摘要:

WE regret our inability, at the present moment, V~ 8 to climb to philosophical heights with Aristotle and to declare that man is a political animal, or to sink into the comfortless cynicism of Schopenhauer and to assert that human society is a collection of hedgehogs driven together for the sake of warmth. Somewhere between the two exaggerations lies truth-whatever that may be. In the meantime our function, as we conceive it, is to probe, analyse, compare, and classify phenomena in the purely agnostic spirit which is the life and hope of science. This may be regarded merely as a restatement of something already grown platitudinous, yet it may appropriately serve as a prologue to some observations upon. a programme of a forthcoming imperial event. On June 20 the inaugural meeting of the third Imperial Education Conference is to be held. It will be open neither to the public nor to the press, membership being confined to delegates appointed by the Governments of the countries composing the British Empire-usually the permanent heads of their education departments-together with representatives of certain Government departments in Great Britain. For the first time in the history of the Conference, also, a few seats have been allotted to representatives of local education authorities and the teaching profession.We are further informed that the advisory committee responsible for the arrangements, after consulting all the Governments of the Empire, " has drawn up a comprehensive agenda which covers not only important administrative questions but also a number of subjects of general educational interest." It is hoped, particularly, that some agreement may be reached on problems arising out of the variety of teachers' qualifications, salary scales, and superannuation, since these are matters where lack of reciprocal arrangements tends to hinder the movement of teachers from one part of the Empire to another. With that aspiration we are wholly in sympathy; it needs neither explanation nor argument. When we turn to the groups of more general educational subjects which are to be discussed, however, we feel some misgivings. There is to be a very necessary reference to education in relation to the pupil's after-career, and here special interest will be attached to the views of overseas Dominions on the recent report of the Consultative Committee of the Board of Education-a report on which we have already expressed our views (NATURE, Feb. 5). There is to be an important discussion on the difficulties of rural education, while other sessions will be devoted to the cinema and wireless in education, physical training, adult education and the problems involved therein; and, most importantly, there stands out a group of subjects " dealing with important new ideas and developments " which appears to pivot about " Empire History and Geography."Now it is after glancing at these suggested discussions that we would beg leave to submit our doubts as to whether sufficient advantage is to be taken of the tremendous possibilities afforded by the Conference. We do not, propose to inquire here into all the implications of the word ' Empire,' but we do desire to record our belief that, if it is to signify a progressive and cultural unity, it must sum up the felicitous relations of component parts based upon the mutual benefits arising out of trade and industry. To that end we believe a considerable part of the Conference should be devoted to an examination of the possibilities of pure and applied science. We make the suggestion because we observe that a special feature of the Conference is the leaving open of a whole session for the discussion of a subject to be chosen by the members during the second week. We have a special reason for urging that a broad discussion of the value-both cultural and practical-of science and technology in education is necessary in matters of Empire development. If we say that the functions of science include intercourse for the purpose of more efficient cooperation and economy of intellectual labour by the discovery of general laws governing typical situations, we shall not be placing anything on record for the first time. We shall, however, be repeating something to which controllers of education and directors of imperial destinies often give lip-service and very little more.It is the very fact that science possesses a more international quality than matters which usually come under the heading of literature or philosophy which makes us press specially its claims to the Conference. If it be neglected, if it be treated merely as incidental, a structure of recommendations will be erected by the Conference on an unsound foundation. We have already doubted whether man is a willing political animal; we certainly doubt his ability to hold an Empire together by a repetition of academic theories. The well-being and happiness of either a nation or an empire depend upon mutual production and exchange. Production and exchange-from raw material to the distribution of finished articles -involve change and adaptation of material, power, transport, and business organisation. All these, subdivided into the various branches of knowledge, form the subjects included in curricula of technical institutions. How far is the shaping of such curricula to be a subject of discussion by the Conference ? How far, in short, is science (in its broadest sense) to be dealt with with the view of producing methods which shall clear away disorders and anomalies capable of cure ?In what light, for example, will 'History' be treated ? Will there be an attempt to gain for the Empire the urge and the clarity of thought which might arise from a synthesis of those events which have made British imperial development possible ? How far have we clearly focussed the flow and direction of human endeavour arising out of geographical discoveries of the fifteenth century ?-Magellan's circumnavigation of the earth, the cosmic system of Copernicus and other liberations of the mind of the sixteenth century, the founding of experimental science by Galileo, Gilbert, and Harvey, and the vast spread of scientific knowledge which led up, finally, in the nineteenth century to the theory of evolutionthe application of which to branches of art and industry has powerfully aided the demolition of time and space, and has enabled us, with our steamboats and our railways and our telegraphs, to hold together in a developing understanding the far-spread units which make up the British Empire ? The focussing of these things would, we believe, give to the Conference an impetus towards clear and rational efforts to grasp and remove the stupid barriers which so often hold back development, and to use the great instrument of education so that it shall more swiftly build up the materials of progress. We realise that we may have laid ourselves open to the charge of waving our own particular flag of science and technology. It is not a charge we fear, since we have our own convictions concerning the liberal and cultural powers of what is often ignorantly regarded as 'merely utilitarian.' We realise, too, that we may be charged with beating the air, because all we have suggested will come within the purview of the Conference. If that be so, we shall plead guilty unblushingly. We shall freely apologise for traversing old ground even though, in making the apology, we insist that the fundamentals upon which education schemes should be built are so vital that their constant examination and repetition is not superfluous but supremely necessary.

