absolute rigidity with the actual values is hopeless. The fortnightly tidal component, due to the changing declination of the moon, is probably an exception, but the difficulty here is to extract this relatively minute component from the observations, and the material is consequently imperfect. The problem was attacked in a different way by G. and H. Darwin in 1881. The horizontal component of the lunar and solar disturbing forces must deflect the apparent vertical, and it was sought to measure this effect by a pendulum. The quantities to be determined are so excessively minute, and the other disturbing forces so difficult to eliminate, that the method was only carried out successfully by Hecker in 1907, and subsequently by Orloff in Russia. The results on the whole were to the effect that the observed deflections were about three fifths of what they ought to be if the earth were perfectly unyielding, and were so far in accordance with estimates previously made by Darwin and others, from the somewhat imperfect statistics of the fortnightly tide. There was, however, a discrepancy between the results deduced from the deflections in the meridian and at right angles to it, which gave rise to much perplexity. The question was finally set at rest by Michelson in 1916. He conceived the idea of measuring the tides produced in two canals (really two pipes half filled with water) of about 500 feet long, extending one N. and S., the other E. and W. These tides are, of course, of a microscopic character, their range is of the order of one hundredth of a millimeter, and they could only be detected by the refined optical methods which Michelson himself has devised. The observations, when plotted on a magnified scale, exhibit all the usual features of a tide-gauge record, the alternation of spring and neap tides, the diurnal and semidiurnal lunar tides, and so on. The theoretical tides in the canals can, of course, be calculated with great ease, and the comparison led to the result that the ratio which the observed tides bore to the theoretical was about .69, being practically the same in both cases. The whole enterprise was as remarkable for the courage of its inception as for the skill with which it was carried out, and was worthy of the genius which has accomplished so many marvels of celestial and terrestrial measurement. The perplexing discrepancy in the results obtained by Hecker at Potsdam is no doubt to be explained by the attraction of the tidal waters in the not very remote North Sea, and by the deformation due to the alternating load which they impose on the bottom. In Chicago, near the center of the American continent, these influences were absent. The question may be asked, What is the precise degree of rigidity which is indicated by these observations, or by others which have been referred to? Various answers have been given, based on observations of the tides, of the lunar deflection of the vertical, and of the period of the earth's Eulerian muta-: tion, on which I have not touched. The estimates have varied greatly, but they are all high, some of them extremely high. That they should differ among themselves is not surprising. The material is certainly not uniform, either in its elastic properties or the conditions to which it is subject, so that we can only speak of the rigidity of the earth as a whole in some conventional sense. Larmor and Love have shown that all the information that can be gathered, whether from the tides or from the Eulerian mutation, can be condensed into two numerical constants. This leaves a large degree of indeterminateness as to the actual distribution of elasticity within the earth. It is at all events certain that in regard to tidal forces the great bulk of the material must be highly rigid. In leaving this topic, it may be recalled that it was in this same connection that Kelvin was led to initiate the method of harmonic analysis as applied to the tides, as well as to accomplish much brilliant mathematical work, whose importance is by no means limited to the present subject. The whole theory of the tides and cognate cosmical questions afterwards became the special province of George Darwin, but after his death, work on the tides was almost at a standstill; until it was resumed by Professor Proudman and his associate, Dr. Doodson, in the recently established Tidal Institute at Liverpool. They have already arrived at results of great theoretic as well as practical interest, some of which I understand are to be brought before the association at this meeting. Within the last twenty years or so, light has come on the elastic properties of the earth from a new and unexpected quarter, viz., from a study of the propagation of earthquake shocks. It is pleasant to recall that this has been largely due to efforts especially fostered, so far as its means allowed, by this association. To John Milne, more than to any one else, is due the inception of a system of widely scattered seismological stations. The instruments which he devised have been improved upon by others, notably by Galitzin, but it is mainly to his initiative that we are indebted for such insight as has been gained into the elastic character of the materials of the earth, down, at