# Popular Science Monthly/Volume 61/June 1902/The Progress of Science

(1902)
The Progress of Science

THE PROGRESS OF SCIENCE.

LORD KELVIN IN AMERICA.

The ways of a democracy must appear past finding out to those who observe us from a distance. When Prince Henry visited the United States the newspapers devoted half their space to the event; yet it might be supposed that Emperor William, the energetic, would come to America, if he wished to extend to us the social etiquette of foreign nations, and that we should regard with slight interest a lesser royal guest. When the greatest living Anglo-Saxon man of science visits us, the event passes unnoticed by the general public; yet Lord Kelvin's contributions to the applications of electricity, and especially his connection with the trans-Atlantic cable, might be expected to attract general attention.

Lord Kelvin has, of course, been cordially welcomed by his scientific colleagues. He accepted an invitation extended by wireless telegraphy to attend the installation of President Butler at Columbia University, and on April 21 he was entertained at the University by the national societies concerned with the physical sciences Professor F. B. Crocker presided, and addresses of welcome were made by President Butler; by Professor Elihu Thomson, representing the American Institution of Electrical Engineers; by Professor A. G. Webster, representing the American Physical Society, and by Professor R. S. Woodward, representing the American Association for the Advancement of Science and other scientific societies. Lord Kelvin in his reply referred to his previous visits to America. He first landed on this continent in 1866 in Newfoundland when the work of Mr. Field in connection with the trans-Atlantic cable was of special importance; ten years later he came to the Centennial Exposition, where he saw the telephone invented by Mr. Bell; in 1884 he found the electric light of Mr. Edison; in 1897 he saw the electrical industries of Niagara Falls. Lord and Lady Kelvin were very cordially greeted and applauded by the 2,500 people present. In addition to the reception at Columbia University, Lord Kelvin was entertained at Cornell University, at the University of Rochester—the main object of his visit was to attend a meeting of the Kodak Company at Rochester—and at Yale University, where the degree of Doctor of Laws was conferred on him. In conferring this degree, President Hadley said: "You have joined the different regions of the earth by your investigations of the submarine telegraph; you have joined the different realms of human thought by your contributions to physical theory."[1]

THE METRIC SYSTEM IN THE UNITED STATES.

A bill is now before Congress adopting the metric system of weights and measures as the standard in the United States. Though it does not seem likely that the bill will be passed during the present session it has been recommended by the committee on coinage, weights and measures, and the chances of its adoption seem more favorable than ever before. The bill requires the departments of the government to use the metric system after the beginning of the year 1904 and makes it the legal standard in the United States after January 1, 1907. The house committee has given a number of hearings on the subject, published in a pamphlet of 240 pages, and has drawn up a careful report. This report covers familiar ground, but in an unusually clear and straightforward manner. The attitude of Washington, Jefferson and Adams is referred to, and the history of the metric system of weights and measures is briefly reviewed. It is pointed out that the adoption of a decimal system of coinage in the United States was one of the strongest influences leading to the adoption of the metric system by France, and that Great Britain and the United States are practically the only non-metric countries. The weights and measures of Great Britain and the United States are not identical as is generally supposed, and there is no chance whatever that either system will become a universal system. The metric system has become necessary for scientific work; it would decrease the cost and labor of education; it would give unity to our manufactures, and is almost necessary for the extension of our commerce. The admitted expense and trouble involved in the adoption of the system are less, as has been shown in other countries, than is feared, and in any case the longer the adoption is delayed the greater will be the difficulty. The scientific, manufacturing and commercial interests of the country are under great obligations to Mr. John F. Shafroth, who, as chairman of the house committee on coinage, weights and measures, has devoted much careful attention to the subject.

THE CAUSES OF VOLCANIC ERUPTIONS.

