, under the heading of "The Atmosphere"; or, rather, more immediately to the relation between mean atmospheric pressure and prevailing winds. He supposed he had been asked to speak on this occasion, from the extensive and minute knowledge of the subject he had necessarily acquired in the preparation of the reports on atmospheric and oceanic circulation which were published as two of the reports of the scientific results of the voyage of H. M S. Challenger. The former of these reports, on atmospheric circulation, is accompanied by twenty-six maps, showing by isobars for each month and the year the mean pressure of the atmosphere, and by arrows the prevailing winds of the globe, on hypsobathymetric maps, or maps showing by shadings the height of the land and the depth of the sea; first on Gall's projection, and second on north circumpolar maps on equal surface projection. The isobars are drawn from mean pressures calculated for 1366 places, and the winds from even a larger number of places, distributed as well as possible over the whole globe. It is also of importance to note that averages of pressure and prevailing winds are published with the report-an accompaniment to the maps of mean atmospheric pressure and prevailing winds of the globe not yet given in any other series of maps of mean pressure and prevailing winds. This then is the work undertaken and published in these reports, which occupied seven years in preparing, as time could be spared from official duties. The result of the charting of the pressure and prevailing winds is this: stand with your back to the wind, then the centre of lowest pressure that causes the wind will be to the left in the northern hemisphere, and to the right hand in the southern hemisphere, a relation well known as Buys Ballot's law. In charting the 1366 pressures and the relative prevailing winds, no exception was found in any of the two hemispheres. This is one of the broadest generalisations science can point to. Some years ago a theory of atmospheric circulation was pub. lished by the late Prof. Ferrel which, as it is not accordant with the broad results arrived at in the report of atmospheric circulation in the Challenger Reports, calls for serious consideration on account of its bearing on any attempt proposed to be undertaken for the exploration of the Antarctic regions. One of the more recent expositors of this theory is Prof. Davis, of Harvard College, who, in his " Elementary Meteorology,' gives an admirable exposition of the results now arrived at by the various workers in meteorology, and of the opinions and theories promulgated by different meteorologists in different departments of the science. The book is largely used in secondary schools and colleges of the United States, and these views are all but universally held there, and are now spreading over other countries. The following extracts from Davis's book fairly represent these views as generally entertained. "The surface winds of the temperate latitudes, and the high level currents above them, sliding swiftly along on their steep poleward gradients, must all be considered together. They combine to form a vast aerial vortex or eddy around the pole. In the northern hemisphere this great eddy is much interrupted by continental high pressure in winter, or low pressure in summer, and by obstruction from mountain ranges, as well as by irregular disturbances of the general circulation in the form of storms" (p. 110). Now the facts of observation do not support the theory of the existence, at any season of the year, of a low barometric pressure, or an eddy of winds, round or in the neighbouring regions of the north pole. Observations do not show us any prevail. ing winds blowing homewards to the north pole at any time of the year. Further, no low barometric pressure occupies the immediate polar region in any month; but instead, the opposite holds good for the four months from April to July. In April and May the mean atmospheric pressure is higher in the region of the pole than it is anywhere in the northern hemisphere north of 43° lat. N.; and in June and July, also higher than it is anywhere north of 55° lat. N. Now the higher pressure in these four months necessitates the existence of upper currents in order to maintain this high pressure about the north pole. These upper currents toward the pole are exactly opposed to the requirements of the theory, which intimates that the upper currents in the region of the pole must necessarily blow not towards but from the pole. The actual centre in this hemisphere, north of the tropics, towards which the winds on or near the surface of the earth blow, is not the north pole; but, in the winter months, the low barometric depressions in the north of the Atlantic and Pacific respectively, and in the summer months, the low barometric depressions in the Eurasian and North American continents; and the sources out of which the prevailing winds blow, in the winter months, the high pressure regions in Siberia and North America; and in the summer months, the high pressure regions lying northward of these continents, which, as already explained, are virtually the polar region itself. These are the facts in all regions where the winds, according to the theory, become winds blowing over the earth's surface. As regards the southern hemisphere, Prof. Davis states that "In the southern hemisphere the circumpolar eddy is much more symmetrically developed." Again, "the high pressure that should result from the low polar temperatures is therefore reversed into low pressure by the excessive equatorward centrifugal force of the great circumpolar