THE PARALLAXES OF THE STARS.

It needs only the most elementary conceptions of space, direction and motion to see that, as the earth makes its vast swing from one extremity of its orbit to the other, the stars, being fixed, must have an apparent swing in the opposite direction. The seeming absence of such a swing was in all ages before our own one of the great stumbling blocks of astronomy. It was the base on which Ptolemy erected his proof that the earth was immovable in the center of the celestial sphere. It was felt by Copernicus to be a great difficulty in the reception of his system. It led Tycho Brahe to suggest a grotesque combination of the Ptolemaic and Copernican systems, in which the earth was the center of motion, round which the sun revolved, carrying the planets with it.

With every improvement in their instruments, astronomers sought to detect the annual swing of the stars. Each time that increased accuracy in observations failed to show it, the difficulty in the way of the Copernican system was heightened. How deep the feeling on the subject is shown by the enthusiastic title, Copernicus Triumphans, given by Horrebow to the paper in which, from observations by Roemer, he claimed to have detected the swing. But, alas, critical examination showed that the supposed inequality was produced by the varying effect of the warmth of the day and the cold of the night upon the rate of the clock used by the observer, and not by the motion of the earth.

Hooke, a contemporary of Newton, published an attempt to determine the parallax of the stars, under the title of “An Attempt to Prove the Motion of the Earth,” but his work was as great a failure as that of his predecessors. Had it not been that the proofs of the Copernican system had accumulated until they became irresistible, these repeated attempts might have led men to think that perhaps, after all, Ptolemy and the ancients were somehow in the right.

The difficulty was magnified by the philosophic views of the period. It was supposed that Nature must economize in the use of space as a farmer would in the use of valuable land. The ancient astronomers correctly placed the sphere of the stars outside that of the planets, but did not suppose it far outside. That Nature would squander her resources by leaving a vacant space hundreds of thousands of times the extent of the solar system was supposed contrary to all probability. The actual infinity of space; the consideration that one had only to enlarge his conceptions a little to see spaces a thousand times the size of the solar system look as insignificant as the region of a few yards round a grain of sand, does not seem to have occurred to anyone.

Considerations drawn from photometry were also lost sight of, because that art was still undeveloped. Kepler saw that the sun might well be of the nature of a star; in fact, that the stars were probably suns. Had he and his contemporaries known that the light of the sun was more than ten thousand million times that of a bright star, they would have seen that it must be placed at one hundred thousand times its present distance to shine as a bright star. If, then, the stars are as bright as the sun, they must be one hundred thousand times as far away, and their annual parallax would then have been too small for detection with the instruments of the time. Such considerations as this would have removed the real difficulty.

The efforts to discover stellar parallax were, of course, still continued. Bradley, about 1740, made observations on γ Draconis, which passed the meridian near his zenith, with an instrument of an accuracy before unequalled. He thus detected an annual swing of 20″ on each side of the mean. But this swing did not have the right phase to be due to the motion of the earth; the star appeared at one or the other extremity of its swing when it should have been at the middle point, and vice versa. What he saw was really the effect of aberration, depending on the ratio of the velocity of the earth in its orbit to the velocity of light. It proved the motion of the earth, but in a different way from what was expected. All that Bradley could prove was that the distances of the stars must be hundreds of thousands of times that of the sun.

An introductory remark on the use of the word parallax may preface a statement of the results of researches now to be considered.

In a general way, the change of apparent direction of an object arising from a change in the position of an observer is termed parallax. More especially, the parallax of a star is the difference of its direction as seen from the sun and from that point of the earth’s orbit from which the apparent direction will be changed by the greatest amount. It is equal to the angle subtended by the radius of the earth’s orbit, as seen from the star. The simplest conception of an arc of one second is reached by thinking of it as the angle subtended by a short line at a distance of two hundred and six thousand times its length. To say that a star has a parallax of 1″ would therefore be the same thing as saying that it was at a distance of a little more than two hundred thousand times that of the earth from the sun. A parallax of one-half a second implies a distance twice as great; one of one-third, three times as great. A parallax of 0″20 implies a distance of more than a million times that of our unit of measure.

The first conclusive result as to the extreme minuteness of the parallax of the brighter stars was reached by Struve, at Dorpat, about 1830. In the high latitude of Dorpat the right ascension of a star can be determined with great precision, not only at the moment of its transit over the meridian, but also at transit over the meridian below the pole, which occurs twelve hours later. He, therefore, selected a large group of stars which could be observed twice daily in this way at certain times of the year, and made continuous observations on them through the year. It was not possible, by this method, to certainly detect the parallax of any one star. What was aimed at was to determine the limit of the average parallax of all the stars thus observed. The conclusion reached was that this limit could not exceed one-tenth of a second and that the average distance of the group could not, therefore, be much less than two million times the distance of the sun; if, perchance, some stars were nearer than this, others were more distant.

By a singular coincidence, success in detecting stellar parallax was reached by three independent investigators almost at the same time, observing three different stars.

