Popular Science Monthly/Volume 75/November 1909/The Progress of Science
LORD KELVIN
The two great advances of modern science, perhaps the two most notable human achievements, are the doctrine of organic evolution and the doctrine of the conservation of energy. All the world has this year been celebrating the hundredth anniversary of Darwin's birth. William Thomson, born fifteen years later, occupies in the physical sciences a position almost equal to that of Darwin in the biological sciences. It is a striking fact that Great Britain should have produced these two great men in the same rank with Newton, by whom, and near Darwin, Kelvin nearly two years ago was buried in Westminster Abbey.
Thomson, like Darwin, appears to have been impressed with hereditary genius; his father was professor of mathematics and his brother professor of engineering. Unlike Darwin, typifying a distinction which seems to obtain between the mathematical sciences and the sciences of observation, Thomson was precocious. He matriculated at Glasgow University at the age of ten and attended his father's classes in mathematics. He published a mathematical paper of consequence before going to Cambridge as a student at the age of seventeen, and during his years as an undergraduate at Peterhouse, he published a number of papers on mathematical physics, which fully represented the direction and characteristics of the work which was continued for more than sixty years. He became professor of natural philosophy at the University of Glasgow at the age of twenty-two. At Cambridge Thomson rowed on his college boat and won the Calquhoun sculls, one of the chief athletic competitions of the university. He was one of the founders of the musical society of the university and played at its concerts.
This vigorous versatility was maintained to the end of his long life. The laying of the Atlantic cable, the fixing of units on which electrical engineering is largely based, the invention of electrical and other instruments, many of which were patented and produced a large fortune, seem almost incompatible with his theoretical work in mathematical physics, though it is true that his mathematical analyses were kept in close touch with actual facts. It seems odd to an American that he should have changed the name that had become familiar and famous, if indeed the peerage itself is worth while I when there are no heirs to whom it can be bequeathed. Darwin, to whom no peerage was offered but who bequeathed his name and a large measure of his scientific genius to his sons, seems in this respect to have enjoyed the better fortune. Kelvin visited this country three times and is associated with it both by his work on the Atlantic cable and by the fact that some of his most important theoretical deductions were made known in the form of lectures at the Johns Hopkins University.
An admirable account of Kelvin's scientific work has been contributed to the Proceedings of the Royal Society by Sir Joseph Larmor. From this monograph we reproduce three portraits—the two earlier ones on a reduced scale. It would be fortunate if it were possible to reproduce the lucid exposition of the development of Kelvin's contributions to science and their relations to the work of his predecessors and contemporaries.
In 1848 it was possible for Thomson to maintain the view that heat is a substance which may produce energy
William Thomson
in 1854. in falling to a lower temperature or may diffuse passively. But in 1844 Joule had made known his experiments establishing the transformation of heat into work, and in 1847 Helmholtz had published his classical memoir on the conservation of energy. Mayer's earlier paper was first brought to general notice by Joule in 1849. Maxwell published his first paper in 1856, but did not reach the electric theory of light until eight years later. Clausius presented his paper on the motive power of heat to the Berlin Academy in 1850. It was indeed a marvelous period in the history of physics. Among the giants of those days, Thomson stands almost or quite preeminent. His great paper on the dynamical theory of heat was published in 1851, and laid firmly the foundations of the scientific treatment of energy.
In 1849 Thomson published his memoir on the mathematical theory of magnetism, on which subject he had already written four years earlier. This was followed by his remarkable contributions to the theory of electricity and light. In later years his attention was directed to the structure of the ether and of matter. His limitation of the age of the earth gave much concern to geologists and biologists, which the more recent advances of physics has again relieved, though the episode was probably of advantage to the natural sciences.
Even in the briefest note, reference should be made to Thomson and Tait's "Treatise on Natural Philosophy," an epoch-making text, which Helmholtz translated into German, and to the admirable popular lectures which fill three volumes. 
William Thomson
in 1877. The contributions to electrical engineering have already been mentioned. Thomson was the leader in the advances by which steam is being supplanted by electricity.
An adequate appreciation of Kelvin's personality is quoted by Sir Joseph Larmor from the address of Lord Roseberry when installed as Kelvin s successor in the chancellorship of the University of Glasgow: "In my personal, intercourse with Lord Kelvin, what struck me was his tenacity, his laboriousness, his indefatigable humility. In him was visible none of the superciliousness or scorn which sometimes embarrass the strongest intellects. Without condescension, he placed himself at once on a level with his companion. That has seemed to me a characteristic of such great men of science as I have chanced to meet. They are always face to face with the transcendent mysteries of nature. . . . Such labours produce a sublime calm, and it was that which seemed always to pervade Lord Kelvin. Surely in an age fertile in distinction, but not lavish of greatness, he was truly great."
A PHOTOGRAPH OF HALLEY'S COMET
Edmund Halley, born in 1656, Savilian professor of geometry at Oxford and later Flamsteed's successor as astronomer royal, made notable contributions to astronomy and cosmical physics. He was the first to catalogue the stars of the southern sky; he studied the orbits of Jupiter and Saturn; he detected the acceleration of the moon's mean motion; he used the transit of Venus to determine the solar parallax; he discovered the proper motion of the fixed stars; he suggested the magnetic origin of the aurora borealis; he studied terrestrial magnetism and located magnetic poles; he surveyed the tides and coasts of the British Channel; he cooperated with Newton in the publication of the "Principia."
But outside the circle of astronomers, Halley's name is known because it is attached to a comet whose orbit he calculated and whose return he predicted. This was in 1682, when Halley computed its parabolic orbit, and comparing this with the imperfect observations of comets which had appeared in 1456, 1531 and 1607, concluded that each was the same body returning from the outer region of the solar system beyond the furthest known planet. He wrote: "Wherefore, if it should return according to our predictions about the year 1758, impartial posterity will not refuse to acknowledge that this was first discovered by an Englishman."