whirl; and the air thus held away from the polar regions is seen in the tropical belts of high pressure" (pp. 110, 111). The interpretation of this is that the remarkable low pressure region of the southern hemisphere is continued southward to the south pole itself, the pressure diminishing all the way; and that in the region of the south pole, the air currents poured thitherwards along the surface of the earth, ascend, and thence proceed northwards as upper currents of such enormous intensity and volume, that they pile up in the tropical region of the southern hemisphere a mean sea-level atmospheric pressure about an inch and a half more than the sea-level pressure near the south pole whence it starts. Now, to bring the matter to the business which this meeting of the Royal Society has taken in hand-if this theory be true and supported by the facts of observation, it is plain that no meteorologist could signify his approval of any scheme that could be proposed for exploring the Antarctic regions, it being obvious that these strong west-northwesterly winds, if they blow vortically round and in upon the pole, heavily laden, as they necessarily would be with the aqueous vapour they have licked up from the Southern Ocean, would overspread Antartica with a climate of all but continuous rain, sleet, and snow, which no explorer, however intrepid and enthusiastic, could possibly face. But is this the state of things? Let it be at once conceded that, as far south as about 55 lat. S., the prevailing winds and the steadily diminishing mean pressures on advancing southward fairly well support the theory. South of this, however, southerly and south-easterly winds begin to increase in frequency, until from 60 lat. S. into higher latitudes, they become the prevailing winds. This is abundantly shown from the winds charted on the maps of the Challenger Report, as well as from the unanimous experience of all those who have navigated this region from Ross to the present time. Thus the poleward blowing winds from west-north-west in these summer months stop short, at least, thirty degrees of latitude from the south pole. These prevailing S.S.E. winds necessarily imply, as has been shown in the case of the north pole, the existence of a more or less pronounced anticyclone overspreading Antarctica; which in its turn necessarily implies the existence of upper currents from the northward, blowing towards and in upon the polar region to make good the drain caused by the surface out-blowing southeasterly winds. It may therefore be concluded that both the surface winds and the upper aerial currents are diametrically opposed to the requirements of this theory. What is now urgently called for is a well-equipped Antarctic Expedition to make observations which will enable meteorologists to settle definitely the distribution of atmospheric pressure and the prevailing winds of this great region. Were this done, the position in the Southern Ocean of the great ring of lowest pressure that encircles the globe could be mapped out; and since it is towards this low-pressure ring that the winddriven surface currents of the ocean flow, a contribution would thereby be made to oceanography, of an importance that cannot be over-estimated, particularly as regards the great question of oceanic circulation. SIR ARCHIBALD GEIKIE ON ANTARCTIC GEOLOGY. Hardly anything is yet known of the geology of the Antarctic regions. By far the most important contributions to our knowledge of the subject were made by the expedition under Sir James Ross. But as he was unable to winter with his ships in the higher latitudes, and could only here and there with difficulty effect a landing on the coast, most of the geological information brought home by him was gathered at a greater or less distance from the land, with the aid of the telescope. Within the last few years several sealing vessels have brought home some additional scraps of intelligence, which only increase the desire for fuller knowledge. As regards the land, merely its edges have here and there been seen. Whether it is one great continent or a succession of islands and archipelagos may possibly never be ascertained. We know that in Victoria Land it terminates in a magnificent mountain-range with peaks from 10,000 to 15,000 feet high; but that elsewhere it is probably comparatively low, shedding its ice-cap in one vast sheet into the sea. The rocks that constitute the land are still practically unknown. The dredgings of the Challenger Expedition brought up pieces of granite, gneiss, and other continental rocks, and detritus of these materials was observed to increase on the sea-floor southwards in the direction of the Antarctic land. More recently several sealing vessels have brought home from the islets of Graham Land to the south of the South Shetlands pieces of different varieties of granite, together with some volcanic rocks and fossiliferous limestones. So far as these rocks have been studied, they do not appear to differ from similar rocks all over the globe. The granites have been found by Mr. Teall to be just such masses as might have come from any old mountain group in Europe or America. Among the specimens sent to me by Captain Robertson, of the Active, from Joinville and Dundee Islands, which form the north eastern termination of Graham Land, there was one piece of reddish jasper which at once attracted my attention from its resemblance to the "radiolarian cherts now found to be so widely distributed among the older Paleozoic rocks, both in the Old World and in the New. On closer examination, this first impression was confirmed; and a subsequent