To Bessel is commonly assigned the credit of having first actually determined the parallax of a star with such certainty as to place the result beyond question. The star having the most rapid proper motion on the celestial sphere, so far as known to Bessel, was 61 Cygni, which is, however, only of the fifth magnitude. This rapid motion indicated that it was probably among the stars nearest to us, much nearer, in fact, than the faint stars by which it is surrounded.

After several futile attempts, he undertook a series of measurements with a heliometer, the best in his power to make, in August, 1837, and continued them until October, 1838. The object was to determine, night after night, the position of 61 Cygni, relative to certain small stars in its neighborhood. Then he and his assistant, Sluter, made a second series, which was continued until 1840. All these observations showed conclusively that the star had a parallax of about 0″.35.

While Bessel was making these observations, Struve, at Dorpat, made a similar attempt upon Alpha Lyræ. This star, in the high northern latitude of Dorpat, could be accurately observed throughout almost the entire year. It is one of the brightest stars near the Pole and has a sensible proper motion. There was, therefore, reason to believe it among the nearest of the stars. The observations of Struve extended from 1835 to August, 1838, and were, therefore, almost simultaneous with the observations made by Bessel on 61 Cygni. He concluded that the parallax of Alpha Lyræ was about one-fourth of a second. Subsequent investigations have, however, made it probable that this result was about double the true value of the parallax.

The third successful attempt was made by Henderson, of England, astronomer at the Cape of Good Hope. He found from meridian observations that the star Alpha Centauri had a parallax of about 1″. This is a double star of the first magnitude, which, being only 30° from the south celestial pole, never rises in our latitudes. Its nearness to us was indicated not only by its magnitude, but also by its considerable proper motion.

Although subsequent investigation has shown the parallax of this body to be less than that found by Henderson, it is, up to the time of writing, the nearest star whose distance has been ascertained. The extreme difficulty of detecting movements so slight as those we have described, when they take six months to go through their phases, will be obvious to the reader. He would be still more impressed with it when, looking through a powerful telescope at any star, he sees how it flickers in consequence of the continual motions going on in the air through which it is seen and how difficult it must be to fix any point of reference from which to measure the change of direction.

The latter is the capital difficulty in measuring the parallax. How shall we know that a star has changed its direction by a fraction of a second in the course of six months? There must be for this purpose some standard direction from which we can measure.

The most certain of these standard directions is that of the earth’s axis of rotation. It is true that this direction varies in the course of the year, but the amount of the variation is known with great precision, so that it can be properly allowed for in the reduction of the observations. The angle between the direction of a star and that of the earth’s axis, the latter direction being represented by the celestial pole, can be measured with our meridian instruments. It is, in fact, the north polar distance of the star, or the complement of its declination. If, therefore, the astronomer could measure the declination of a star with great precision throughout the entire year, he would be able to determine its parallax by a comparison of the measures. But it is found impossible in practice to make measures of so long an arc with the necessary precision. The uncertain and changing effect of the varying seasons and different temperatures of day and night upon the air and the instrument almost masks the parallax. After several attempts with the finest instruments, handled with the utmost skill, to determine stellar parallax from the declinations of the stars, the method has been practically abandoned.

The method now practiced is that of relative parallax. By this method the standard direction is that of a small star apparently alongside one whose parallax is to be measured, but, presumably, so much farther away that it may be regarded as having no parallax. In this assumption lies the weak point of the method. Can we be sure that the smaller stars are really without appreciable parallax? Until recent times it was generally supposed that the magnitude of the stars afforded the best index to their relative distances. If the stars were of the same intrinsic brilliancy, the amount of light received from them would, as already pointed out, have been inversely as the square of the distance. Although there was no reason to suppose that any such equality really existed, it would still remain true that, in the general average, the brighter stars must be nearer to us than the fainter ones. But when the proper motions of stars came to be investigated, it was found that the amount of this motion afforded a better index to the distance than the magnitude did.

The diversity of actual or linear motion is not so wide as that of absolute brilliancy. Stars have, therefore, in recent times, been selected for parallax very largely on account of their proper motion, without respect to their brightness. It is now considered quite safe to assume that the small stars without proper motion are so far away that their parallax is insensible.

Ever since the time of Bessel the experience of practical astronomers has tended toward the conclusion that the best instrument for delicate measurements like these is the heliometer. This is an equatorial telescope of which the object glass is divided along a diameter into two semicircles, which can slide along each other. Each half of the object glass forms a separate image of any star at which the telescope may be pointed. By sliding the two halves along each other, the images can be brought together or separated to any extent. If there are two stars in proximity, the image of one star made by one-half of the glass can be brought into coincidence with that of the other star made by the other half. The sliding of the two halves to bring about this coincidence affords a scale of measurement for the angular distance of the two stars.

The most noteworthy forward steps in improving the heliometer are due to the celebrated instrument-makers of Hamburg, the Messrs. Repsold, aided by the suggestions of Dr. David Gill, astronomer at the Cape of Good Hope. The latter, in connection with his coadjutor, Elkin, made an equally important step in the art of managing the instrument and hence in determining the parallax of stars. The best results yet attained are those of these two observers and of Peter, of Germany.