ISSN:0028-0836    

DOI:10.1038/119841a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

THERE is an excellent arrangement in Austria I under which from time to time one of the most promising of their meteorologists, after a period of official work in the State service, is appointed to the professorship of meteorology at Innsbruck, where he has leisure for the closer study of that branch of the subject in which he has become specially interested. This results not only in additions to our knowledge on the frontiers of the subject, but also in text-books which give in collective form and in logical sequence a summary of our knowledge over some sector of the meteorological circle. Notable examples are the " Meteorological Optics " of Perntner and the " Dynamical Meteorology " of Exner. The present officer at Innsbruck, Prof. Defant, adds as his contribution a book on weather and weather forecasting which is a development of a small book prepared and published originally in 1916-17. The book is divided into three parts, corresponding with the author's general view of the subject. The first part, on weather, is devoted to a discussion of 'diagnosis '; the second part, on weather forecasting, indicates the methods to be followed in the 'prognosis.' The third part gives a summary of our knowledge of weather changes of longer period, a knowledge which has not yet reached the stage at which it can be applied for regular forecasts of months, seasons, or years in the European area.In an initial chapter Prof. Defant indicates the development from weather rules and the weather prophet to the synoptic chart as the scientific basis of forecasting. He reproduces an interesting chart, due to Brandes, showing the distribution of pressure and wind in Europe on March 6, 1783, the first synoptic chart in meteorological history. Detailed particulars are given of the revised International Code for Weather Telegraphy, but for some reason it is described as the 'Swedish' code, and Great Britain and Norway, where this code has been used since 1921 for international exchange, are represented as using different codes special to themselves. (There is an error on page 15, where the figure for alto-stratus is given as 4, which should have been allotted to alto-cumulus.) The importance of wireless telegraphy in post-War developments is emphasised, and a wireless installation is stated rightly to be now an essential complement to a weather service.There is a remark in this chapter the importance of which cannot be too often emphasised. In forecasting, and in any examination of meteorological observations by means of maps, accidental errors of observation can often be readily detected; but there are atmospheric conditions in which individual stations may show apparently irregular differences from other stations, and there is a risk that the most interesting and instructive meteorological situations may pass without investigation, owing to the observations being regarded as erroneous and ' corrected ' for the errors. In the second chapter an account is given of the connexion between wind and pressure. In the original analysis by Guldberg and Mohn, the motion of the air near the earth's surface was assumed to be steady motion with a balance between the three forces due to the pressure gradient, the effect of the earth's rotation, and the surface friction, the last named being taken to act directly opposite to the motion. Prof. Defant, following Sandstrom, shows that a better agreement with the facts is obtained if the frictional force is assumed to act in a direction which is inclined at a finite angle (38° for central Europe) to the direction of motion.This assumption of a single frictional force, which is essentially the vector difference between the force due to surface friction and the tangential stress due to transfer of momentum by eddies, obscures the physical reality. Actually the transfer of momentum to the surface layer from the layers above is so rapid that the tangential stress due to it is large in comparison with the forces due to the pressure gradient and the earth's rotation, even for a layer of finite thickness. The motion of the surface layer is, therefore, effectively determined by the balance between surface friction and tangential stress, acting in opposite directions along the line of motion. The pressure gradient and the earth's rotation do not directly affect in measurable degree the surface wind, or the wind in any layer where there is a rapid rate of change of horizontal velocity with height and the motion is turbulent; they determine completely the wind in those layers where the tangential stresses are small, i.e. generally in layers at heights of 1000 feet or more, and they play their part in the intermediate layers where the tangential stresses are of the same order of magnitude as themselves, layers from which the momentum to maintain the motion near the surface is transferred. The fact that the 'mass forces' due to pressure gradient and earth's rotation can be ignored in treating the surface layers, implicit in Taylor's discussion of the subject, was stated explicitly by Whipple in 1920. No mention is made of this in the book, and there is nowhere any account of the development in our knowledge of turbulence in the last fifteen years, and its applications in all dynamical and thermodynamical studies of the atmosphere. The statement on p. 30 that but for the earth's rotation the wind would blow direct in straight lines from the places of highest pressure to those of lowest pressure needs qualification; with curved isobars there would be usually a rotatory wind system irrespective of the earth's rotation, and waterspouts and dust devils would occur much as they do at present.Chap. iii. deals with the motion of the air and its connexion with cloud and precipitation, and it introduces the reader to the work of Bjerknes and the idea of fronts, lines of convergence and of divergence. It is pleasant to see in this chapter reproductions of trajectories of air over the Atlantic from Shaw and Lempfert's " Life History of Surface Air Currents." The reproductions are much superior in