ADVERTISEMENT. The object of the GENERAL APPENDIX is to furnish summaries of scientific discovery in particular directions; occasional reports of the investigations made by collaborators of the institution; memoirs of a general character or on special topics, whether original and prepared expressly for the purpose, or selected from foreign journals and proceedings; and briefly to present (as fully as space will permit) such papers not published in the "Smithsonian Contributions" or in the "Miscellaneous Collections" which may be supposed to be of interest or value to the numerous correspondents of the Institution. 180 RECORD OF SCIENTIFIC PROGRESS. INTRODUCTION. While it has been a prominent object of the Board of Regents of the Smithsonian Institution from a very early date in its history to enrich the annual report required of them with scientific memoirs illustrating the more remarkable and important developments in physical and biological discovery as well as the general character of the operations of the Institution, this purpose has not hitherto been carried out on any very systematic plan. Believing, however, that an annual report or summary of the recent advances made in the leading departments of scientific inquiry would supply a want very generally felt, and would be favorably received by all those interested in the diffusion of knowledge, the Secretary has had prepared by competent collaborators a series of abstracts showing concisely the prominent features of recent scientific progress in astronomy, geology, physics, chemistry, mineralogy, botany, zoology, and anthropology. Other subjects which might properly have been included, such as those of terrestrial physics and meteorology, geography and hydrography, microscopy, &c., as well as the more practical topics of agricultural and horticultural economy, engineering, technology, and industrial statistics have, for the present, been omitted, both for want of time in which to have them properly digested and for want of space to allow them any sufficient presentation. With every effort to secure prompt attention to all the more important details of such a work, various unexpected delays frequently render it imprac ticable to obtain all the desired reports in each department within the time prescribed. In such cases it is designed, if possible, to bring up such deficiencies and supply them in subsequent reports. A similar digest, having the title of "Annual Record of Science and Industry," prepared under the general editorship of the present Secretary of the Institution, was commenced in 1871, and published in a duodecimo form by the Messrs. Harper, of New York.* This work was con *The "Annual Record of Science and Industry" was itself a successor to a similar year book entitled "The Annual of Scientific Discovery" commenced in the year 1850 under the editorship of Mr. David A. Wells, and published by Messrs. Gould and Lincoln, of Boston. The last-mentioned work was satisfactorily continued for sixteen years, from 1850 to 1865, inclusive, when it was suspended by the appointment of its editor, Mr. Wells, to the commissionership of internal revenue under the United States Treasury Department. The work was, however, resumed in 1867, under the editorship of tinued through eight annual volumes; but was discontinued with the volume for 1878. The present undertaking may, therefore, be considered as in some sense a continuation of the work published by the Messrs. Harper. It is scarcely necessary to remark that in a résumé of the annual progress of scientific discovery so condensed as the present, the wants of the specialist in any branch can be but imperfectly supplied; and very many items and details of great value to him must be entirely omitted. While the student in a special field of knowledge may occasionally receive hints that will be found of interest, he will naturally be led to consult for fuller information the original journals and special periodicals from which these brief notices or abstracts have been compiled. The contemplated plan of devoting some 250 pages of the annual report to such a compilation is not designed to preclude the introduction into the "General Appendix," as heretofore, of special monographs or discussions that may prove interesting to the scientific student. SPENCER F. BAIRD. Dr. Samuel Kneeland, who conducted it for the years 1867, 1868, and 1869. It then passed under the editorship of Prof. John Trowbridge, for the years 1870 and 1871, when it was finally discontinued, and the "Annual Record of Science and Industry" took its place. ASTRONOMY. BY PROF. EDWARD S. HOLDEN. INTRODUCTION. As the space available for the record of astronomical progress is comparatively small, the accounts here given must necessarily be the barest summaries, whose chief end is to call attention to work which has been done, in order that a reference may be made to more extended papers if desired. At the same time it is clearly impossible to give a specific reference to each of the papers consulted. For such bibliographic information the reader is once for all referred to DARBOUX et HOUËL'S Bulletin des Sciences Mathématiques et Astronomiques (monthly, Paris), to Nature (weekly, London), to Science (weekly, New York), to the Observatory (monthly, London), and to other standard journals. Free use has been made of reviews by writers in these and other periodicals, particularly of the Record of Astronomy, published by Dr. J. L. E. DREYER in the Scientific Proceedings of the Royal Dublin Society. NEBULE AND CLUSTERS. The Earl of ROSSE has published Parts 1 and 2 (0h to 14h R.A.) of the "Observations of Nebula and Clusters of Stars made with the sixfoot and three-foot reflectors at Birr Castle from the year 1848 up to about the year 1878" (Trans. R. Dublin Soc., Vol. II). This publication (of which the third part, comprising the last ten hours of R.A., is in the press) embodies all the work done on nebulæ since the erection of the six-foot telescope in 1845. In 1850 and 1861 abstracts of the observations on more interesting objects appeared in the Philosophical Transactions, but all these abstracts are given over again in the new publication, with the sole exception of the copperplate engravings, to which, however, in all cases references are made in the text. Though even now not every single note in the observing ledgers is published, nothing has been suppressed which can be of the slightest value or importance. The observations are given in the observer's own words, and the notes which were added by Mr. DREYER while arranging the work for publication are easily distinguished by being inclosed in brackets. These notes deal especially with questions of identification, and nearly all the new nebula which were found at Birr Castle in the course of years and which |