Yet more recently, Kapteyn, of Holland, has applied what has seemed to be the unpromising method of differences of right ascension observed with a meridian circle. This method has also been applied by Flint, at Madison, Wis. Through the skill of these observers, as well as that of Brünnow and Ball, in applying the equatorial telescope to the same purposes, the parallax of nearly 100 stars has been measured with some approach to precision.

A rival method to that of the heliometer has been discovered in the photographic telescope. The plan of this instrument, and its application to such purposes as this, are extremely simple. We point a telescope at a star and set the clock-work going, so that the telescope shall remain pointed as exactly as possible in the direction of the star. We place a sensitized plate in the focus and leave it long enough to form an image both of the particular star in view and of all the stars around it. The plate being developed, we have a permanent record of the relative positions of the stars which can be measured with a suitable instrument at the observer’s leisure. The advantage of the method consists in the great number of stars which may be examined for parallax, and in the rapidity with which the work can be done.

The earliest photographs which have been utilized in this way are those made by Rutherfurd in New York during the years 1860 to 1875. The plates taken by him have been measured and discussed principally by Rees and Jacoby, of Columbia University. Before their work was done, however, Pritchard, of Oxford, applied the method and published results in the case of a number of stars.

One of the pressing wants of astronomy at the present time is a parallactic survey of the heavens for the purpose of discovering all the stars whose parallax exceeds some definable limit, say 0″1. Such a survey is possible by photography, and by that only. A commencement, which may serve as an example of one way of conducting the survey, has been made by Kapteyn on photographic negatives taken by Donner at Helsingfors.

These plates cover a square in the Milky Way about two degrees on the side, extending from 35° 50′ in declination to 36° 50′, and from 20h. 1m. in R. A. to 20h. 10m. 24s. Three plates were used, on each of which the image of each star is formed twelve times. Three of the twelve impressions were made at the epoch of maximum parallactic displacement, six at the minimum six months later, and three at the following maximum. The parallaxes found on the plates can only be relative to the general mean of all the other stars, and must therefore be negative as often as positive. The following positive parallaxes, amounting to 0″1, came out with some consistency from the measures:

Star, B. D., 3972Mag. 8.6R.A. 20h., 2m. 0s.Dec. +35°.5Par. +0″.11
Star, B. D., 3883Mag. 7.1R.A. 20h., 2m. 3s.Dec. +36°.1Par. +0″.18
Star, B. D., 4003Mag. 9.2R.A. 20h., 4m. 58s.Dec. +35°.4Par. +0″.10
Star, B. D., 3959Mag. 7.0R.A. 20h., 9m. 14s.Dec. +36°.3Par. +0″.10

Against these are to be set negative parallaxes of -0″.09, -0″.08 and several a little smaller, which are certainly unreal.

The presumption in favor of the actuality of one or more of the above positive values, which is created by their excess over the negative values, is offset by the following considerations: The area of the entire sky is more than 40,000 square degrees, or 10,000 times the area covered by the Helsingfors plates. We cannot well suppose that there are 1,000 stars in the sky with a parallax of 0″.10, or more without violating all the probabilities of the case. The probabilities of the case are therefore against even one star with such a parallax being found on the plates. Yet the cases of these four stars are worthy of further examination, if any of them are found to have a sensible proper motion.

On an entirely different plan is a survey just concluded by Chase with the Yale heliometer. It includes such stars having an annual proper motion of 0″.05 or more as had not already been measured for parallax. The results, in statistical form, are these:

2stars have parallaxes between+9″.20 and+0″.25.
6stars have parallaxes between+0″.15 and+0″.20.
11stars have parallaxes between+0″.10 and+0″.15.
24stars have parallaxes between+0″.05 and+0″.10.
34stars have parallaxes between+0″.00 and+0″.05.
8stars have parallaxes between-0″.05 and0″.00.
5stars have parallaxes between-0″.10 and-0″.05.
2stars have parallaxes between-0″.15 and-0″.10.
92,total number of stars.

It will be understood that the negative parallaxes found for fifteen of these stars are the result of errors of observation. Assuming that an equal number of the smaller positive values are due to the same cause, and subtracting these thirty stars from the total number, we shall have sixty-two stars left of which the parallax is real and generally amounts to 0″.05, more or less. The two values approximating to 0″.25 seem open to little doubt. We might say the same of the six next in the list. The first two belong to the stars 54 Piscium and Weisse, 17h., 322.

DISCUSSION AND CORRESPONDENCE.

THE MEETINGS OF THE AMERICAN ASSOCIATION.

The American Association for the Advancement of Science has a membership ranging from 1,900 to 2,000. Of this number probably at no one time was there an aggregate of 300 persons present at the recent annual meeting in New York.

When the Association meets in an Eastern city the attendance is generally twice if not three times as large as when it convenes in the West. So little was made of the recent meeting, locally or officially, that an intelligent resident of the city remarked: “Why, I intended to have attended some of the meetings, but seeing no reference in the daily papers, it entirely escaped my mind.”

