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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.
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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.
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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.
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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.