microscopic study of thin slices of the stone, by Dr. Hinde, proved the un. doubted presence of abundant radiolaria. The specimen was a loose pebble picked up on the beach of Joinville Island. have no means of telling where it came from, or what is its geological age. But its close resemblance to the radiolarian cherts so persistent in the Lower Silurian formations of the United Kingdom, raises the question whether there are not present in the Antarctic regions rocks of older Paleozoic age. We It would be of the utmost interest to discover such rocks in situ, and to ascertain how far their fossils agree with those found in deposits of similar antiquity in lower latitudes; or whether, as far back as early Paleozoic time, any difference in climate had begun to show itself between the polar and other regions of the earth's surface. Among the specimens brought home by Dr. Donald and Captain Larsen from Seymour Island, in the same region, are a few containing some half-dozen species of fossil shells which have been named and described by Messrs. Sharman and Newton, who suggest that they point to the existence of Lower Tertiary rocks, one of the organisms resembling a form found in the old Tertiary formations of Patagonia. Large well-developed shells of Cuculla and Cytherea undoubtedly indicate the former existence of a far milder climate in these Antarctic seas than now prevails. If a chance landing for a few hours on a bare islet could give us these interesting glimpses into the geological past of the south polar regions, what would not be gained by a more leisurely and well-planned expedition? But perhaps the geological domain that would be most sure to gain largely from such exploration would be that which embraces the wide and fascinating field of volcanic action. In the splendid harvest of results brought home by Sir James Ross, one of the most thrilling features was the discovery of a snowy volcanic cone rising amid the universal snows of Victoria Land to a height of more than 12,000 feet, and actively discharging "flame and smoke," while other lofty cones near it indicated that they too had once been in vigorous eruption. Ross landed on one or two islands near that coast, and brought away some pieces of volcanic rocks. If we glance at a terrestrial globe we can readily see that the volcanic ring or "circle of fire," which nearly surrounds the vast basin of the Pacific Ocean, is prolonged southwards into New Zealand. The few observations that have been made in the scattered islands further south show that the Auckland, Campbell, and Macquarrie groups consist of, or at least include, materials of volcanic origin. Still further south, along the same general line, Mr. Borchgrevink has recently (1894-95) made known the extension of Ross's volcanic platorm northwards to Cape Adare, the northern promontory of Victoria Land. He noticed there the apparent intercalation of lava and ice, while bare snowless peaks seemed still further to point to the continued activity of the volcanic fires. Some specimens brought by his expedition from Possession Island, were found by Mr. Teall to be highly vesicular hornblende-basalt, while one from Cape Adare was a nepheline-tephrite. This region is probably one of the most interesting volcanic tracts on the face of the globe. Yet we can hardly be said to know more of it than its mere existence. The deeply interesting problems which it suggests cannot be worked out by transitory voyagers. They must be attacked by observers stationed on the spot. Ross thought that a winter station might be established near the foot of Mount Erebus, and that the interior could easily be traversed from there to the magnetic pole. But it is not merely in Victoria Land that Antarctic volcanoes may be studied. Looking again at the globe, we observe that the American volcanic band is prolonged in a north and south line down the western side of the southern continent. That it has been continued into the chain of the South Shetlands and Graham Land is proved by the occurrence there of old sheets of basalt, rising in terraces over each other, sometimes to a height of more than 7000 feet above the sea. These denuded lavas may be as old as those of our Western Isles, Faroe, Iceland, and Greenland. But that volcanic activity is not extinct there has recently been found by Captain Larsen, who came upon a group of small volcanoes forming islets along the eastern coast-line of Graham Land. It is tantalising to know no more about them. Another geological field where much fresh and important information might be obtained by Antarctic exploration is that of ice and ice-action. Our northern hemisphere was once enveloped in snow and ice, and though for more than half a century geologists have been studying the traces of the operations of this ice-covering, they are still far from having cleared up all the difficulties of the study. The Antarctic ice cap is the larges in the world. Its behaviour could probably be watched along many parts of its margin, and this research would doubtless afford great help in the interpretation of the glaciation of the northern hemisphere. To sum up-Geologists would hail the organisation and despatch of an Antarctic Expedition in the confident assurance that it could not fail greatly to advance the interests of their science. Among the questions which it would help to elucidate, mention may be made of the following: The nature of the rocks forming the land of the Antarctic region, and how far these rocks contain evidence bearing on the history of terrestrial climates. The extent to which the known fossiliferous formations of our globe can