This was not only a great advance in astronomy and important in its relation to the theory of gravitation, but was a forward movement in the conception of the orderliness of the universe. Comets had been portents of war, pestilence and famine. It was indeed Halley's comet which appeared in 1066 at the time of the invasion of William the Conqueror and again in 1456 when Constantinople was besieged by the Turks and the crescent-shaped tail was a mighty omen.
Halley's comet duly appeared in 1759, somewhat retarded by the attraction of Jupiter and Saturn, its perturbations having been accurately calculated by the French astronomer, Clairaut. It appeared again in 1835 and is now once more rapidly approaching the earth and the sun, having passed the orbit of Jupiter in April last. It has been observed by Professor Max Wolf, of Heidelberg, and we are able to give here photographs taken by Mr. Oliver J. Lee with a two-foot reflector at the Yerkes Observatory. These are printed by the courtesy of Dr. Edwin B. Frost, director of the observatory and editor of the Astrophysical Journal, where they are also printed.
The plate of September 16 was taken with an exposure of 180 minutes, standard central time of mid-exposure being 14h 5m (2:45 a.m. Sept. 17). The comet's position, as measured on the plate, was R.A. 6h 18m 56s, Dec. + 17° 9′ 23″. The plate of September 17 was exposed for 130 minutes, mid-exposure at (central standard time) 14h 10m (2:10 a.m. Sept. 18). The right ascension had increased by 4s, and the declination had decreased by 23″. The arrows indicate the position, and also the components of the direction of the comet's motion.
The original negatives are magnified about ten times, and the scale of the I pictures here is about 8″.5 to the milli, meter, or 3.5 minutes of arc to the inch; in other words, the width of each picture is about one seventh of a degree. The new Lumière "Sigma" plates were used, a fresh and clean 
emulsion having been provided by the manufacturers. The faintness of the comet on the plate of September 17 was due to the poor sky, and not to any change in the comet's brightness. The brightest star shown in the pictures, near the left-hand edge, slightly above the center, is of magnitude 8.7, or about ten times fainter than the limit of naked-eye visibility. Stars at least as faint as the seventeenth magnitude, or twenty-five thousand times fainter than naked-eye visibility, are shown on the original negatives, and the comet's brightness must have been considerably less than this, more accurate determinations being now in progress at the hands of Mr. Parkhurst. The comet was first observed visually by Professor Burnham, with the forty inch telescope, on September 15. It was also observed visually by Professor Barnard on September 17 and several subsequent nights. Professor Barnard's visual estimate of the comet's brightness at his last observation before the moonlight interfered, on the early morning of September 27, was that it was of magnitude 14 or 14.5. His measures indicated a diameter of about 10", but the object was without definite boundary.
The comet will be visible to the naked eye early next year and will attain its greatest brightness in the month of May.
SCIENTIFIC ITEMS
We record with regret the death of Dr. Washington Irving Stringham, professor of mathematics in the University of California; of Dr. Leonard Pearson, dean of the Veterinary School the University of Pennsylvania, and of professor Anton Dohrn, the eminent zoologist, founder and director of the Naples Zoological Station.
Dr. A. Lawrence Lowell was installed as president of Harvard University on October 6 and Dr Ernest Fox Nichols was installed as president of Dartmouth College on October 14. The inaugural addresses, which are devoted to the condition of the American college are printed in Science for October 15.
Dr. Edmund C. Sanford, A.B. (California, '83), Ph.D. (Johns Hopkins, '88), professor of experimental psychology in Clark University, has been elected president of Clark College to succeed the late Carroll D. Wright.—Dr. J. F. Anderson has been appointed director of the Hygienic Laboratory, Washington, D. C, to succeed Dr. M. J. Rosenau, who retires from the Public Health Service to accept a professorship of preventive medicine and hygiene at Harvard University.
Dr. Ira Remsen, president of the National Academy of Sciences, has consented, at the request of Dr. H. F. Osborn, president of the American Museum of Natural History, and Mr. Archer Huntington, president of the American Geographical Society, to appoint a scientific commission to examine the records of Lieutenant Peary and Dr. Cook, in case they are ready to present them to such: a commission. Lieutenant Peary has accepted the suggestion.
Professor Georg Lunge, the eminent chemist of Zurich, was presented on September 19 with a gold medal bearing his portrait and the sum of 40,000 francs to celebrate his seventieth birthday and the jubilee of his doctorate. Chemists were present from many countries and addresses were delivered by a number of delegates. Professor Lunge in his reply announced his intention of giving the money to the Polytechnic Institute for the aid of students of chemistry.—On the occasion of the recent Leipzig celebration Dr. Wilhelm Wundt, the eminent psychologist, who made the principal address, was given the title of excellency. He was also made an honorary citizen of the city of Leipzig.
At the meeting of the Chemists' Club, New York, held on October 8, it was announced that a Chemists' Building Company had been organized, for the purpose of acquiring a plot of ground and erecting thereon a large scientific building, the lower floors of which are to be rented to the Chemists' Club on a long lease, to contain scientific meeting rooms, a library and a museum, as well as the ordinary facilities required by a social organization, including sleeping apartments for its members. The upper floors of the building are to be leased for scientific offices and laboratories.
Yale University has received from Mr. William D. Sloane and Mr. Henry T. Sloane the sum of $475,000 to build, equip and endow a physical laboratory.—The University of Pennsylvania proposes to erect during the coming year a building for its graduate school, costing $250,000.—The Pratt Institute of Brooklyn has received the sum of $1,750,000 from Mr. Charles M. Pratt, son of the founder and now its president, and from his five brothers and his sister, Mrs. E. B. Dane.