appearance to the originals printed by the British Stationery Office. In the description of a warm front on p. 47, Ci-Cu. should be Ci.St., and it ought to be noted that in the warm sector, where normally cloud diminishes and precipitation ceases and the barometer remains nearly steady, it is not infrequent to find an overcast sky with heavy precipitation and a rapidly falling barometer. Some account could appropriately have been given in this chapter or the next of " les systemes nuageux " and the work of Schereschewsky and Wehrle, which constitutes the contribution of French meteorologists to the recent development in forecasting. The discussion of the relation between the weather and typical forms of the isobars is an effort to combine the old ideas of cyclones and anticyclones and the new ideas of fronts dividing masses of air of different constitutions. Fortunately the new theories have, on the whole, gained pride of place. There is a good account of the ideas of Bjerknes and Solberg on the development of cyclones and occlusions, as well as an indication of the principal results of the important research of Bergeron and Swoboda, in which developments along a front extending from mid-Atlantic to eastern Europe in October 1923 were examined in detail and interpreted. The fifth chapter deals with the non-periodic variations of pressure and of the motion of cyclones and anticyclones in the European area. Van Bebber's wel4-known diagram is reproduced, and Hanzlik's penetrating analysis of the temperature conditions in anticyclones finds here an appropriate place. The difference between the cold rapidly moving anticyclone and the warm stationary, or slow moving, anticyclone is of fundamental importance.In the second part of the fifth chapter the author considers the constitution and origin of cyclones and anticyclones, and contrasts the wave theory of Bjerknes with the ' bar ' theory of Exner. According to Bjerknes, depressions arise from waves at the sloping surface of separation between the cold polar air and the warm tropical air, and come in families, whileaccording to Exner, depressions arise through a tongue of cold air projecting horizontally into a warm equatorial current and damming it up in such a way that vortical circulation results. Considerable space is naturally devoted to a consideration of thunderstorms and line squalls, on which the experimental work of Schmidt on the motion of a heavy liquid spreading under a lighter one has thrown so much light; the diagnosis is, however, quite inadequate without some account of the thermodynamics of the phenomena and of the part which the condensation or evaporation of water in the atmosphere plays in causing instability. The section on cyclones and anticyclones concludes with an account of periodic variations of weather. These are not sufficiently well established to be of much value in forecasting: the most interesting is a period between five and six days which Prof. Defant found in the general circulation of the northern hemisphere; this agrees generally with the theory of Bjerknes and Solberg on families of cyclones.The section on weather forecasting occupies only about one-fifth of the book, the author's view being that diagnosis is the most important part of the forecaster's education. After some general remarks and a short discussion of Richardson's investigation of the method of weather prediction by numerical process, the author considers the use which can be made of local observations and statistics in forecasting, and he gives an interesting account of a method of determining the delimitation of the districts into which a country must be divided for forecast purposes. He deals at some length with the rules of M. Guilbert and with the persistence of weather conditions. He examines in detail examples of weather charts for March 13, 1913, and June 1, 1924, and indicates how the charts are to be interpreted in the light of modern theory. Many people appear to consider that weather forecasting is the sole purpose of meteorology; according to Prof. Defant, it stands in the same relation to meteorology in general as an applied science stands to a pure science. There are meteorologists of the purer kind who consider that weather forecasting is a combination of drudgery and humbug by means of which funds are obtained for the prosecution of work fundamental to the extension of knowledge. Such a view is based on a misconception. The desire to forecast the future course of the weather is as legitimate an impulse to the scientific investigation which is necessary for its satisfaction as the desire to understand or investigate any natural phenomenon. The two impulses-the desire to understand and the desire to foretell-are in fact the motive force in scientific investigation, and neither can be classed as better or worse than the other.One of the principal difficulties of a forecast service is to obtain an objective test of the accuracy of forecasts. Prof. Defant indicates what progress has been made in this direction-unfortunately little. The subjective estimates of the accuracy or inaccuracy of weather forecasts formed by the public are of no real value, because a forecast covers a considerable number of phenomena and the public lays stress now on one and now on another; it is, moreover, influenced, broadly speaking, by its own optimism or pessimism. Such is Prof. Defant's view, but a good forecaster must have some understanding of the needs of the public and must himself emphasise in his forecast the elements which will affect most those forwhon the forecast is issued. Hitherto there has been no book on weather fore casting in which the post-War developments, boti in the collection of information and in its analysis have been presented in their appropriate place a part of the whole scheme of weather forecasting The present book is notable because it makes al endeavour to do this. Information which i scattered through many international reports ant through many dissertations is here available fo the reader. There are errors and gaps, but on th whole the result at which Prof. Defant aimed ha been achieved successfully.