Of the 2,000 members, about 800 are fellows; the 1,200 and more registered as members are, presumably, persons devoting little or no time to independent research along scientific lines, but persons who while not actively so engaged are more than ordinarily interested in the discussion of scientific topics. These have in the past paid dues and attended the meetings of the Association with more or less regularity. It is a question in the minds of some of the 1,200 if their attendance at the meetings is desired. Their membership, so far as it relates to the five dollars initiation fee and three dollars dues, is without question acceptable, and to persons reading papers in the various sections their presence is preferable to empty seats, but in view of the fact that during recent years the management of the Association has eliminated, so far as possible, the popular features of the general programme, the question is reasonably asked: “Does the management desire the attendance of the 1,200, or is their financial support all that is desired?”

It was stated some years ago that the purpose of the Association was to furnish not only an occasion for scientists to present original papers, but also to interest the public by holding the meetings annually in different parts of the country; but if attendance is not secured (by preparation and publication of interesting features of a programme) no great interest will be awakened by a meeting held in any part of the country.

I should like to suggest the following ways of increasing the interest of the meetings:

The general daily sessions might be made occasions of rare interest by the introduction of prominent men of science who would make at least brief remarks. This would make it possible for those who have limited time to become familiar with the faces of those whom they would like to know, and the little ‘sample’ of scientific thought thrown out would doubtless awaken desire for more.

It will be objected that the meetings of the council immediately preceding the general session prevent holding an official meeting at that hour. The public and the 1,200 would care little whether the session were official or unofficial so it were interesting and instructive.

The officers of the several sections could easily secure distinguished representatives of their respective sciences to give brief addresses followed by discussion, and thus the morning hour would prove an attraction to citizens and others who might be unable to attend the sessions following.

Again, citizens, where the meetings are held, would be pleased to provide excursions to points of local interest and extend social courtesies, if they were given in return the mental food in digestible form, with which the Association is so amply supplied.

It remains with the management to decide whether attendance shall be restricted to the few actively engaged in scientific pursuits, or whether it shall include the 1,200 and more who would be glad to avail themselves of the benefits of a programme suited to average scholarship and intellectual capacity.

There is no better medium for discussion of the above views than through the widely read pages of The Popular Science Monthly.

M. E. D. Trowbridge.

Detroit, Mich.

[The questions brought up by our correspondent have been carefully considered by all those who are interested in the American Association for the Advancement of Science. When the Association was founded fifty years ago there was no division into sections; the papers and discussions were intelligible and interesting to all members. At that time there were but few members, the scientific life of the country was small, and it was a privilege for a city to entertain the Association. But fifty years have brought changes in many directions. Specialization in science has become essential for its further progress, and it has been necessary to divide the Association into numerous sections and to found special societies. Hospitality can now only be provided at great expense, and Eastern cities no longer regard it as a privilege to entertain the numerous societies that gather within their hotels. The newspapers do not regard a meeting of the Association as an important event and will not devote space to it.

The Association must do the best it can to adapt itself to existing conditions. The recent meeting in New York had perhaps the largest attendance of scientific men of any in the history of the Association with the exception of the anniversary meeting two years ago, but New York City, especially in the month of June, is not a desirable place for social functions. It is not reasonable for a member interested in science as an amateur to expect to purchase for three dollars a week’s entertainment. His dues secure reduced railway and hotel rates; he can meet his friends and become acquainted with scientific men; he can always find on the programme papers that are of interest; he receives the annual volume of ‘Proceedings’ and the weekly journal, ‘Science,’ the cost of which is five dollars per year. But apart from these direct returns, he is surely repaid for membership by knowing that he is one of those who are united for the advancement of science in America.—Editor, Popular Science Monthly.]

THE COLOR RED.

To the Editor of The Popular Science Monthly: Mr. Havelock Ellis, in your August number, in ‘The Psychology of Red,’ says, ‘A great many different colors are symbolical of mourning ... but so far as I am aware, red never.’ The following may possibly be of interest in this connection:

“Our English Pliny, Bartholomew Glantville, who says after Isydorus, ‘Reed clothes ben layed upon deed men in remembrance of theyr hardynes and boldnes, whyle they were in theyr bloudde.’ On which his commentator, Batman, remarks: ‘It appereth in the time of the Saxons that the manner over their dead was a red cloath, as we now use black. The red of valiauncie, and that was over kings, lords, knights and valyaunt souldiers; white over cleargie men, in token of their profession and honest life, and over virgins and matrons.’”—(Dr. Furness’s Variorum. Merchant of Venice, p. 56.)

Chas. E. Dana.

University of Pennsylvania.

SCIENTIFIC LITERATURE.

MENTAL AUTOMATISM.