least, to a depth of half the radius. It may be remarked that the theory of elastic waves, which is here involved, was initiated and developed in quite a different connection, in the persistent but vain attempts to construct a mechanical representation of the luminiferous ether which exercised the mathematical physicists of a generation or two ago. It has here at length found its natural application. One of the first problems of seismologists has been to construct, from observation, tables which should give the time an elastic wave of either of the two cardinal types-viz., of longitudinal and transverse vibration -takes to travel from any one point of the earth's surface to any other. It has been shown by Herglotz and Bateman that if these data were accurately known it should be possible, though naturally by a very indirect process, to deduce the velocities of propagation of the two types throughout the interior. Such tables have been propounded, and are in current use for the purpose of fixing the locality of a distant earthquake when this is not otherwise known. They are however admittedly imperfect, owing to the difficulty of allowing for the depth of the focus, which is not always near the surface, and is sometimes deep-seated. This uncertainty affects, of course, the observational material on which the tables are based. Some partial corrections have been made by Professor Turner, who almost alone in this country, amidst many distractions, keeps the study of seismology alive, but the construction of accurate tables remains the most urgent problem in the subject. Taking however the material, such as it is, the late Professor Knott, a few years ago, undertook the laborious task of carrying out the inverse process of deducing the internal velocities of the two types of waves referred to. Although it is possible that his conclusions may have to be revised in the light of improved data, and, it may be, improved methods of calculation, they appear to afford a fairly accurate estimate of the wave velocities from the surface down to a depth of more than half the earth's radius. Near the surface the two types have velocities of about 7.2 and 4 km per second, respectively. These velocities increase almost uniformly as we descend, until a depth of one third the radius is reached, after which, so far as they can be traced, they have constant values of 12.7 and 6.8 km per second, which, by the way, considerably exceed the corresponding velocities in iron under ordinary conditions. The innermost core of the earth, i.e., a region extending from the center to about one fourth of the radius, remains somewhat mysterious. It can certainly propagate condensational waves, but the secondary waves are hard to identify beyond a distance of 120° of arc from the source of disturbance. Knott himself inferred that the material of the central core is unable to withstand shearing stress, just as if it were fluid, but this must at present remain, I think, uncertain. It should be remarked that the wave-velocities by themselves do not furnish any information as to the elasticities or the density of the material, since they involve only the ratios of these quantities. The relation between the two velocities is, however, significant, and it is satisfactory to note that it has much the same value as in ordinary metals or glass. It is to be regretted that at present so little is being done in the way of interpretation of seismic records. Material support in the way of more and better equipped stations is certainly needed, but what is wanted above all is the coordination of such evidence as exists, the construction of more accurate tables, and the comparative study of graphical records.. These latter present many features which are at present hard to interpret, and a systematic comparison of records of the same earthquake obtained at different stations, especially if these are equipped with standardized instruments, should lead to results of great theoretical interest. The task will be a difficult one, but until it is accomplished we are in the position of a scholar who can guess a few words in an ancient text, possibly the most significant, but to whom the rest is obscure. Even on this rapid review of the subject it should be clear that there is an apparent inconsistency between the results of two lines of argument. On the one hand, the thermal evidence points to the existence of a high temperature at a depth which is no great fraction of the earth's radius, so high indeed as to suggest a plastic condition which would readily yield to shearing stress. On the other hand, the tidal arguments, as well as the free propagation of waves of transversal vibration at great depths, indicate with certainty something like perfect elasticity in the mathematical sense. The material with which we are concerned is under conditions far removed from any of which we have experience; the pressures, for instance, are enormous; and it is possibly in this direction that the solution of the difficulty is to be sought. We have some experience of substances which are plastic under long-continued stress, but which behave as rigid bodies as regards vibrations of short period, although this combination of