ISSN:0028-0836    

DOI:10.1038/119843a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

MR. DAMPIER WHETHAM has chosen a most opportune time for bringing out his book upon the land. It is so clearly and interestingly written that it should appeal to a wide public, to those who know little about the land as well as to those who are directly interested in the land and in agriculture. There is no doubt that an ever-increasing number of people in Great Britain are being stirred to an interest in the land-but mainly from the political point of view. Now a purely political interest in the land can be dangerous unless it is balanced by some understanding of economics and of agriculture. The author is specially qualified to deal with the land problem precisely on account of his knowledge of economics and of. agriculture from the practical side. His moderate and carefully reasoned reply to the policies (overwhelmingly political) put forward by Mr. Lloyd George and the Labour Party is admirable. Mr. Whetham shows conclusively that to resort to such drastic change (which would certainly be in the nature of experiment) as nationalising the land is not warranted, and would be fraught with danger.It is interesting to note in this connexion that the decidedly socialistic government of Czechoslovakia, when it brought in sweeping land reforms, did not nationalise the land, but rather developed small ownership. The reason for this was given in the words of several of the leading statesmen of the country, that State ownership or nationalisation in any form could end in one thing only-the ruin of the agricultural industry. Perhaps of even more importance than his handling of "politics and the land " is Mr. Whetham's exposition of " economics and the land." He shows how and to what extent certain economic forces affect agricultural prosperity. In simple language he goes deeply into the economic questions which it seems obvious few of the land 5sreformers have studied or understood-and still fewer agriculturists. Yet they are questions which e every agriculturist as well as every reformer should s understand.In thus ably refuting the attacks upon the r existing land system in Great Britain, I feel that e Mr. Whetham gives the impression that he is more Is satisfied with the present system than he really is; it is quite true that he points out that the system is not perfect and could be improved, but I refer to the general impression. Mr. Whetham certainly regards the-landlord-tenant system more favourably than I do. Before the great depression of the 'eighties, I concede that it was about as good a system as could be devised, but during the past forty years it has steadily become more and more unsatisfactory, especially from the landowners' point of view. It is obviously satisfactory to the tenant. Discussing this question with a frank and outspoken farmer, he summed up thus: " As long as you landowners are content to put your hands in your pockets and pay for us, pray go on doing so; when you get tired of it, see that we can purchase under sound financial conditions." Mr. Whetham clearly does not favour the development of an increase in occupying ownership as a partial alternative to the tenancy system, and the strongest barrier against nationalisation; he fails to realise that unless occupying ownership is developed, then nationalisation of the land is inevitable. He points out that in the United States the tendency is away from ownership towards tenancy; but the farmers in the United States are, in the main, occupying owners, and the tenancy that is developing there is in no way like the British system, but rather a partnership tenancy resembling the metayer system in Italy and parts of France. Hand in hand with the development of occupying ownership in Great Britain might well go the creation of a system of partnership farming, but of a type very different from the me'tayer. Space does not permit me to give here a detailed account of the form of partnership farming which I advocate and have practised for nearly twenty years.Coming to another point, the author does his best to persuade us that the yield from the corn land of Great Britain is as high or higher than any other country in Europe (except Belgium). He bases his argument largely upon the statistics of a particularly urban economist who shows that the corn yields of Denmark when 'corrected' are no higher than ours. I am interested in this ' correcting' of yields, and in future I must not believe my eyes when motoring through the Fens or Lothians, but take consolation in thinking that the very heavy corn crops one sees on every side when 'corrected' are no heavier than those of the poorer soils in my immediate neighbourhood ! In general terms the corn lands of Great Britain are richer than those on the Continent, and the comparatively low average yield in France, for example, is due to the fact that the thrifty French peasant grows corn on land that we would not cultivate at all, and so the high yields of the Pas de Calais are pulled down. Mr. Whetham deals admirably with the law of diminishing returns, and points out that at present prices it would not pay greatly to increase the yield of corn in England, that the extra expenditure on artificials and cultivation would only increase the loss. But it is a very different matter if a considerable increase is secured not only without greater but actually with a decreased expenditure. Lucerne will grow over a wide area of land in England. My own experience is that on poor arable land sown with lucerne which is allowed to stand for six years and then ploughed up, the increase in soil fertility is sufficient to secure for five to nine years subsequent corn crops that will average up to double the corn crop normal to that land; and this with a great reduction to the manure bill. This indicates one direction in which costs of production can be reduced, and I am convinced that still more can be done to reduce costs by the high organisation of the farm as a unit than is generally realised.As regards the reverse of the medal-prices-I agree with Mr. Whetham that they are a governing factor, but if the prices are low, it is even more important that the farmer should get the potential maximum, that the spread between producer and consumer be reduced by organised marketing. A highly organised industry can always withstand depression better than one that is not organised. Finally, while I quite agree that England is much more naturally (and economically) a grass country than the Continent, there is no getting away from the facts that much land is under grass which is not suited for grass, that the area of first-class grass land is limited, and that we have millions of acres of poorly handled grass which it would be economic to improve. I do not make these criticisms in any carping spirit, but because I believe it is of supreme importance that agriculturists in Great Britain should realise that the Government is not going to assist them to any material extent, and that it rests with the members of the industry to explore for themselves every avenue that will lead to an improved position. I am convinced that Mr. Whetham's book will prove of utmost value in this direction. It will stimulate thought, and, above all, every one who reads it will have not only a comprehensive but also a balanced view of the agricultural situation in Great Britain as it is to-day.