be traced towards the poles; the gaps which may occur between these formations and the light which their study may be able to throw on the evolution of terrestrial topography. The history of volcanic action in the past, and the conditions under which it is continued now in the polar regions; whether in high latitudes vulcanism, either in its internal magmas or superficial eruptions, manifests peculiarities not observable nearer to the equator; what is the nature of the volcanic products now ejected at the surface; whether a definite sequence can be established from the eruptions of still active volcanoes back into those of earlier geological periods in Antarctic lands; and whether among the older sheets leaf-beds or other intercalations may be traceable, indicating the prolongation of a welldeveloped terrestrial flora towards the south pole. It is con The influence of the Antarctic climate upon the rocks exposed to its action; the effects of contact with ice and snow upon streams of lava; the result of the seaward creep of the ice-cap in regard to any lava-sheets intercalated in the ice. ceivable that portions of lava-streams might be broken off by the onward motion of the ice which they overspread, and might thus be carried out to sea, intercalated in or capping ice-bergsThe physics of Antarctic ice in regard to the history of the Ice Age in northern Europe and America. ANTARCTIC FAUNA. Although an ardent advocate of Antarctic exploration, Mr. Sclater acknowledged that, as regards the higher vertebrates, with which he was most conversant, there was little chance of the discovery of new forms of animal life in the South Polar continent. The Antarctic mammals and birds (of the latter of which about twenty species were known) were exclusively of marine forms. Not a single land-mammal or land-bird had been yet obtained in Antarctica. As regards the class of fishes and the marine invertebrates, the case was quite different, and great discoveries might be anticipated in these groups, where very little had yet been done. The most promising zoological subject of Antarctic exploration seemed to him, however, to be the further investigation of the extinct fauna. The few fossil remains already obtained indicated the former exist. ence in the South Polar area of a very different climate from that which now prevailed there, and further researches on this point might lead to most important results. The Prof. D'Arcy W. Thompson said that all we knew of the deep sea life of the Antarctic came from eight hauls of the dredge, which hauls were, by common consent of the naturalists of the Challenger, the most productive of the whole cruise. fauna of every ocean urgently demanded further exploration, for we knew now no more about the fauna of the deep-sea than was known a hundred years ago of the fauna of the shore. But the circumpolar fauna of the South, at the meeting of all the great oceans, presented problems of peculiar importance. He considered Dr. Murray's theory of a bipolar fauna," closely akin both in the Arctic and Antarctic, as not proven; but he believed that there were many remarkable cases of continuous distribution, especially along the cold waters of the Western American coast from the Antarctic into the North Pacific, and even to Japan. If the "bipolar hypothesis were broken down, Antarctic exploration would lead to new generalisations, not less interesting, to take its place. Admiral Sir William Wharton said that an Antarctic Expedition must be under naval discipline. He hoped that such an expedition would not be far off, and he felt sure there would be a rush of officers and men to join it. Sir John Evans, in briefly summing up the discussion, said it had maintained a high level, and that the meeting had been prolonged to an unprecedented hour in the Royal Society. All were agreed as to the immense advantages of an expedition, and he was sure it would find a warm advocate in the Hydrographer to the Admiralty. ON THE ABSORPTION OF LIGHT BY MR. JOHN BURKE has recently given to the Royal Society of London (see NATURE, vol. lvi. p. 261) the result of some experiments which afford an important indication of the mode of action of bodies during fluorescence, and which may lead to a clearer conception of Kirchhoff's law on the equality of the emissive and absorptive powers of bodies The following is one form of Mr. Burke's experiment :-A 1 Translation of a paper, by Prof. C. E. Guillaume, in the Revue Générale des Sciences, December 15, 1897. photographic plate, P (Fig. 1), is adjusted before two equal cubes of uranium glass, A and B, placed so that the light emanating from B is obliged to pass through A before reaching the photographic plate P. The source of light, s, rich in the ultra-violet, illuminates the cubes by rays parallel to the plate, which is screened from the direct action of the source. An image is first formed by letting the exciting rays act on the two cubes simultaneously. The plate is then displaced, and a second image is produced by illuminating each of the cubes separately, each for the same length of time as in the first experiment. The result is that on development the resultant impression of the two separate effects is always much more intense than that of the first due to the two conjointly. P S The simplest explanation of this curious phenomenon is to suppose that the cube A absorbs the light emitted by the cube B more strongly when it is in a state of fluorescence than when it is screened from the exciting source. At first sight this property of fluorescent bodies appears to be a direct consequence of Kirchhoff's law, all luminous bodies