ADDRESS OF PROFESSOR CHARLES A. YOUNG, VICE PRESIDENT, SECTION A. FELLOW MEMBERS OF THE ASSOCIATION LADIES AND GENTLEMEN :— I propose at this time, in fulfilling a duty which the honor you have conferred upon me imposes, to choose my subject in accordance with the suggestions of the season, and to speak briefly of the History of Astronomy in the United States during the past Century, its present condition, needs and prospects. I regret exceedingly that ill health, and the pressure of other imperative duties have prevented me from giving the time and research really necessary for the preparation of anything worthy of the subject, the occasion, and the audience, but such as I have I offer, with the hope that you will extend to me your kind consideration and indulgence. Astronomy is the oldest, the most mature and beautiful of the whole family of Sciences-that immortal Sisterhood whose loveliness and vigor only increase with age and lapsing centuries, whose eternal youth is beyond the reach of all decay. A century ago she was perhaps even more preeminent than now, for at that time geology and chemistry were mere infants, and the science of dynamical electricity had no existence. During the past hundred years she may, therefore, have lost something relatively by the rise and development of other branches, whose progress has outstripped her own. Yet her own progress has been wonderful. A hundred years ago no planet had ever been discovered: the heavenly bodies known to science were only the same (excepting the satellites of Jupiter and part of those of Saturn) which had been observed in Egypt and Chaldea in prehistoric antiquity. Observatories and observers were few and far between compared with their present numbers, and the instruments employed were far below those now used, in power and accuracy. Great things had indeed been accomplished by Galileo, Tycho and Kepler, by Newton and Halley and Bradley, Euler, Cassini and Clairaut, in the preceding two hundred years; but a new era of more intense activity was just opening. La Place and La Grange and Herschel had begun their work, and were to be followed by Gauss and Encke; Fraunhofer, Struve, Airy and the younger Herschel, by Adams and Leverrier and Pierce, Hansen and Delaunay and Newcomb and an uncounted multitude, who each have contributed something of importance to the fund of knowledge. Since 1776 two great worlds, eight satellites, one hundred and sixty-six minor planets, some forty periodic comets, and the hosts of meteors have been added to the rolls of the Solar System. A century ago about one hundred double stars were all that were known. Since then some ten thousand have been discovered, their physical connection has been demonstrated and investigated, and the periods and orbits of many have been worked out. The number of nebulæ and clusters has been increased from less than a hundred to more than seven thousand, and their nature and physical constitution ascertained. The parallax of fixed stars has been measured, their distance determined, and their motions, and that of the Solar System, through space have been brought to light and to some extent investigated. The sun and stars have been analyzed in their chemical constitution, and a host of new and most interesting results have been reached by instruments and methods undreamed of a hundred years ago. New and more precise methods of computation have supplanted the old. The accuracy of angular measurements, and the delicacy of graduation and reading, have been greatly increased. The elec tro-magnetic methods of recording time-observations have superseded the older fashions. Telescopes have been enormously improved-refractors almost beyond belief; for a hundred years. ago not a single one had ever been made with an aperture exceeding four inches; and even fifty years ago the Dorpat refractor of nine inches aperture, was regarded as hardly less than a miracle of art. Reflectors of considerable power had indeed been built, but the great instruments of Herschel and Ramage were not constructed until later. The polariscope and spectroscope, to which we owe so large a part of our limited knowledge in regard to the constitution of the heavenly bodies, have both been invented since 1800. Altogether we think it may safely be asserted that in no equal period of human history, has astronomy progressed so rapidly, or so widely extended her domain. To this great advance our own country has made her contributions, small perhaps, but real and creditable—not by any means so great as those of England, France, and Germany, nor so great perhaps as might fairly have been expected of a nation where education has been so widely diffused, and thought and action so free; but still enough to obtain for her a place and honorable mention in the history of science. The only astronomical work of any importance done in this country before the revolution, was the measurement of the so-called Pennsylvania arc of the meridian, by Mason and Dixon in 1764; and the observations of the Transit of Venus in 1769, by a committee of the American Philosophical Society. Rittenhouse was the chairman of the committee, and the observations seem to have been among the best made anywhere, as the weather was perfect, and the skill and care of the astronomers concerned fully competent to the work. During the first half century of our national existence, science of every kind was utterly neglected; astronomy especially seems to have been regarded almost with aversion by the popular mind, as something aristocratic and unrepublican. When Hassler in 1807 submitted to the Government the project for the Survey of the Coast, it contained a provision for the establishment of an observatory to supply the needed astronomical data; but the proposition received no favor. The original law authorizing the Survey omitted all mention of the subject, and the law of 1832 expressly prohibits |