ISSN:0028-0836    

DOI:10.1038/119845a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

"'Tis the sunset of life gives me mystical lore, And coming events cast their shadows before." (CAMPBELL.)THROUGHOUT the ages philosophers have X amused themselves with time, with little to go on but their own uncertain introspections. More recently the scientific worker has found himself compelled to examine this concept critically and has exposed its interlocking characteristics with space. From the theorist to the experimentalist is a short step in science, but here a difficulty arises from the intangible nature of the material to be handled. There is no doubt that the man-in-thestreet, the apparent ultimate arbiter of common sense, does not accord to time the same kind of reality as he accords to other objects in his universe. He has an uneasy feeling that it really is something purely psychological which dies with him, although he uses the same kind of terminology about it as he does about material objects. He talks of 'intervals of time,' of 'time flowing,' and so on; but if pressed he would probably agree with Bergson that only the present exists; past events have existed but do not now, although mental pictures or memories of them exist now; future events do not exist, no memories of them exist now, but pictures of them may be imagined now. The man-in-the-street may, however, be wrong. He has always been wrong, for has he not been rescued from the ignorance of the past ? Relativity gave him a shock, but while relativists may contend that A's present may be B's future, so that in a sense A may remember B's future, it is not contemplated that A may remember his own future. If Mr. Dunne is correct, on waking from a dream we may, like the lady in the limerick, " return on the previous night." There are two distinct portions to this book which ought to be dealt with separately, and the author practically does so. In the first part the startling experimental facts are described which serve as the end to which to direct an equally startling theory. The theory must wait, for it is so strange and unconvincing that the only justification for propounding and examining it would be found if the experimental facts turned out to be unimpeachable. Broadly, the theory assumes that our field of perception of events moves through time, and therefore its time-speed must be measured with reference to another and quite differently dimensioned ' time '; that this ' time ' must likewise involve the existence of a third 'time,' and so on, giving what the author calls ' serialism 'in time. Similarly our conscious perception of events, perceiving ourselves perceiving, involves the existence of a sequence of observers (ourselves) with the conscious observer at the head of the sequence, another form of serialism. On this as a basis, but apparently by an appeal to geometrical intuitions, the author seeks to show that every time-travelling field of presentation is contained within a field one dimension larger, travelling in another dimension of time, the larger field covering events which are past and future as well as present to the smaller field, and that all these are observable to the serial observer and therefore to the conscious observer at the head of the series. All that remains after that is for the author to show that the 'future ' will be best observed when the mind is freed from the normal waking images, and this is what he attempts to do experimentally.We may safely ignore the theory until the shock of the facts, if so they be, has spent itself. Whatever preconceived prejudices we may possess against what Mr. Dunne proposes to establish-and the present writer has them strongly-it must be at once admitted that the author appears to be a careful, sane experimenter quite alive to the dangers and pitfalls that may beset an observer in a strange field; and if only for the honest and straightforward manner in which he seeks traps and the precautions he takes to eliminate them, his work must be given due consideration. For years Mr. Dunne has kept a systematic record of his dreams recorded immediately on waking, since dreams fade away so rapidly. He piles up case after case of dreams that have been followed a few days later by their counterparts in actual occurrences. Mere coincidence in one or two details he rules out. For example, to dream of a pile of coins toppling over, and to see such a catastrophe next day, would not suffice. Any bank clerk might experience that without significance, but to dream of a pile of sixpences toppling off a red book and to experience the event shortly afterwards would require examination. To take an actual illustration at random: while staying at the Hotel Scholastika in Aachensee in 1904 he dreamed he was walking along a path between two fields separated by high railings, when suddenly a horse in a field on his left appeared to go mad, tearing about, kicking and plunging in frenzied fashion. Having glanced at the railings to see that he was safe, he was continuing on his way, when suddenly the horse, which had somehow entered the path, came after him. It was a full-fledged nightmare. Like a hare he sped towards a flight of stairs at the end of the path, the horse in close chase, when he awoke. Next day, while fishing with his brother, he witnessed a drama which tallied in most of its particulars with the dream. It was his brother who directed his attention to the plunging horse. Looking up, he saw the fields-smaller than in his dream-the path, the railings (also smaller), and the flight of stairs leading to a bridge over the river. In a moment the horse had jumped the railings and was tearing down the path towards them as if demented. It swerved, avoided the stairs and plunged into the river, swam towards the fishers, clambered out of the river, snorted, and calmly trotted off.These dreams the author claims were not impressions of distant or future events, but merely the usual commonplace dreams composed of distorted images of waking experiences, strung together in the usual half-senseless fashion peculiar to dreams. If they had happened on the nights after the events they would have exhibited nothing in the smallest degree unusual, but they occurred on nights before the events. The author claims to have convinced a number of sceptical friends who placed themselves under his guidance that such dreams occur to them also, so much so that one of them endeavoured to use it to spot a Derby winner . If this work is not a practical joke, and it does not sound like it, and if the author is sane, and there is ample contributory evidence of this, the subject he has opened up ought to be examined so that his contentions are either substantiated or demolished. The ordinary scientific worker will not easily concede that in effect unknown future events can influence the state of the brain in the present, except indirectly in the sense that the present state of the brain and the future events may be affected by a common agency. It is quite possible, on the other hand, that certain of the confirmatory events described that mainly involved action on the part of the author may actually have been suggested by the dreams. The present writer once dreamt that he had invented an incandescent gas mantle which he in his dream called the " E]ijah Mantle "! He has often since then thought of following up the suggestion. Although many of the illustrations vouched for in this book would be exceedingly difficult to explain away on these hypotheses, it would appear to be the hypotheses, if not the only ones, on which to proceed once the evidence has been thoroughly verified and sifted.