properties is, I think, only met with at moderate temperatures. It is conceivable that we have here a true analogy, and that the material in question, under its special conditions, though plastic under steady application of forcé, as for instance centrifugal force, may be practically rigid as regards oscillatory forces, even when their period is so long as a day or a fortnight. But beyond that we can hardly, with confidence, go at present. I have chosen the preceding subject for this address, partly because it has not recently been reviewed at these meetings, and also for the opportunity it has given of urging one or two special points. It is evidently far from exhausted-the loose ends have indeed been manifest-but this should render it more interesting. It furnishes also an instance, not so familiar as some, of the way in which speculations which appear remote from common interests may ultimately have an important influence on the progress of science. It is true that the secular investigations into the form of the earth's surface have an importance in relation to geodesy, but certainly no one at the time of Laplace's work on this matter would have guessed that he was unwittingly laying the foundation of the whole mathematical theory of electricity. The history of science is indeed full of examples where one branch of science has profited by another in unexpected ways. I would take leave just to mention two, which happen to have specially interested me. It is, I think, not generally understood what an important part the theory of elasticity played in Rayleigh's classical determinations of the relative weights of the gases, where it supplied an important and indeed essential correction. Again, the mathematical theory of hydrodynamics, in spite of some notable successes, has often been classed as a piece of pure mathematics dealing with an ideal and impossible fluid, elegant indeed, but helpless to account for such an every-day matter as the turbulent flow of water through a pipe. Recently, however, at the hands of Prandtl, it has yielded the best available scheme of the forces on an aeroplane, and is even being appealed to to explain the still perplexing problem of the screw-propeller. To promote this interaction between different branches of science is one of the most important functions of our association, and differentiates it from the various sectional congresses which have from time to time been arranged. We may hope that this meeting, equally with former ones, may contribute to this desirable end. Let me close with a local reference. The last fifty years have seen the institution of local universities and university colleges in many parts of this country and of the Empire at large. Through these agencies the delights of literature, the discipline of science, have been brought within the reach of thousands whose horizons have been enlarged and their whole outlook on life transformed. They have become centers, too, from which valuable original work in scholarship, history and science has radiated. The University College of Southampton is now contemplating an increased activity and a fuller development. In this ambition it has, I am sure, the best wishes of us all. HORACE LAMB SCIENCE AND SOCIAL ETHICS1 PRIMITIVE man, with his rudimentary knowledge of good and evil, could not attain a level of existence much above that of the brutes, in spite of the superiority of his brain. Even to-day, men live almost as wild animals in the tropical forests of South America. The remains of Paleolithic man in Europe show us that he had a brain as large as ours, and his art proves his capacity for understanding; yet he lived in what we consider a barbaric state. Gradually, by slow and painful steps, he acquired knowledge and with its aid developed skill and undertook what we call, with boastful exaggeration, the conquest of nature. In reality, he learned to play a game with nature, increasingly complex and productive of results as he learned more and more of the rules. This game, as we now find it, is what we call civilization, and it needs little argument to prove that for its maintenance we require all the knowledge we can obtain, organized into what we call science. We can not even remain where we are; we are compelled by the logic of events to go forward or backward, and progress depends on knowledge. Good intentions are of little avail without it, and the ignorant are like poor players who, doing the best they can, ruin the music of an orchestra. Thus it is impossible to be good without being wise, if we understand the word good in a pragmatic sense, as meaning good for something. Yet we must agree that science alone can not adequately minister to human needs. If a human being is nothing more than a temporary arrangement of atoms of carbon, hydrogen, oxygen, nitrogen and some other elements, our whole conception of human values seems to have little basis in reality. Or rather, is what reality it possesses unstable, evanescent, insignificant in relation to the universe? Is human life a tragedy because a comedy, a thing so ridiculous with its serious poses and heroic gestures that the gods, if there be such, must be convulsed with laughter? Well, we do not believe that for