absorbing the radiations which they are capable of emitting. But on looking at the matter more closely we find that this law, which includes so many facts, does not directly apply to the phenomenon discovered by Mr. Burke. This law states, in general, that all bodies, at a given temperature, have an emissive power and an absorptive power which are equal for each kind of radiation they emit. But we see here a class of bodies which, without having their temperature visibly altered. have their absorptive power changed, in consequence of the fact that, by a cause ap. parently different from an ele vation of temperature, they emit, momentarily, and under the action of an external source, radiations which are extinguished at the same time as the excitation itself. By this excitation the molecule is not permanently altered, and it does not become susceptible of vibrating in unison with the light to which it had attained; but if, by an external cause, it is given this vibratory movement, then, and only then, it becomes a resonator for the radiations identically the same as that which it emits. Α B FIG. 1. A familiar illustration will give us a more vivid conception of the mechanism of the phenomenon. Let us suppose a sound wave to approach a fixed tuning-fork of another pitch; the wave will pass on unabsorbed. But if we force the tuning-fork in such a way as to make it emit a note identical with that of the wave which approaches it, then it will behave as a resonator and will evidently become absorbent to the passing wave. The tuning-fork is thus capable of absorbing the vibratory energy which reaches it, not merely when the latter corresponds to its natural period of vibration, but also when it possesses a period identical with that of the forced vibration that is momentarily imparted to it. It is probable, similarly, that the fluorescent molecules are excited momentarily to a forced vibration, and become, for an instant, susceptible of absorbing the vibrations of the same period. It will be found, perhaps, that the familiar statement of Kirchhoff's law will apply, on comparing the small number of fluorescent molecules in the uranium glass, to any molecules whatsoever which have been raised to a fictitious temperature This extension of the corresponding to their vibratory state. notion of temperature has already been suggested with regard to various luminous phenomena other than that of incandescence, but it had merely led, up to the present, to the heaping up of difficulties without arriving at anything conclusive. It seems to me far simpler to suppress the notion of temperature altogether in Kirchhoff's law, which is far too general to be limited by a conception that ought to have a precise and definite signification. THE STRUCTURE OF CRYSTALS.1 IT is impossible here to do more than call attention to these two memoirs: the subject with which they deal is too intricate to be intelligible without the aid of diagrams. The author of the first appears to hold quite peculiar views on the nature of valency and chemical combination Each atom is surrounded by a "sphere of action," and this represents the volume of the element; whereas the volume of a compound molecule is less than the sum of the volumes of its components, for their spheres of action are supposed to interpenetrate to a certain extent when combination takes place. Their partial interpenetration gives rise to a complex surface of action for the molecule, which may be of a polar character, and approximates in form to a sphere when the molecule consists of a large number of atoms. Crystallisation is due to the attractive juxtaposition of such polar molecules. For the author's general views the reader is referred to his previous work, "Die Kraft und Materie in Raume." The present memoir is an elaborate study of the development of a number of complex forms by the superposition of spheres layer by layer on one or other of a few simple "embryos"; for example, on a tetrahedron composed of four equal spheres in contact. The whole process is illustrated by twenty six excellent plates, which appear to be photographs of skilfully constructed stacks of balls. On all matters the author expresses himself with remarkable confidence, and claims to have solved the problem of crystallisation. We doubt, however, whether all the types of crystalline symmetry are covered by the author's hypotheses, and some of his groups appear to be incompatible with what is known of crystals. Mr. Barlow's first communication on the subject of crystalline structure was made to this journal (vol. xxix. p. 186) in 1883, and was also illustrated by the regular grouping of spheres of different sorts. That paper was characterised as an interesting and ingenious memoir" by the late Prof. Sohncke, who expressed the hope that his own criticisms (p. 383) would induce the author "to establish his theory in a more solid and more general way." Since that date Mr. Barlow has published several investigations on the subject, and the present memoir, which appears in the scientific Proceedings of the Royal Dublin Society, is an extended study of the close-packing of spheres of different sizes. In the arrangement and re-arrangement of such stacks he ingeniously traces a number of interesting analogies which lead him far beyond the features of mere crystalline growth and structure into chemical combination and decomposition, solution, diffusion, and the phenomena classed under stereo-chemistry. Mr. Barlow himself regards the close packing of spheres as representing the position of equilibrium of mutually repellent particles, and this he believes to be the key to all the problems considered; but the reader must be referred to the original memoir for the details. The study of crystalline structure as represented by the close packing of spheres or other figures is now being prosecuted by several investigators in very different ways, and with very different interpretations. The geometry of the subject is, of course, independent of all the speculations which gather round it, and deserves the very serious attention of chemists and physicists. UNIVERSITY AND EDUCATIONAL CAMBRIDGE.