ISSN:0028-0836    

DOI:10.1038/119847a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

THE task of the populariser is becoming more T and more difficult. If he attempts to produce something better than the superficial stuff that is served up by the popular Press, he is met with two difficulties: first, that science itself is over-specialised, and the results achieved in each little compartment of study are of interest only to the very few who can appreciate them; and secondly, that the cultivated public on the whole lack the necessary mental background of scientific knowledge and the understanding of scientific method which would enable them to assimilate results of major or general value. But if his task is more difficult, it is also more important, and in both directions. For not only can he exercise great influence on the general thought of the community by skilful presentation of the matured and general results of scientific research, but he can also do great good to science itself by taking a bird's-eye view of the specialists' domains and extracting from their multifarious details something of general import, some view or theory which may not be altogether accurate, but may act as a stimulus, or even as an irritant, and lead to more adequate synthesis. There is a close connexion in fact between popularising and generalising. It is too often forgotten that science does not consist in the mere accumulation of knowledge, that facts buried away in papers and text-books do not by themselves constitute science. There is needed in addition the spirit of synthesis and the power to fuse all the facts into a coherent system which in its turn shall link up intelligibly with some general philosophical Anschauung. Prof. Huxley expresses this all-important point admirably in the following passage:"The works of man only live in so far as man vivifies them: and this corpus of fact that tosome people constitutes the reality of natural science is only a vast stamp-collection, no more than a lumber room, unless each generation in its turn will make it live. It lives most strongly (so is the human mind constructed) by being woven into the general background of some -general philosophy of things. The history of science shows us how a body of fact, comparatively inert and lifeless while held in one framework of opinion, may be seized by another more vigorous movement of the mind and used as a living battering-ram to beat open the doors of progress " (p. 164). Better, on the whole, a wrong or premature synthesis than no synthesis at all. It is a curious fact that some of the most potent theories, theories that have most stimulated thought and research, have been found in the long run, after a period of vogue, to be very largely wrong. One might instance Weismann's brilliant theory of the germplasm, which exercised an extraordinarily powerful and lasting influence on biological thought. The present volume of essays by Prof. Julian Huxley is a more heterogeneous collection than his previous book entitled " Essays of a Biologist," and some of the shorter articles and reviews might well have been omitted. There remain, however, many papers of real value, of interest both to the general public and, particularly in one case, to the professional biologist. Prof. Huxley's gifts as a popular exponent of biological science are undoubted; he is always lucid and interesting, and links up his themes with human life and literature in such a way as to appeal to any cultivated reader.The first half-dozen articles deal with the problems of heredity and sex in the light of modern genetics. It seems to us thatProf. Huxley states the gene theory in too confident terms. The paper on " Chromosomes, Mendelism and Mutation " is a triumph of lucid exposition, but it will give the ordinary reader the impression that the problems of heredity are all solved. But this is far from being the case. Other articles deal with " The Control of the Life-Cycle," " The Meaning of Death," " Birth Control," " Evolution and Purpose," and there is a sympathetic and penetrating study of the author's grandfather and his attitude towards religion. Apart from a number of republished reviews, the rest of the volume is taken up by two papers, hitherto unpublished, on " The Frog and Biology " and " The Tadpole: a Study in Developmental Physiology," the latter based upon an address delivered at the British Association meeting in Liverpool. The paper on the frog gives an interesting and well-illustrated account of the action of internal secretions upon metamorphosis and colour-change; the other, some 85 pages in length, is a very valuable sketch and well merits attention from the professional biologist-it is rather too ' strong meat ' for the ordinary reader. We have here a good summary and a thoughtful discussion of the modern work by Spemann, Harrison, and others, on this classical object. One is interested to see that the quite fundamental ideas of Wilhelm Roux on the importance of function are at last being given the attention they deserve.