a moment; we could not believe it and be sane. Huxley was perhaps the most typical exponent of modern science, yet his great friend Michael Foster had this to say of him: Great as he felt science to be, he was well aware that science could never lay its hand, could never touch even with the tip of its finger, that dream with which our little life is rounded; and that unknown dream was a power as dominant over him as was the might of known science; he carried about with him every day that which he did not know as his guide of life no less to be minded than that which he did know. 1 Read at the symposium held by the Southwestern Division of the American Association for the Advancement of Science, Boulder, June 8, 1925. Recently, having occasion to write an article in commemoration of the hundredth anniversary of Huxley's birth, I tried to imagine what his counsel would be, were he among us. I fancied that it might be somewhat as follows: You can not have successful democracy without moral sense, and that must show itself equally in tenderness of heart and honesty of purpose. It is not enough to mean well; you must do well, cooperating with the universe in which you live. The honest man faces the facts of existence and governs his conduct accordingly; he throws aside all sham and pretense, as soon as it is ascertained to be such. These are not mere pleasing generalities, but stern precepts in a land where ignorance is often enthroned, and masses of people pretend to believe that which in their hearts they know to be false. Power without wisdom, action without knowledge, must lead to catastrophe, no matter how excellent the political system, how worthy the traditions of the past.2 There was a splendid integrity about some of the prophets of old, who offered eternal wisdom in the setting of the knowledge of their day. Yet the parable of the new wine in old bottles shows that our modern dilemma is of very respectable antiquity. It is not difficult to perceive what Jesus Christ would have to say about it, were he once more a man among men. Just as we have made over our lives to suit modern invention and discovery, so must we make over our philosophy to suit modern knowledge. But in essence both the lives and the philosophy remain the same, or at least retain eternal elements. Are we to perish like some butterfly which, having attained the winged state, should insist upon trying to eat cabbage leaves, instead of sucking the nectar of flowers? The matter is of enormous importance, and we must concede this virtue to the enemies of science, that they perceive it to be such. Unquestionably, the progress of the modern world, in its varied aspects, severely taxes the stability and even the sanity of the modern mind. Since we can not go back to barbarism, and all agree on that, it only remains to make readjustments which shall create harmony rather than discord, wholesomeness rather than a chaos of disconnected and irreconcilable fragments. What does this actually involve? It seems to me that it involves on the one hand the possession of what William James called over beliefs, transcendental conceptions of value and virtue which find their main justification outside the field of science; and, on the other, a frank and full acceptance of the testimony of the human senses, not as rigid orthodoxy, but as something dynamic, ever converting reality into truth. The modern man, possessed with these ideas, is bound to reject the mass of ancient 2 Nature, May 9, 1925, p. 750. miracles, some as apparently pure inventions, others as misinterpretations of facts actually observed. He may still often use metaphor, because our language is full of it, and perhaps the more freely because he knows what he is trying to express. He will not lose the sense of mystery or the feeling of awe, as he contemplates the world about him. Rather, these feelings will be deepened and broadened, as he perceives that truth is ten thousand times more wonderful than any fiction. What can he say to those who fear that the loss of faith in the images of the past will imperil the essential verities? He can not, he must not, treat the matter lightly, as a thing of no account. The danger is real, and the problem has to be met. But Christ long ago pointed out the futility of trying to meet it in a half-hearted way. The new wine would burst the old bottles, and everything would be lost. This we can not endure, any of us, and those who would insist on confining the growing, living science and religion of the day within the boundaries of ancient tradition are themselves the wasters of that which they hold most precious. UNIVERSITY OF COLORADO T. D. A. CoCKERELL SCIENTIFIC EVENTS RUSSIAN SCIENTIFIC EXPEDITIONS ACCORDING to the New York Bureau of the Russian Telegraph Agency an expedition is being sent into the provinces of Saratov and Ulyanovsk (formerly Simbirsk) to study the vicissitudes of culture during the prehistoric period on the Volga river, the main waterway of the East European plain. An expedition is leaving for Daghestan and the surrounding territories to study the languages, monuments, architecture, art and antiquities of Daghestan. A four-months' excursion is being organized to Krasnokokshaisk, Penza, Kazan