The recent volcanic outbreaks in the Lesser Antilles have naturally aroused much popular and scientific interest in these geological phenomena and have made a brief statement of current and accepted explanations of them a matter of interest. All these manifestations of heat are derived from the great stores which exist in the interior of the earth. The consideration of them and of the known increase of temperature with depth led earlier geologists to believe that the earth possessed a heated molten core and a cold and relatively thin exterior shell. But as further investigation developed correct conceptions of the rigidity of the globe in resisting strains produced by its rotation and the attraction of other heavenly bodies for its mass; and as the elevating effect upon the fusing points of rocks of an increase of pressure was realized, it was seen that the earth is practically solid clear through and that local reservoirs of molten rock beneath volcanic districts are alone admissible. That local reservoirs exist seems quite well established, and that the rock is sufficiently fluid to enable complex parent magmas to break up into various differential products is the latest result of the investigation of eruptive areas. Volcanoes are moreover arranged along great lines of geological disturbance and fracture as shown in the accompanying illustration. The fractures are naturally the conduits through which the great tension of the internal molten masses is eased by eruptions. The immediate propulsive force which drives the lava to the surface is the next topic of importance which challenges attention. Some geologists believe that the contraction of the globe and the sinking of one side of the great fractures above referred to force out the lava as juice might be squeezed through a rent in an orange. Others, however, attribute the propulsion to the vapors which are held dissolved or occluded in the lava and which are so much in evidence at times of eruption. The frightful explosions and the vast exhibitions of power which they present give much force to this conception. Imagine then a rising tide of lava. As it forces its way through the conduit it spreads earthquake shocks abroad. Reaching the surface its dissolved vapors explode with greater and greater violence and scatter tuffs and breccias over the neighboring country. They may rend

Map of Volcanic Disturbances. (From Bonney's 'Volcanoes' Putnam's Science Series.)

 |||| Signifies Extinct Volcanoes. ${\displaystyle +}$ Signifies Active Volcanoes but is not intended to indicate either the number or the exact position. - - - - - - Signifies the probable direction of lines of weakness in the earth's crust.

the crater and set loose floods of lava. As the energy expends itself, the violence declines and disappears. The volcano then yields only hot springs and gaseous emissions called fumaroles, until it is stone-cold.

SOME FACTS AND FIGURES CONCERNING THE EARTH.

The earth is easily the most interesting and the best known to us of the bodies of the universe which have been subjected to scientific investigation. Not only do we know more of the earth than of any other member of the solar system, but we know more of the earth than of any of the smaller bodies which have been studied minutely in laboratories. It is true, of course, that a few bodies, like standards of length and mass, have been determined with great precision with respect to one or two of their properties; but our knowledge of the earth includes many of its properties, and some of them are known with a precision only surpassed by that of the standards referred to.

The surface of the earth is closely that of an oblate spheroid whose axes are known within about the hundred thousandth part, a precision near the limit possible in laboratory measurements of such bodies as inch ball-bearing spheres now made with wonderful exactness for commercial purposes. The surface and volume of this spheroid are found to be in round numbers two hundred million square miles and two hundred and sixty thousand million cubic miles respectively; and these numbers are known with an accuracy far surpassing that of the measured areas, for example, of the most valuable city properties, which are relieved of the necessity for precise measurement by the legal phrase, 'be the contents of the same more or less.' The magnitude of the work which has led to these results may be appreciated to some extent if one considers seriously how one would measure an area of two hundred million square miles with an error not greater, say than one fifty-thousandth part.

Less definite but of a higher order of magnitude are the figures expressing the quantity of mass of the earth, or what is sometimes designated by the scientifically meaningless phrase 'the weight of the earth.' We all have a tolerably clear idea of the mass in a ton of coal, but few of us are fitted to realize the nearly equally definite quantity of the earth's mass, which is in round numbers six thousand six hundred million million million tons. Of this total mass, the atmosphere, whose lenticular-shaped envelope includes a volume about one hundred and fifty times that of the solid part of the earth, contributes somewhat more than one millionth part, a small fraction of the whole, but yet millions of millions of tons in amount.

The regularity of rotation of the earth, or its constancy as a timekeeper, is no less surprising when expressed in numbers. The variation from day to day in the time of rotation is probably less than the hundredth of a second, or no greater, say, than the ten-millionth part of a day. Our best clocks and chronometers, and they are marvels of mechanical perfection, fall far short of this degree of constancy. Equally remarkable for stately regularity are the precession and nutation of the earth, by reason of which its axis of rotation describes a slightly fluted cone in the heavens, making one complete revolution in the leisurely interval of about twenty-six thousand years and thus rendering it essential for us to change pole stars from time to time. And still more noteworthy are the lately discovered minute wabblings of the earth with respect to its axis of rotation, whereby the latitude of a place varies from month to month, running through a lesser cycle in about fourteen months and through a greater cycle in something like seven years. That these recondite phenomena have been disentangled and reduced to precise numerical statement is at once conclusive evidence of method in the madness of terrestrial motions and of exquisite refinement in astronomical science.