ISSN:0028-0836    

DOI:10.1038/119848a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

THIs is a book which can be heartily recommended to all who are concerned with the chemical examination of the materials in question. It is, in fact, in many respects the best of all those dealing with the subject. The first 124 pages deal with the analysis of pigments, white, red, blue, yellow and brown, green and black; then follow two chapters dealing respectively with the analysis of mixed paints and with the examination of varnishes. Three appendices dealing with (a) specimen analyses, (b) a method for the determination of tung oil in paints and varnishes, and (c) distempers, together with index of subjects and index of names, complete the work. Each subject is treated in a comprehensive manner and the methods given or recommended are those which the authors, in the course of their large and varied experience, have found to be trustworthy. They are especially useful in the case of some of the rarer pigments, which are so frequently in analytical works either ignored or dismissed by a reference to " the usual methods of analysis " that, when applied, are so often found to fail. Full analytical details are always given, a course which should always be followed in analytical methods of this description. A large number of references appear at the end of each chapter, enabling any analyst who wishes to do so to consult the original papers. It is gratifying to note that the authors have made use of the specifications of the British Engineering Standards Association, to the committees of which they have given so much valuable advice. In view of the tendency to give viscosities in C.G.S. units, the a'uthors have rightly included instructions as to how this can be done (pp. 144-150), and it is to be hoped that with this lucid description now available, those concerned with the examination of varnishes will record the viscosities of the varnishes in C.G.S. units and not, as has been so frequently the case in the past, in arbitrary units which mean little or nothing to any one other than the observer. The only small criticism we have to offer is that the symbol pH might have been briefly explained (p. 163), as we know from experience that there are still a number of paint and varnish 'chemists' who are not conversant with its real meaning.In conclusion, we have no hesitation in saying that this book should be in the possession of every pigment, paint, or varnish works' laboratory.

ISSN:0028-0836    

DOI:10.1038/119849b0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

IN the larger problems of astronomy it is not to be expected, or indeed to be desired, that there should be universal agreement. The subject of this book, as indicated by the title, is the ultimate problem of all astronomical and physical research, and a final pronouncement at the present time is obviously out of the question. Cosmogony, in fact, has only just emerged from the field of unalloyed speculation, and the tentative hypotheses which can now be put forward are more of the nature of convenient summaries of known facts and indica tions of new directions of observation than aspirants to the dignity of absolute truth. In the volume before us, M. Verronet, following lines of thought previously laid out by Henri Poincar6, considers the problem of the past, present, and future constitution of the individual bodies in the universe and of the universe as a whole. He reaches some very definite conclusions, which differ considerably from the more familiar views which we associate chiefly with the names of Eddington, Jeans, and Russell. For example, he maintains that the interior of a star is homogeneous, and has a sensibly uniform temperature about double or triple the surface temperature. Needless to say, he rejects Eddington's theory of radiative equilibrium, which he regards as being mathematically impossible. The age of the sun is placed at a few million years, and the past history of the universe is held to be almost negligible in duration compared with the future. These views are sufficiently unfamiliar to attract attention, and since M. Verronet gives reasons for the conclusions at which he has arrived, his work demands respectful consideration. It will doubtless not meet with general acceptance, but may nevertheless have some part to play in the advancement of knowledge.

ISSN:0028-0836    

DOI:10.1038/119850a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

As the title implies, this is an attempt to treat electromagnetic theory as a branch of general mechanics. The fundamental unit is not the charged particle, the existence of which depends upon the existence of the corresponding opposite charge, but the electric doublet or dipole, the moment of which vanishes in a neutral particle. This makes it possible to deal with vector quantities, instead of the scalar quantities represented by ' charges.' Vector algebra is therefore liberally employed, and the author devotes 36 pages to a consideration of its principal operations. It becomes necessary to regard electrons as geometrical points, or rather as point singularities in the spacetime continuum. The author, as is natural in the atmosphere of Leningrad, seeks to break with the historical development of electricity, and as a first step discards the conception of the ether, which he regards as obsolete. It is an interesting attempt, but whether it will be fruitful is another matter.