-Mr. Oldham, the University Lecturer in Geography, announces a public lecture on the North-west Frontier of India. Sir George Robertson, K.C.S.I., of Chitral | fame, will take the chair. The late Mr. Frank Chance has bequeathed 400 volumes to the University Library. The Museums Syndicate report that owing to the increase of the number of buildings under their charge, and the greater requirements for research and other students, the sum placed at their disposal for the annual maintenance of the scientific departments must be augmented by 300/. 1"Das Problem der Krystallisation." By A. Turner. Pp. 98; 26 plates. (Leipzig: 1897.) "A Mechanical Cause of Homogeneity of Structure and Symmetry geometrically investigated; with special application to Crystals and to Chemical Combination. By W. Barlow. Pp. 164. (Dublin: 1897.) A proposal is made by the Local Lectures Syndicate for the granting of a diploma in Arts to University Extension students who have passed through a prescribed course of study and examinations. DR. GOTTLIEB, assistant professor of pharmacology in the University of Heidelberg, has been provisionally appointed successor to the late Prof. Dr. W. von Schroeder. MR. A. E. BRISCOE has been appointed Principal of the new technical institute in course of erection at Stratford. Mr. Briscoe is at present head of the Physics and Electrical Department of the Battersea Polytechnic. REFERRING to the London University Commission Bill, 1898, which was introduced into the House of Lords by the Lord President of the Council on February 21, and read a first time, the British Medical Journal points out that it differs from the Bill of 1897 in the omission of the names of the Commissioners From the schedule appended to the Bill it appears that the constitution of the Senate is modified by giving to the Council of the City and Guilds of London Institute one member, and by_reducing the number of Crown nominees from five to four. The number of members of the Senate is thus retained at the same figure, fifty-five, or with the Chancellor, fifty-six. In the paragraph dealing with Faculties, the sub-section recognising examiners appointed by the University as members of the Faculties has been omitted. The instructions to the Commissioners as to examinations are practically the same, and the Senate will be required to hold separate examinations for internal and external students unless it otherwise determine, "either generally by regulation, or as to a particular subject by order ” But there is this rather important addition, that the Senate wil be required to communicate any such regulation to Convocation. Part II. of the Schedule is now headed, "Matters for which provision must be made." These include the adequate protection of all classes of students whether external or internal, collegiate or non-collegiate, the recognition of teachers of the University, and the regulations for the admission of internal students. The sub-clause dealing with this last point has been modified, and as it nows reads persons to be recognised as internal students will be "students who have matriculated at the University, and are pursuing a course of study approved by the University under one or more of the recognised teachers of the University." THE official report of the Proceedings of the recent annual general meeting of the Association of Technical Institutions, containing the address delivered by the President, the Right Hon. Sir Bernhard Samuelson, Bart., F.R.S., has been issued In the course of his remarks the President pointed out that much good will arise from the concordance between the various educational agencies which has been arrived at in ten or twelve county boroughs, one of the most conspicuous examples of which is Manchester, where the School Board, the City autho rities with their splendid technical schools, and the Owens College of the Victoria University are all acting in harmony, provided, on which a child can by intelligence and perseverance and constructing the ladder so much talked of, but still so rarely mount from the humblest to the highest intellectual position. As to the expenditure of the funds available for technical instruction. Sir Bernhard Samuelson presented the following ques tions to his audience :-Have we fully considered the relative value of the various degrees of technical education; would it have been better for the nation if the 800,000l. per annum of Customs and Excise Fund had been in the main devoted to the higher rather than to the primary and secondary grades of technical education? Would not the lower grades even have been better served if we had in the first instance made a determined effort to extend and improve general elementary and secondary education? Many educationists would answer these questions in the affirmative. SOCIETIES AND ACADEMIES. Royal Society, February 3.- "Researches in Vortex Motion. Part III. On Spiral or Gyrostatic Vortex Aggre gates." By W. M. Hicks, F.R.S. The chief part of the paper refers to a kind of gyrostatic aggregate. The investigation has brought to light an entirely new system of spiral vortices. |