The much discussed question of the age of the earth may now be said to have risen from the level of figures of speech to the higher plane of numerical expression. We are not able, and we may never be able, to assign the age of the earth in years, or in thousands of years as our most respected teachers have done in the recent past; but we may say without fear of anything worse than literary contradiction that the age of the earth must be reckoned in millions of years. Probably some hundreds of millions of years have elapsed since the earth became habitable to organic forms. Nature has plenty of time for her operations; and old as the earth must be in comparison with the centuries of human affairs, it is still active with the energy manifested in the earliest geological times. The processes of erosion and sedimentation, and that of secular contraction from loss of internal heat, are still asserting themselves occasionally (frequently, if a million years be used as the time unit) by such appalling outbursts as that which has just overwhelmed St. Pierre. And these processes, though fraught with calamities here and there to our race, must go on for millions of years yet to come.

BIOGRAPHIES OF EMINENT CHEMISTS.

Within the last few years several particularly attractive biographies of distinguished chemists have been issued as volumes of the 'Century Science Series,' edited by Sir Henry E. Roscoe; they differ from other works in the same line in that they portray the men and their careers more graphically and concisely, and embody at the same time the results of the latest researches. One of these, written by Roscoe himself, bears the title 'John Dalton and the rise of Modern Chemistry' (New York, 1895).

Half a dozen memoirs of the Founder of the Atomic Theory had previously appeared, the most noteworthy being those by W. C. Henry (1854), by R. Angus Smith (1856), and by H. Lonsdale (1874). The first named forms one of the volumes printed for the Cavendish Society, the second includes a History of the Atomic Theory from the days of the Greeks to the time of Dalton, and is embellished with the most satisfactory of the printed portraits.

Roscoe's charming work is enlivened with facsimiles, extracts from letters, papers and books by Dalton, reminiscences by contemporaries, appreciations by later chemists and amusing anecdotes, the whole so simply and yet so vigorously written as to make a delightful narrative. There has always been much speculation as to the mental processes which led Dalton to conceive of the great theory indissolubly connected with his name, and this problem has only been quite recently solved by the discovery in the rooms of the Literary and Philosophical Society of Manchester (where the whole of the experimental work was carried on by Dalton) of his laboratory and lecture notebooks, in a number of volumes. It has been supposed that it was the experimental discovery of the law of combination in multiple proportions that led Dalton to the idea that chemical combination consists in the approximation of atoms of definite and characteristic weight, the atomic theory being thus adopted to explain the facts ascertained by chemical analysis. But an examination of these newly discovered manuscript notes shows that he arrived at these ideas from purely physical considerations along the line of the Newtonian doctrine of the atomic constitution of matter; he conceived of chemical combination as taking place between varying numbers of atoms of definite weight, and then succeeded in confirming this view by the results of analyses made both by other chemists and by himself. This is precisely the inverse of the commonly accepted supposition.

This view of the genesis of Dalton's Atomic Theory has been published in a small volume with the title: 'A New View of the Dalton's Atomic Theory,' edited by Sir Henry E. Roscoe and Arthur Harden (London, 1896). The work contains also documents and letters by Dalton not previously published. No student of Dalton or of the atomic theory can afford to ignore this important contribution to history of chemistry.