and Sarapul to study the language and culture of the Finnish races in those districts, particularly of the Mari, Votiaks and Mordvans. A series of scientific expeditions is being organized to Central Asia. The first expedition will leave for the lake of Issik-Kul to investigate the possibilities of establishing large fisheries which may prove of great economic importance. Another expedition will be sent to the mountainous region of Turkmenistan to gather materials on the flora and fauna of that region. An expedition is being organized to Kazakistan (Kirghiz Republic) to gather valuable fossils of animals and plants contained in the slate deposits of the marine period. Other expeditions were sent to the Pamire and Tadjighistan. The largest expedition has been sent to Northern Ferghana to study the rich natural resources of the region. Another expedition is leaving for Yakutia for a period of five years. The expedition will study the life and customs of the Yakuts, the physical types of the population, the spread and causes of such diseases as trachoma, leprosy and psychiatrical phenomena observed in Yakutia, the cause of the degeneration of the Yakut women, and so on. THE A. C. S. NEWS SERVICE In response to a request from the editor of SCIENCE I am glad to give the following details regarding the News Service of the American Chemical Society. The service was founded in 1917 with Dr. Allen Rogers, of Pratt Institute, contributing part time to its management. The work was later transferred to the office of the editor of Industrial and Engineering Chemistry, and with the increase in the work a managing editor was later employed. No record of returns was kept in the early history of the service, but beginning with 1918 clippings were collected through the regular channels and their total tabulated with the full realization that clipping bureaus are probably not more than 30 per cent. efficient, by which we mean that they probably collect not more than 30 per cent. of the articles printed on a given piece of news. The following figures as to cost and inches of publicity may be of interest: Present indications are that 1925 will see a further satisfactory increase in our return. We are proud of the record, not merely because it indicates extensive space having been devoted to chemistry, but because of the high character of the mediums which have seen fit to use our releases. While the editor of Industrial and Engineering Chemistry is the director of the News Service, the actual rewriting and placing of the stories is done by an experienced newspaper man who serves as managing editor. Special stories are frequently written, not only for given periodicals but in accordance with geographic interest in some new topic. There is no monetary return to the society for this work, but the chemists believe that the expenditure is amply justified, for many instances of returns in a broad sense can be noted and it is felt that the creation of a large body of public opinion sympathetic to the work of chemistry is certain to redound to the advancement of the science in America. The News Service was begun at a time when the press generally was inclined to print sensational stories, most of which were grossly inaccurate or mere figments of the imagination. There has been a decided decrease in this tendency and at present we are frequently solicited for information on topics before newspapers even write their own stories. Thanks to the News Service and to other educational efforts, it is not uncommon for special reporters to be assigned to the semi-annual meetings of the American Chemical Society. Other scientific organizations have from time to time engaged upon publicity campaigns and it is felt that the results of the American Chemical Society's efforts compare well with those obtained by similar organizations. H. E. HOWE, Editor PLANS FOR LUTHER BURBANK'S TENTATIVE plans have been made by Stanford University to take over and perpetuate the work of Luther Burbank, according to announcement made by William Gibbs McAdoo, member of the advisory board interested in the project. The plans contemplate the transfer of Burbank's experimental farm at Sebastopol to the control of Stanford University, which will set about raising an endowment fund sufficient to insure the carrying on of Burbank's work when the horticulturist ceases his labor of creating new plants and flowers and improving on present species. Burbank, for the past two years, has gradually been getting his affairs in shape so that his experimental farm might be taken over by some qualified institution. The proposal met with a ready response from Stanford University, owing to the warm personal friendship existing between Dr. David Starr Jordan and Luther Burbank. The announcement indicated that the university authorities had definitely taken up the project and would seek to raise the necessary endowment funds. In his statement, Mr. McAdoo said: For a period of fifty years Luther Burbank has been doing marvelous things in the field of horticulturethings that have conferred immeasurable benefits upon the human race. Mr. Burbank has done most of his epochal work on a thirteen-acre development farm at Sebastopol, Sonoma |