partment of philosophy has been dis- THE BOYDEN DEPARTMENT OF missed because his family relations are not approved. It is not alleged that he is immoral, and it is admitted that he is a good teacher and an able investigator, but his conduct and opinions are said to be subversive of the family. Whatever may be the merits of the case, the administrative methods do not show to advantage. tem. In the new state of Oklahoma "the best constitution in the world" has not provided an ideal educational sysIndeed the conditions approach opera bouffe too nearly to be taken quite seriously. The head of the state university, the heads of the normal schools and of other institutions have been dismissed and supplanted by southern democrats. At the university the question appears to be not whether a professor is an able teacher and investigator, but whether he is a good southern methodist and democrat, who does not dance. Such conditions are transient. The danger is that methods which can not be approved in politics and business may obtain such footing in our universities that they will no longer be centers of democratic individualism and of intellectual and moral leadership. THE HARVARD COLLEGE OBSERVATORY URIAH A. BOYDEN, a Boston inventor and engineer who died in 1879, bequeathed property valued at over $230,000 for "the establishment and maintenance of an astronomical observatory on some mountain peak at such an elevation as to be free, so far as practicable, from the impediments to accurate observations which occur in the observatories now existing, owing to atmospheric influences." The fund was transferred by the trustees named in the will to the Harvard College Observatory, which carried out the provisions by the establishment of the Arequippa Observatory in Peru. An illustrated account of this mountain observatory and of the researches that have been undertaken there was contributed to a recent volume of the MONTHLY by the director, Professor Solon I. Bailey. Prior to the foundation of the Arequippa Observatory in 1891, several expeditions were sent out to determine the conditions that would best fulfil the terms of Mr. Boyden's will, and an account of this preliminary work has just been published in "The Annals of the Harvard College The expedition to Peru arrived in Arequippa at the beginning of 1891, and a site for the observatory was selected on the crest of a ridge about 300 feet above the city. Here was erected an observatory in which there have been carried forward under the direction of Professor Bailey important observations on the southern stars. After working in the observatory established by Professor Lowell in Arizona, Professor W. H. Pickering concluded that neither dryness nor altitude is the important factor affecting the quality of the seeing, and, in order to study the problem further, an expedition to Jamaica was undertaken in 1899, where observations were made at several stations from the sea-level to an altitude of 2,300 feet. In a second Jamaica expedition the following year a horizontal telescope, with an 18-inch mirror and 15-inch lens, was erected at Mandeville. Professor Pickering concludes that elevation above the sea-level gives somewhat better definition, especially towards the horizon, and avoids dust and haze. A dry climate has advantages in its freedom from dew, cloud and fog, but does not give better definition than one that is moist. A low latitude has three advantages: The definition is better, the bodies to be observed pass near the zenith and a larger portion of the heavens is brought into view. THE HANOVER MEETING OF THE AMERICAN ASSOCIATION ON the invitation of Dartmouth College the American Association for the Advancement of Science will hold a special meeting at Hanover, N. H., from June 29 to July 3. The American Physical Society and the Geolog ical Society of America will meet with the association, and regular programs will be arranged only in physics and in geology. There will, however, be public lectures and numerous interesting excursions, and those able to attend may look forward to a pleasant visit to a typical New England college under the most favorable conditions. The railways offer rates of a fare and a third on the certificate plan, and excellent local arrangements are assured for the entertainment of visitors. Many members regret the transfer of the annual meeting of the association from the summer to the winter. It is certainly true that the large meetings in a city are likely to sacrifice the social pleasures to business efficiency and to neglect one of the main objects of the association-the diffusion of science. A meeting such as this at Hanover should be attractive to those who wish to meet their colleagues amid pleasant surroundings, and to those not professionally engaged in scientific work but interested in it. Men and women of this class are especially welcomed to the present summer meeting and may feel free to attend without being elected in advance to membership. Those who go are certain to find the meeting both pleasant and useful. SCIENTIFIC ITEMS WE record with regret the deaths of Dr. Heinrich Maschke, professor of mathematics in the University of Chicago; of M. Albert de Lapparent, the eminent French geologist; of Dr. K. Möbius, professor of zoology