Another volume in the Century Science Series deals with Sir Humphry Davy, poet and philosopher, and is by T. E. Thorpe (London, 1896). In preparing this Dr. Thorpe made use of the memoir on Davy by Dr. Paris (London, 1831), and that by Sir Humphry's brother, John Davy (London, 1858), as well as of contemporary periodicals, letters, and diaries of his friends and brother scientists. The first named of the earlier biographies has been found inaccurate as to matters of fact and extravagant in laudation; the second is written with candor and greater simplicity, and on the whole is more reliable. Dr. Thorpe's portrayal of the brilliant chemist is more correct and satisfactory; Davy's versatility is well brought out, his poetical writings, his philosophic studies, and his scientific labors, as well as his character as a man. Davy's discovery of the physiological effects of breathing 'laughing gas,' as it was called, made him conspicuous in the world of science when he was twenty-one years of age, and this prominence he maintained by his genius throughout life; at the age of thirty he isolated the metals of the alkalies, at the age of thirty-eight he invented the safety-lamp, at the early age of fifty-one he died.

One of Sir Humphry's most notable discoveries, certainly that which proved of the greatest benefit to mankind and to the progress of civilization (not excepting the safety-lamp), was Michael Faraday. The biography of this simple-minded and remarkable scientist, by Silvanus P. Thompson, forms another volume of the Century Science Series; two others deal with Justus von Liebig (by W. A. Shenstone) and with Pasteur (by Professor and Mrs. Percy Frankland), but the limited space at our command forbids further details.

Less brilliant, but no less patient an investigator was the Scotch chemist, Thomas Graham, whose career was very nearly conterminous with that of Liebig, and differed but little from that of Faraday. The Life and Works of Thomas Graham was prepared by Dr. Angus Smith, but owing to his feeble health (which terminated in death) the volume was edited by J. J. Coleman (Glasgow, 1884). Graham's life is rather inadequately depicted, but the book is enriched by more than sixty of his letters interspersed by brief notes of his contributions to science as well as by abstracts of all his published papers; among the latter may be mentioned those on the diffusion of gases and of liquids (1838-1863) and on the occlusion of hydrogen by metals (1868). In spite of his confining duties as Master of the Royal Mint, Graham found time for many other important investigations and for preparing a text-book which afterwards in connection with Friedrich Julius Otto became the celebrated and voluminous German 'Lehrbuch der Chemie' that passed through several editions.

The discovery of argon, and of other constituents of the atmosphere by Lord Rayleigh and William Ramsay in 1895 aroused renewed interest in the eccentric philosopher Cavendish, who narrowly escaped anticipating the recent discovery. The life of the Honorable Henry Cavendish, 'le plus riche de tous les savants et probablement aussi le plus savant de tous les riches'[2] was published by the Cavendish Society in 1851, being edited by Dr. George Wilson; Cavendish's electrical researches were edited by J. Clerk Maxwell from original manuscripts in the possession of the Duke of Devonshire, and published in 1879; since then there has been no important monograph concerning him.

THE ORIGIN OF THE HUMAN SPECIES.

The discovery by Dubois of the much discussed remains of Pithecanthropus erectus in a situation which seems to indicate for them a late Pliocene horizon, has reawakened interest in the phylogeny and antiquity of man, and has led to a reexamination of some of the more interesting prehistoric remains. The Neanderthal skeleton has recently been carefully studied by Schwalbe and Klaatsch and minute comparisons have been made with recent races on the one hand, with the Spy remains and Pithecanthropus on the other and also with the recent anthropoids.

The results of these studies have demonstrated a great similarity between the Neanderthal and Spy skeletons and the possession by these of so many peculiarities which lie beyond the limits of variation in recent human races, that it has been thought necessary to recognize them as representatives of a distinct species of Homo, the H. Neanderthaliensis. Of this species we know at least three individuals and possibly more, and it seems certain that it is quite distinct from the Pithecanthropus, the skull characters of this Javanese form placing it on a much lower level than the Neanderthal-Spy skulls, and showing a more pronounced approach toward generalized anthropoid condition than is to be seen in the European skulls. There is, however, an enormous gap between even Pithecanthropus and the recent anthropoids, and, indeed, it seems certain that the latter cannot be regarded as coming into the direct line of human descent, but both these and existing human races must trace back to a common ancestor, whose characteristics are perhaps indicated in the cranial peculiarities of young anthropoids.

If this be the case it would seem that the origin of the human race must be referred back to a period antedating considerably the horizons to which H. Neanderthaliensis and Pithecanthropus belong. The former is assigned by Klaatsch to the first interglacial period, at the close of the Chelléan era, while the latter seems to pertain to the late Pliocene, and the divergence of form which led to the genus Homo would accordingly seem to be referable to the early Pliocene or possibly even to the Miocene period.