A recent work by Prof. Th. Flournoy, entitled ‘Des Indes à la Planète Mars,’[G] contains an account of a remarkable case of mental automatism, or sub-conscious personality. The subject is a young woman of about thirty years, apparently in good health, but always of a nervous and imaginative type. She developed tendencies towards lapses of consciousness, hallucinations and automatic actions; and these developed later, under the inspiration of spiritualistic séances, into a series of cycles, or automatic dramas, in which the medium speaks or writes and acts under the influence of several diverse subordinate personalities. In one of these cycles—which, it must be understood, are continued from one sitting to another, although in her intermediate normal life she knows nothing of what she has said or done in the trance—she becomes Marie Antoinette, and is said to act the part with unusual dramatic skill. In another and far more elaborate cycle the scene is transferred to the planet Mars, and the houses, scenery, plants and animals, peoples, customs and goings-on of the planet are described; sketches are made, and reproduced in the volume, of these extra-mundane appearances. Still more remarkable is the appearance of the Martian language, which in successive séances the subject hears, speaks, sees before her in space, and, in the end, even writes. From the mystery of Mars we are taken to the equally mysterious Hindu cycle; here the medium becomes an Indian princess of the fifteenth century, reveals her history and that of her associates in the Oriental life, tells of herself as Simandini; of Sivrouka, her prince, who reigned over Kanara and built in 1401 the fortress of Tschandraguiri. Wonderful to relate, these names are not fictitious, but are mentioned by one De Marlès in a volume published in 1828; the author, however, does not enjoy a high reputation as a historian. When occasional utterances of the Hindu princess are taken down, they are found in part to have close resemblance to Sanskrit words; while in her normal condition the medium is as ignorant of Sanskrit as she is of any language except French, and is entirely ignorant of both De Marlès and the people of India five hundred years ago. Surely this is a tale, bristling with mystery and improbability, which, if told carelessly or with a purpose, we should dismiss as a willful invention! M. Flournoy has been unusually successful in revealing the starting points of the several automatisms and of connecting them with intelligible developments of the medium’s mental life; and the manifestations, though they remain as remarkable examples of unconscious memory and elaboration of ideas, nowhere transcend these limitations. The sketches of Martian scenery are clearly Japanesque or vaguely Oriental; the Martian language is pronounced an ‘infantile’ production, and is clearly modeled after the French, the characters being the result of an attempt to make them as oddly different from our own as possible; the Sanskrit goes no farther than what one could get from a slight acquaintance with a Sanskrit grammar; and while there is a copy of De Marlès in the Geneva Library (where the medium lives), no connection can be established between either De Marlès or the grammar and the subject of this study. Most of this knowledge of these remarkable sub-conscious states would have been impossible were it not for ‘spirit control’ of one Leopold, who, in accordance with the doctrine of reincarnation which permeates the several cycles, was in his life the famous Cagliostro. By suitable suggestion, Leopold can be induced to make the entranced subject speak, write, draw, or interpret her strange messages from other worlds; and where Leopold says ‘nay’ all progress is stopped. This case has many analogies with other cases that have been recorded, but goes beyond most of them in the complexity and bizarre character of the unconscious elaborations and in the feats of memory and creative imagination which it entails. These accomplishments, it should be well understood, never appeared suddenly or fully developed, but only after a considerable period of subliminal preparation, and then only hesitatingly, and little by little, just as is the case with the acquisitions of normal consciousness; and all these acquisitions bear unmistakable marks of belonging to the same person. The special value of this account thus lies in the accuracy of the description and the success with which the account has been made thoroughly intelligible and significant.

[G] The book has just been published by the Harpers in an English version, under the title ‘She Lived in Mars.’

THE MOSQUITOES OF THE UNITED STATES.

Dr. L. O. Howard, the entomologist of the United States Department of Agriculture, has just published a bulletin entitled, “Notes on the Mosquitoes of the United States: Giving some Account of their Structure and Biology, with Remarks on Remedies.” The author has, for some years, been interested in the general subject of the biology of mosquitoes and of remedies to be used against them, and has brought together in this bulletin all the published and unpublished notes which he has been collecting during this period. The bulletin contains synoptic tables of all North American mosquitoes, prepared by Mr. D. W. Coquillett, and gives detailed facts regarding the geographical distribution of the different species mentioned. All the five North American genera are illustrated and full, illustrated accounts are given of the life history of the two principal genera, Culex and Anopheles, as studied in Culex pungens and Anopheles quadrimaculatus. The author calls special attention to the two genera of large mosquitoes, Psorophora and Megarhinus, and urges the importance of the study of these two genera, especially by physicians in the South, in regard to their possible relation to the spread of malaria. Considerable space is given to the subject of remedies, the principal ones considered being kerosene on breeding pools, the introduction of fish in fishless ponds, the artificial agitation of water and general community work. It is clearly shown not only that the mosquito may be, in many localities, readily done away with at comparatively slight expense, but that by careful work many malarious localities may be made healthy. The subject of mosquitoes and malaria is not discussed in the bulletin, which contains simply references to available papers on this subject, like the article by Dr. Patrick Manson, published in The Popular Science Monthly for July, the aim of the author being to bring together all available facts about the mosquitoes of the United States, in order to assist physicians who are studying the malarial relation from the point of view of local conditions.

THE PROGRESS OF SCIENCE.