at Berlin, and of Dr. Pierre Jacques Antoine Béchamp, eminent for his researches in organic chemistry. THE house of representatives concurring with the senate and by a unanimous vote, has granted an annuity for life of $125 a month to the widows of the late Major James Carroll, surgeon, U. S. army, and the late acting assistant surgeon, Jesse W. Lazear, whose lives were sacrificed in the study of yellow fever in Cuba. THE POPULAR SCIENCE MONTHLY. AUGUST, 1908 THE HISTORY OF THE CONSERVATION OF ENERGY; THE AGE OF THE EARTH AND SUN BY PROFESSOR FLORIAN CAJORI COLORADO COLLEGE N the small town of Heilbronn, in Würtemberg, stands a monument erected to the memory of the physician, Robert Mayer. It was unveiled in 1892, just fifty years after the publication of Robert Mayer's first essay on the conservation of energy. His career as a scientific discoverer is marked by many pathetic incidents. After the study of medicine he was made sanitary officer on a Dutch vessel, bent for the East Indies. During the long ocean voyage on the slow sailing vessel he was left much to himself. He gave his leisure hours to the contemplation of scientific subjects. He had occasion to observe that, in tropical countries, blood taken from the veins of patients looks almost like arterial blood. He concluded that in the tropics less oxidation is necessary than in a cold climate, in order to maintain a uniform bodily temperature. There must be a quantitative relation between the amount of heat generated and the temperature in which we live. In cold, northern climates more heat must be developed for the maintenance of uniform bodily temperature. During the 219 days between February and September, 1840, spent on the water, Mayer dwelt in close intellectual communion with nature, and she gradually revealed to him one of her most precious secrets. Upon his return to Heilbronn he kept on thinking. A moving body is brought to rest by friction; heat appears. Has the motion disappeared into nothing? Has heat sprung out of nothing? If not, then there must be an equivalence between the heat generated and the motion destroyed. Causa aquat effectum, "Cause is equal to effect," became his favorite axiom. At first he thought that kinetic energy varied as the velocity. Later he recognized his error and perceived its variance with the square of the velocity. On June 16, 1841, he sent an essay embodying his new ideas for VOL. LXXIII.-7. publication in Poggendorff's Annalen, but the manuscript was not published nor was it returned to the author.2 Thirty-six years later it was found among the papers of Poggendorff. In 1842 Mayer pre pared a second short paper of seven pages and had the satisfaction of seeing it printed in Liebig's Annalen der Chemie. This was a happy time in his life, for at the very hour when he learned of the acceptance of his manuscript, he was bringing home his bride and presenting her to his aged parents. But it is one thing to secure the publication of a manuscript and quite another thing to get scientific men to read and study it. A new discovery necessitates a new language. A new language is not generally understood. The curse of Babel fell upon Mayer's paper: "Confound their language, that they may not understand one another's speech." Other papers were printed by Mayer as pamphlets in 1845 and 1848. Something of the personality of Mayer may be gained from the following stories. During a hurried meeting with Mayer in Heidelberg once, Jolly remarked, with a rather dubious implication, that if Mayer's theory were correct water could be warmed by shaking. Mayer went away without a word of reply. Several weeks later... he rushed into the latter's presence, exclaiming, “Es ischt so!" (It is so, it is so). It was only after considerable explanation that Jolly found out what Mayer wanted to say. Of metaphysics Mayer had no appreciation. Rümelin narrates that in 1841 Mayer borrowed from him a copy of Hegel's "Logik" and Hegel's "Naturphilosophie," but returned the books a few days later with the remark that he did not understand a word, and that he could not understand any part of it, were he to study it a hundred years.5 For years Mayer was unable to bring his great discovery to the serious attention of scientific men. Later there followed controversies on his rights of priority. A gloom fell upon him through the death of two of his children. His mind became seriously affected, and on May 26, 1850, he unsuccessfully attempted suicide by jumping from a second-story window. In 1851 he was placed in an insane asylum, where he was cruelly treated. Two years later he was set free, but he never again regained complete mental equilibrium. Such is the pathetic story of the first discoverer of the conservation of energy. 6 2" Mechanik der Wärme," von R. Mayer (ed. J. J. Weyrauch), Stuttgart, 1893, p. 16; "Kleinere Schriften u. Briefe," von Robert Mayer (ed. J. J. Weyrauch), Stuttgart, 1893, V., p. 99. 4 "Kleinere Schriften," p. 379. Mach in the Monist, Vol. 6, 1896, p. 171, copied in Cajori's “History of Physics," New York, 1899, p. 210. Several passages in this address are taken from this "History of Physics." 6 G. Rümelin, "Reden und Aufsätze," Freiburg i. B., 1881, p. 380. For a statement, by Clausius, explaining the manner in which Mayer's |