SCIENTIFIC ITEMS.

We regret to record the death of Henry Morton, the eminent engineer, president of Stevens Institute of Technology since its foundation in 1870.—J. Sterling Morton, ex-Secretary of Agriculture, died on April 27.—The death is announced of Mr. Patrick T. Manson, son of Dr. Patrick Manson, on Christmas Island, whither he had gone to investigate the cause and treatment of beriberi, on behalf of the London School of Tropical Medicine.—M. Alfred Cornu, the eminent physicist, since 1867 professor at the Ecole polytechnique, Paris, has died at the age of sixty-one years.—M. Emile Renou, founder and director of the Meteorological Observatory at St. Mauri, died in Paris on April 7, aged eighty-seven.—M. Henri Filhol, professor of paleontology at the Jardin des Plantes, Paris, and the author of numerous important contributions to this science, has died at the age of sixty years.—Immanuel Lazarus Fuchs, since 1884 professor of mathematics in the University of Berlin, died on April 26 at the age of sixty-eight years.—Dr. E. von Pfleiderer, professor of philosophy at Tübingen, has died at the age of sixty years.

Dr. Alexander Agassiz has been appointed director of the Museum of Comparative Zoology, and Dr. A. E. Kennelly, of Philadelphia, has been appointed professor of electrical engineering at Harvard University.—The Hon. Carroll D. Wright, commissioner of labor, has been appointed president of the collegiate department of Clark University. It is understood that Mr. Wright will not, for the present at least, resign his position under the government or his work at Columbian or Catholic University.—The Secretary of War has sent to the House a recommendation that Surgeon-General Sternberg be granted the rank of major-general before his retirement on reaching the age limit June next.—The University of Edinburgh has conferred its LL.D. on Professor William James, the eminent psychologist of Harvard University, and on Dr. J. G. Schurman, president and formerly professor of philosophy at Cornell University.

Dr. Daniel Coit Gilman, president of the Carnegie Institution, sailed for Europe on April 17, with a view to studying foreign scientific institutions.—Professor Solon I. Bailey, of the Harvard Astronomical Observatory, is about to leave for the observatory's branch at Arequipa, Peru, where he will especially study the planet Eros. Dr. W. H. R. Rivers, of Cambridge University, will shortly start on an expedition for the psychological study of the Todas of southern India on the lines of his work in Torres Straits.—Professors Victor C. Vaughan and Frederick G. Novy of the medical department of the University of Michigan will leave for Asia about the middle of June to investigate tropical dysentery.—Dr. J. L. Wortman, of the Peabody Museum of Yale University, will be in the West until September, exploring the fields in Dakota, Wyoming and the Bad Lands, where the late Professor Marsh made his important paleontological discoveries.—Ernst A. Bessey, in charge of the Section of Seed and Plant Introduction in the United States Department of Agriculture, has been detailed to proceed to Russia, the Caucasus, and Turkestan for the purpose of securing certain seeds of forage and cereal plants. He is to sail on July 2.—An expedition to northern Brazil will be sent out by the Austrian Government in the autumn under the direction of Dr. M. Steindachner, curator in the Vienna Museum of Natural History.

In accordance with our plan of reprinting in each number of The Popular Sclence Monthly an article which appears to be of special interest and which is inaccessible to most of our readers, we published last month part of a paper on the physiological effect of electrically charged molecules by Professor Jacques Loeb, of the University of Chicago, originally contributed to The American Journal of Physiology. The consent of the editor of the journal and of Professor Loeb was asked, but Professor Loeb wrote that he would prefer not to have the article republished, as owing to the misrepresentation that his work had suffered in the daily papers and in the magazines, he preferred to have his researches published only in technical journals. Unfortunately Professor Loeb's letter was not received until after the form had been printed, and we can only express our regret that the extracts were reprinted without his approval.

A. Wall

1. The portrait of Lord Kelvin given as a frontispiece is from an etching made for Minerva by Professor Hubert Herkomer.
2. The richest of all savants and the most eminent of all the rich.