The British, French and German Associations for the Advancement of Science have held their annual meetings in the course of the past month. In each of these countries and in most other European countries, as well as in America, there are migratory scientific congresses of the same general character. As these have grown up somewhat independently, they evidently meet a common need. Science cannot be advanced by a man working independently and in isolation. The printing press was essential to the beginnings of modern science, while at the same time it was usual for the scientific student to travel from place to place that he might learn and teach. Then in the seventeenth and eighteenth centuries, as the cultivation of science became more general, royal academies were founded. The Royal Society was established at London in 1660 under the patronage of Charles II., the Academy of Sciences at Paris in 1666 under Louis XIV., the Royal Academy at Berlin in 1700 under Frederick I., the Imperial Academy at St. Petersburg in 1724 under Peter the Great, and in other cities similar academies were founded under similar auspices. Then in the first half of the present century, as science continued to grow, the more democratic organizations for the advancement of science were established. The Society of German Scientific Men and Physicians was formed, chiefly through the efforts of Humboldt, in 1822; the Swiss Association in 1829, and the British Association in 1831. Our own Association was established in 1847, but was then the intergrowth of a society dating from 1840. These associations are significant of the spread of science among all the people. Science is no longer the concern of a few men under royal patronage, but the two great movements of the present century—the growth of democracy and the growth of science—have united for their common good.

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The British Association held its annual meeting at Bradford, beginning on September 5, under the presidency of Sir William Turner, professor of anatomy in the University of Edinburgh. We are able to publish, from a copy received in advance of its delivery, his presidential address, which traces the growth during the present century of knowledge regarding fundamental biological problems. The addresses of the presidents before the sections are usually written in a way that can be readily understood by those who are not specialists, and are consequently of greater interest to a general audience than some of the corresponding addresses before the American Association. The addresses at Bradford were: Before the section of mathematical and physical science Dr. Joseph Larmor discussed recent developments of physics with special reference to the extent to which explanation can be reduced purely to description; before the section of chemistry Prof. H. W. Perkin argued that radical changes should be made in the methods of teaching inorganic chemistry; before the section of geology Prof. W. J. Sollas spoke of the development of the earth, including the different critical periods in its history; before the section of zoölogy Dr. R. H. Traquair chose as his subject the bearing of fossil fishes on the doctrine of descent; before the section of geography Sir George Robertson considered certain geographical aspects of the British Empire and the changes brought about by improved means of intercommunication; before the section of economic science and statistics Major P. G. Craigie spoke of the use of statistics in agriculture; before the section of mechanical science Sir Alexander Binnie traced the historical development of science; before the section of anthropology Prof. John Rhys dealt with the ethnology of the British Isles, with special reference to language and folk-lore; before the section of botany Prof. Sidney H. Vines reviewed the development of botany during the present century. In addition to these addresses, evening discourses were given by Prof. Francis Gotch on ‘Animal Electricity,’ and by Prof. W. Stroud on ‘Range Finders.’ The usual lecture to workingmen was given by Prof. Sylvester P. Thompson, his subject being ‘Electricity in the Industries.’

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Bradford is situated in the coal regions, and is an industrial center devoted especially to the manufacture of textiles. More attention was paid to local interests than is usual at the meetings of the American Association. An exhibit was arranged to show the development of the elaborate fabrics from the unwashed fleeces, and another consisting of a collection of carboniferous fossils found in the neighborhood. A joint discussion was arranged between the sections of zoölogy and botany on the conditions which existed during the growth of the forests which supplied material for the coal, and there were a number of papers devoted to the coal measures and the fossils which they contain. Another subject connected with the place of meeting was the report of the committee on the underground water system in the carboniferous limestone. By the use of chemicals the course of the underground waters has been traced, including their percolation through rock fissures, and excursions were made to the site of the experiments. The local industries received treatment from several sides. Among other discussions of more than usual interest was that on ‘Ions’ before the physical section and on ‘What is a Metal?’ before the chemical section. Features of popular interest were accounts of adventures in Asia, Africa and the Antarctic regions, by Captain Deasy, Captain George and Mr. Borchgrevinck, respectively, and Major Ross’s paper on ‘Malaria and Mosquitoes.’

* * * * *

The French Association met at Paris in the month of August, with the numerous other congresses. General Sebert, in his presidential address, reviewed the progress of the mechanical industries during the century and devoted the last third of his time to a discussion of international bibliography, but without mentioning the International Catalogue which now seems to be an accomplished fact. The secretary of the Association, in his review of the year, devoted special attention to the joint meetings of the British and French associations last summer at Dover and Calais. The treasurer was able to make a report that the treasurers of other national associations will envy. The capital is over $250,000, and the income from all sources about $17,000, of which about $3,000 was awarded for the prosecution of research and to defray the cost of publication of scientific monographs. The national association for the advancement of science of Germany—the ‘Gesellschaft deutscher Naturforscher und Aerzte’—held its annual meeting at Aachen toward the middle of September. An account of the proceedings has not yet reached us, but the congresses are always largely attended and the combination of addresses of general interest, of special papers before the numerous sections and of social functions, is perhaps more effective than in any other society. It also appears to be a considerable advantage for medical men and scientific men to meet together.

* * * * *

While from the scientific point of view the present century has been notable for the development of national associations for the advancement of science, its latter decades have witnessed a growth of international scientific meetings which may be expected to become dominant in the twentieth century. There are at least one hundred congresses, having more or less reference to science, meeting at Paris during the present summer. Perhaps the most noteworthy of these, from the point of view of the organization of science, is the International Association of Academies, which was established last year at a conference held at Wiesbaden. In this Association eighteen of the great academies of the world, including our own National Academy of Sciences, have been united to promote the interests of science. Literature is also included—of the eighteen academies, twelve include in their scope both science and literature, four are devoted to science only and two to literature only. It is planned to have a general meeting every three years, to which each academy will send as many delegates as it regards as desirable, though each academy will have but one vote. In the interval between the general meetings, the business of the Association is to be directed by a committee, on which each academy is represented. The object of the Association is to plan and promote scientific work of international interest which may be proposed by one of the constituent academies, and generally to promote scientific relations between different countries. The Royal Society has proposed the measurement, by international coöperation, of an extended arc of the meridian in the interior of Africa.

* * * * *

The International Congress of Physics marked an advance owing to the fact that it met for the first time this year, and it appears that the proceedings were of unusual interest. This was in a large measure due to the arrangements of the French Physical Society, which did not simply make up a programme from a mass of heterogeneous researches, but secured some eighty reports on the present condition of physical science. These were prepared by many of the leading physicists of the world and when published—as they are about to be in three volumes—will set forth the condition of the science with completeness and authority. There were in all seven sections. In the first, which was concerned with measurement, in addition to numerous reports several propositions were brought forward in regard to units, which, being international in character, are specially fitted for discussion at such a congress. As the members, however, were not in most cases delegates from governments and scientific bodies, no definite action was taken, though some recommendations were made. The decimalization of time was not recommended, nor was the proposal to give a name to units of velocity and acceleration. It was, however, decided that the ‘Barrie’ be adopted as the unit of pressure. The other sections were for mechanical physics, for optics, for electricity, for magneto-optics and radio-activity, for cosmical physics and for biological physics. Among the reports and papers of commanding interest only two can be mentioned—the introductory address by M. Poincaré, discussing the relations between experimental and mathematical physics, and one by Lord Kelvin on the waves produced in an elastic solid traversed by a body acting on it by attraction or repulsion, in which, from a strictly mathematical point of view, he advanced the hypothesis of a movable atom surrounded by an immovable ether. In addition to various receptions, a session was held at the Sorbonne, where Messrs. Becquerel and Curie gave demonstrations with radio-active substances, and one at the Ecole Polytechnique, where President Cornu showed apparatus which had been used in the determination of the velocity of light. At the close of the congress the foreign secretaries placed a crown on the tomb of Fresnel.

* * * * *

While a physical congress was meeting at Paris this year for the first time, the Geological Congress, which was one of the first international congresses to be organized, held its eighth session, beginning on August 16. America, in spite of the number and importance of the inventions it has given to the world, has not as yet done its share for the advancement of physical science, but in geology it occupies a foremost place. It was natural, therefore, that while American physicists were scarcely represented on the programme of the Physical Congress, they occupied a prominent place on the programme of geological papers. Among the three hundred members present, the representation from America included Messrs. Stevenson, Hague, Osborn, Ward, Willis, White, Cross, Scott, Todd, Kunz, Choquette, Adams, Mathew and Rice, and they presented a number of the more important papers. M. Karpinsky, the retiring president, gave the opening address, which was followed by an address of welcome by M. Gaudry, the president of the congress. A geological congress can offer special attractions in the way of excursions, and these were admirably arranged on the present occasion—both the shorter excursions to the classic horizons in the neighborhood of Paris and the more extended ones that followed the close of the meeting. The guide for the twenty long excursions and numerous shorter trips, prepared by the leading French geologists, was an elaborately illustrated volume representing the present condition of our knowledge of French geology. The ninth geological congress will be held at Vienna three years hence.

* * * * *

The International Congress of Mathematics met for the second time at Paris, though there had been a preliminary meeting on the occasion of the Chicago Exposition. There were about two hundred and twenty-five mathematicians in attendance, including seventeen from the United States. M. Poincaré presided, and the vice-presidents, some of whom were not present, were Messrs. Czuber, Gordon, Greenhill, Lindelöf, Lindemann, Mittag-Leffler, Moore, Tikhomandritzky, Volterra, Zeuthen and Geiser. The sections and their presiding officers were as follows: (1) Arithmetic and Algebra: Hilbert; (2) Analysis: Painlevé; (3) Geometry: Darboux; (4) Mechanics and Mathematical Physics: Larmor; (5) Bibliography and History: Prince Roland Bonaparte; (6) Teaching and Methods: Cantor. Valuable papers were presented by M. Cantor on works and methods concerned with the history of mathematics, by Professor Hilbert on the future problems of mathematics and by Professor Mittag-Leffler on an episode in the life of Weierstrass, but the programme appears to have been not very full nor particularly interesting. Time was found for a half-day’s discussion of a universal language, but not to carry into effect the plans begun at Zurich three years ago for a mathematical bibliography. The next congress will meet four years hence in Germany, probably at Baden-Baden.

* * * * *

The untimely death of James Edward Keeler, director of the Lick Observatory, is a serious blow to astronomy and to science. Born at La Salle, Ill., forty-three years ago, he was educated at the Johns Hopkins University and in Germany. When only twenty-one years old he observed the solar eclipse of 1878, and drew up an excellent report. Three years later he was a member of the expedition to Mt. Whitney under Professor Langley, whose assistant he had become at the Allegheny Observatory, and whose bolometric investigations owe much to him. He became astronomer at the Lick Observatory while it was in course of erection, and in 1891 he succeeded Professor Langley as director of the Allegheny Observatory. He was called to the directorship of the great Lick Observatory in 1898. Keeler’s work in astrophysics, including his photographs of the spectra of the red stars and his spectroscopic proof of the meteoric constitution of Saturn’s rings, demonstrated what he could accomplish at a small observatory unfavorably situated. At Mt. Hamilton he was able in the course of only two years to organize thoroughly the work of the Observatory, and to adapt the Crossley reflector for his purpose, taking photographs of the nebulæ that have never been equalled. His discovery that most nebulæ have a spiral structure is of fundamental importance. It is not easy to overestimate what might have been accomplished by Keeler in the next twenty or thirty years, both by his own researches and by his rare executive ability, for it must be remembered that his genius as an investigator was rivaled by personal qualities which made his associates and acquaintances his friends.

* * * * *

Henry Sidgwick, late Knightbridge professor of moral philosophy at Cambridge, died on August 28, at the age of sixty-two years. There are usually not many events to record in the life of a university professor, but Sidgwick had an opportunity to prove his character when he resigned a fellowship in Trinity College because holding it implied the acceptance of certain theological dogmas. Liberalizing influences, however, were at work, of which he himself was an important part, and he was later elected honorary fellow of the same college, and in 1883 became professor of moral philosophy in the University. Sidgwick published three large works—‘Methods of Ethics’ (1874), ‘Principles of Political Economy’ (1883) and ‘Elements of Politics’ (1891)—in addition to a great number of separate articles. All these works, especially the ‘Ethics,’ show an intellect to a rare degree both subtle and scientific. There was a distinction and a personal quality in what he wrote that made each book or essay a work of art, as well as a contribution to knowledge. Those who knew Professor Sidgwick—and the writer of the present note regards it as one of the fortunate circumstances of his life that he was for several years a student under him—realize that the qualities of the man were even more rare than those of the author. His hesitating utterance, always ending in exactly the right word, but represented the caution and correctness of his thought. Subtlety, sincerity, kindliness and humor were as happily combined in his daily conversation as in his writings. It is said that he was never ‘entrapped into answering a question by yes or no,’ but his deeds and his influence were positive without qualification or limitation.

* * * * *

Friedrich Wilhelm Nietzsche, who died on almost the same day as Sidgwick, was also a writer on ethics and once a university professor, but the life and writings of the two men present a strange contrast. Where Sidgwick’s touch was light as an angel’s, Nietzsche trampled like a bull; the one was the embodiment of reason, caution, consideration and kindliness, the other represented paradox, recklessness, violence and brute force. Still Nietzsche deserves mention here, as his ethical views, based on the Darwinian theory of the survival of the fit, are not unlikely to be urged hereafter by saner men, and to become an integral part of ethics when ethics becomes a science. As a matter of fact, after resigning his professorship at Zurich, and even while writing his remarkable books, Nietzsche suffered from brain disease, and during the past eleven years his reason was completely lost.

INDEX.
NAMES OF CONTRIBUTORS ARE PRINTED IN SMALL CAPITALS.

[Transcribers’ Notes]

Punctuation, hyphenation, and spelling were made consistent when a predominant preference was found in this book; otherwise they were not changed.

Simple typographical errors were corrected; occasional unbalanced quotation marks retained.

Ambiguous hyphens at the ends of lines were retained.

Text uses both “angakok” and “angakut”; both retained.

Page [561]: Footnote ‘A’ was not referenced in the text; Transcriber attributed it to the title of the article.

Page [564]: Transcriber’s transliteration of Greek text shown in {curly braces}.

Page [575]: “milkrosomen” was printed that way.

Page [577]: Text uses both “Quan-si” and “Quansi”; both retained.

Page [580]: “grewsome” was printed that way.

Page [588]: “where in 1861” was printed that way, but likely is a misprint, perhaps for “1681”, as the next paragraph says that the plague disappeared from Europe in the eighteenth century.

[Pages 601], [602]: use both “Vallee” and “Vallée”; both retained.

Page [645]: “Moreever” was printed that way.

[Pages 669], [672]: “Wood’s Holl” was spelled that way when this issue of the magazine was published.

Page [672]: Missing page reference “76” added to “Vickery” entry, based on examination of the May, 1900 issue.

Links in the Index to the other five issues of Volume 56 will not function on all reading devices. When they do work, the first use in each session may lead to the beginning of the other issue, rather than to the specified page, but subsequent uses of any link in the same session should lead to the specified page. Links in the Index were not checked for accuracy, and the external links were not checked for validity. Due to the way two of those eBooks were prepared, links to the first article in the first two issues lead to the second page of those articles.

The other five issues of Volume 57 also are available at Project Gutenberg. The eBook numbers are [47219], [47227], [47238], [47261], and [47281].