ISSN:0028-0836    

DOI:10.1038/119851d0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

PINHOLES are a serious problem in the case of some photographs. For example, a number of pinholes in a delicate cloud photograph will quite spoil the effect, unless they are carefully spotted out. Spotting out may be easy for a professional, but the ordinary amateur finds a considerable difficulty in doing it properly, and if lantern slides are to be made the technique is still more difficult.The common cause of pinholes is that small particles get on the face of the plate and during exposure they cause shadows, which on the resulting negative appear as clear patches. Particles may get on to the plate at various stages of its history, but the plate makers never, or scarcely ever, admit that any particles can be on the plates before they are taken out of their wrappings. My own experience, however, is against this supposition. My procedure, up to quite recently, has always been the same; I have dusted out the dark slides, opened the packets of plates very carefully, and very carefully put the plates into the dark slides; but pinholes sometimes occur and sometimes do not, and the occurrence or non-occurrence of pinholes coincides with the use of a new box of plates. With all the plates from one box I may get many pinholes, with all the plates from another I get very few; the inference is that the particles that cause them are on the plates as they come from the makers. Moreover, I have opened plates in the light and have found minute particles on their faces. Quite recently I have heard indirectly from a leading firm of plate makers that it is almost impossible to prevent small fragments of glass from the cut edges of the plates from getting on to the sensitised surface; this agrees with my experience that the pinholes are worse round the edges of a plate than near the centre. The above observations were made on plates that had not been carried about in a dark slide. Of course, if this is done, pinholes must be expected even on plates which were the most immaculate when they left the maker. Since apparently plates can, and do, leave the makers with foreign particles on their faces, it would appear to be necessary to remove the particles before the plate is put into the dark slide. Thirty years ago or so the amateur used to be told to dust his plates; more recently; however, he has been told on no account to do this; it has also been stated, and often repeated, that dusting plates electrifies them and causes small particles to be attracted. No one who has so written can have tried the experiment; at ordinary room temperature and humidity I find that it is not possible to electrify a plate even by a very vigorous rubbing of the coated side. When, however, the plates are made very hot, and therefore dry, they can be electrified by fairly moderate rubbing; if, however, they are left for half an hour or so, they are found to have returned to their original condition. Backed plates are still more difficult to electrify by rubbing, though different makes differ in this respect; some backed Ilford Special Rapid Panchromatic and Wellington Spectrum plates showed no electrification when rubbed vigorously, even when heated to such a temperature that they could scarcely be touched by the hand; some backed Imperial Panchromatic plates, however, were easily electrified by rubbing, when made very hot. The Ilford and Wellington plates could be electrified by rubbing if the backing was removed and if they were heated. Thus in the ordinary way, at room temperatures, there is no danger of electrification even if the plates are rubbed quite vigorously. I now wipe the sensitised surface of the plate with a pad of velvet, and have found a very considerable diminution of pinholes as a consequence; a single sweep of the velvet across the plate is sufficient.Probably a professional finds little difficulty in spotting out pinholes, but, as I have said, the amateur finds a good deal of difficulty. When using watercolour, for example, if there is too much colour on the brush, or if it is too watery, the colour leaves the pinhole and collects in a circle round it, thereby aggravating the evil; if one uses the brush very nearly dry it entails taking fresh colour for nearly every pinhole, and the process becomes very laborious. I have lately, however, taken to using ink supplied by the Cambridge Instrument Co. for their recording apparatus; this ink consists of colouring matter dissolved in nearly equal proportions of glycerine and water with a small admixture of gum arabic. This used with a fine brush makes the best medium I know of for spotting out pinholes; it takes longer to dry than, say, water-colour, but this disadvantage is fat outweighed by its ease of application.

ISSN:0028-0836    

DOI:10.1038/119852a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

WE wish to announce a result which indicates an inner unity between the quantum theory and gravitational relativity. The connecting link is the wave theory of Schrödinger.Einstein's gravitational relativity is an invariantive treatment of particle dynamics, with respect to transformations of co-ordinates. Hence the notions of clocks, yardsticks, moving observers, etc., which be introduces to make his theory plausible, belong primarily to the classical kinematics of particles. On the other hand, Schrddinger makes his fundamental physical phenomenon a wave phenomenon: that is, a phenomenon expressed by a linear hyperbolic differential equation of the second order in four variables. It is thus not unnatural to seek for the real meaning of the Schrddinger theory in an invariantive investigation, not of a quadratic form, as in Einstein's theory, but of a differential equation: j, 4 i ~_1,..,4 a4 1 z' gA -x. + g± +o =0, +-1-= DetigAsi # 0. Cotton (Annales scient. de lecole normale superieure, 3o s6r. 17, 211-244; 1900; comp. also T. Levi-Civita, Atti R. Istituto Veneto, 8a ser. 15, parte 2, 1331-1357; 1913) has shown that this equation can be written in the form C: 2 pas + (D +F HX1, 2, X3, X4)+=U m#~-2pA±(-D+F-H(xl~xix x4) where gxi is a contravariant tensor, pv a contravariant vector, and I,..4 X ' g paps, H=D-F-igo. As Cotton points out, if we suppose that K 6H = Constant = 6C, K being the curvature scalar of the gx,\, the gan's and the p"'s are in general determined in one and only one way. If we identify the g2's with those of Einstein, and assume his equations KA, = 0, where KA, is the contracted curvature tensor, it follows that K = 0, and H = C. If we take for our constant of normalisation (:=47r hm2c', where m is the rest mass of the electron, c the velocity of light, and h the Planck constant, our wave equation assumes the form of the relativistic Schrodinger equation as given by De Donder in Bull. Classe des Sciences, Acad. Royale de Belgique, seances du 5 fevrier et du 5 mars, 1927. Thus the quantisation of the Schrodinger equation is determined by the Einstein equations.The vector R, apart from a constant factor, deterrn:.nes the electromagnetic vector potential. The Maxwell auxiliary equation, as De Donder points out, is D = 0. This can be satisfied without affecting our previous considerations if we change our dependent variable V, by multiplying it by an appropriate factor of calibration. To sum up, if we define our gravitational field in the proper invariantive manner in terms of a wave equation, the quantisation of this equation follows from the gravitational field equations. The equation also defines an electromagnetic potential, to which most of Weyl's considerations apply.A detailed discussion of the present theory will appear in a near number of the Journal of Mathematics and Physics of the Massachusetts Institute of Technology. We can make our fundamental equation homogeneous in order by the substitution u= Veixo. We then obtain a treatment of our theory analogous to that of O. Klein, Zeitschr.f. Physik, 37, 895-906; 1926. The fifth dimension turns out to be a mere mathematical convention that can be compared to the introduction of homogeneous co-ordinates in other parts of mathematics.May

ISSN:0028-0836    

DOI:10.1038/119853a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature