the nucleus, as published in "Experiments with Ionized Air" (Smithsonian Contributions to Knowledge, vol. XXIX, 1901) and ir "Structure of the Nucleus," issued as part of the same volume in 1903. The investigation was carried on with the aid of a grant from the Hodgkins fund. Doctor Barus describes the nucleus as a dust particle small enough to float in the air but larger than the order of molecular size, and shows that such a particle precipitates condensation in an atmosphere saturated with water in its immediate vicinity. He uses the term "nucleation" to denote the number of nuclei per cubic centimeter regardless of their source-which may be from mechanical, thermal, chemical, high potential, or radio-active processes-or their special properties. By far the greater number are initially ionized, or at least carry an electric charge, and where they occur in thousands and millions of approximately uniform size they give rise to condensational phenomena of transcendent beauty and importance.

The articles printed in the Miscellaneous Collections are, as the name of the series would indicate, miscellaneous in character. The past year has added 38 numbers to this series of papers, including several relating to the bibliography of chemistry; an exhaustive catalogue of Diptera, or two-winged flies, showing the geographical distribution of several species known to spread disease; accounts of explorations in Alaska and among the Canadian glaciers; some interesting popular papers by Doctor Gill on the sculpin, the tarpon, the ladyfish, and the carp, and a lecture by Dr. Andrew D. White on the diplomatic service of the United States, the first of the series of lectures under the Hamilton bequest.

The Contributions and Miscellaneous Collections just spoken of are published at the expense of the Institution fund in editions of 1,500 copies, and are intended solely for distribution to the large libraries and institutions of learning throughout the world.

The Annual Report, on the other hand, is published by a Government appropriation in an edition of some 12.000, and is intended for a more general distribution. Primarily, this volume is a report to Congress on the operations of the Institution during the year, but its popular interest lies largely in its General Appendix, containing a number of papers showing the recent progress of the world's scientific work. To the selection of appropriate papers for this Appendix I have given much personal attention for several years past.

The manuscript of the work of the late Dr. G. Brown Goode, on some contributions of America to the progress of science, which during the past year has been worked over by Mr. Kenneth M. Goode, editorial assistant, is now almost in its final shape, and will, I hope, appear as a Smithsonian publication during the coming year.

The Institution proper distributed during the year a total of 60,063 volumes or parts of volumes of the series of Smithsonian Contributions, Miscellaneous Collections, Reports, and publications not included in the regular series, making an increase of 13,455 over the number sent out during the previous year.

THE LIBRARY.

The library of the Smithsonian Institution is, first of all, a library of science, and, secondly, a collection of catalogues and bibliographical apparatus. The general aim, as stated in the original plan, has been "to procure a complete collection of the memoirs and transactions of learned societies throughout the world, and an entire set of the most important scientific and literary periodicals." In 1866 the main portion of the Smithsonian library was for administrative purposes transferred to the custody of the Library of Congress, and became one of the important elements of that great National Library. This collection continues as the Smithsonian Deposit. It has annually increased in size and importance, and at present aggregates nearly half a million entries.

There is retained at the Institution such books as are of immediate importance to investigators carrying on their researches in the Smithsonian building. This reference collection, together with the special libraries of the National Museum, the Astrophysical Observatory, the National Zoological Park, and the Bureau of American Ethnology, numbers about 55,000 volumes.

Besides the accessions of books from customary sources, during the past year there has been received a valuable library relating to civil engineering bequeathed to the Institution by the late Dr. J. Elfreth Watkins; also a collection of about 1.600 books on the flora of tropical America, presented by Capt. John Donnell Smith, and a large number of additions to the Watts de Peyster Collection Napoleon Bounaparte.

The International Catalogue of Scientific Literature established three years ago, with administrative headquarters in London, now contains over half a million reference cards, 50,000 of which are references made for the United States by the Smithsonian Institution. The entire work of preparing cards for this country is done in connection with the library of the Institution, the cost of the work thus far having been borne out of an allotment made by the Institution.

a Contributions to Knowledge, 4,540; Miscellaneous Collections, 27,558; Reports, 25,425; publications not in regular series, 1,905; publications not Smithsonian yet distributed by the Institution, 635.

CORRESPONDENCE.

From its correspondence it appears that the Institution is generally considered by the public as an establishment to which requests may be addressed for information on all branches of knowledge, for the solution of various scientific problems, for the examination and indorsement both of scientific investigations and crude, unscientific speculations, for supplying answers to questions in prize contests, and the like. It seems well, therefore, to state that while responses are cheerfully given, as far as practicable, to all legitimate requests for scientific information, the Institution does not undertake to maintain a general question bureau. The communications received cover every conceivable subject, from new theories of the physical phenomena of the universe to a request for information as to the value of some supposedly rare book, and the preparation of the data desired entails the expenditure of a considerable amount of time and labor by the members of the Institution's staff. Many of these correspondents are men of considerable culture and of much general reading, but are wanting in that special training which is necessary for successful scientific investigation, and correspondence with this class is especially difficult to manage, since the rejection of the propositions made is generally attributed to prejudice and is resented by the writers, who array themselves as martyrs to science.

During the year many letters have been received from inventors who desire either grants of money with which to develop their various devices or an expression of the Institution's opinion as to the merits of their inventions. As the Institution has no funds from which such aid can be given, and as the Secretary is prohibited by a decision of the Board of Regents from expressing an opinion of this character, he is obliged to refuse all such requests. It would seem proper to state also that the Institution does not supply information of a commercial nature, such as is customarily furnished for a fee by engineers or other professional advisers, or which is designed to benefit some individual rather than the public.

In spite of these restrictions, however, the conduct of this correspondence is an important agency for the diffusion of knowledge

among men.

NATIONAL GALLERY OF ART.

In the message of President Roosevelt communicated to the two Houses of Congress at the beginning of the third session of the Fifty-eighth Congress (dated December 6, 1904) he says:

The collection of art contemplated in section 5586 of the Revised Statutes should be designated and established as a national gallery of art, and the Smithsonian Institution should be authorized to accept any additions to said collection that may be received by gift, bequest, or devise.

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*

The section of the Revised Statutes cited by the President is the act of foundation of the Smithsonian Institution, which declares that "whenever suitable arrangements can be made from time to time for their reception, all objects of art and of foreign and curious research, all objects of natural history, plants, and geological and mineralogical specimens belonging to the United States * shall be delivered to such persons as may be authorized by the Board of Regents to receive them, and shall be so arranged and classified in the building erected for the Institution as best to facilitate the examination and study of them;" so that the first object of the Institution, in the eyes of its founders, appears to have been to give it the curatorship of the Art collections of the nation.

During its early years this object was promoted in various ways; among others, by the acquisition of a very valuable collection of prints and engravings belonging to the Hon. George P. Marsh. After the fire in the Institution in 1865 these prints were deposited for temporary safe-keeping in the Library of Congress and (with other works of art) in the Corcoran Gallery.

Subsequently an appropriation was granted by Congress for making a fireproof room in which these could be kept, but it was not until 1896 that the Regents provided for their recall to the Institution. In the journal of the proceedings of the Board for 1896 (Smithsonian Report, 1896, pp. xiii and xiv) will be found the action taken by the Board providing for their restoration to their own immediate control. The following resolution offered then by Senator Gray was adopted: Resolved, That the question of the propriety of bringing the works of art belonging to the Institution under the more immediate control of the Board of Regents be referred to the executive committee and the Secretary, with power to act.

In pursuance of this the Institution brought back to its own keeping a number of prints of value, both from the Library of Congress and the Corcoran Gallery, leaving, by an amicable understanding with the latter establishment, as a loan, a few of the works of art, notably a large picture by Healy.

The old name of the collections was the "Gallery of Art," a title which seems almost too ambitious for the present collections of the Institution, though it is to be hoped that this designation will be justified by their future increase. These have been placed by me in a room specially fitted up for that purpose (the Art Room), under the temporary charge of the librarian.

There is now in the courts awaiting legal interpretation a will containing a bequest of a valuable collection of art objects.

On January 3, 1905, Mr. Charles L. Freer, of Detroit, offered under certain contingencies to bequeath to the Smithsonian Institution his valuable art collection, proposing at the same time to provide after

his death for a building of appropriate design and proportion, provided the Institution would undertake its maintenance. The objects include a remarkable collection of the works of the late J. A. McNeil Whistler and a number of oriental art objects. The proposal of Mr. Freer is still under consideration by the Board of Regents.

HAMILTON LECTURE.

A number of years ago Mr. James Hamilton left a small bequest to the Smithsonian Institution, the income of which was to be appropriated biennially by the Secretary, either in money or a medal, for such contribution, paper, or lecture on any scientific or useful subject as the Secretary might approve.

The Regents of the Institution decided to let this small sum accumulate, and it is only recently that the Secretary has found himself able to commence to employ the income as a lecture fund. The first address under the auspices of this fund was delivered by Dr. Andrew D. White, LL. D., D. C. L., in the lecture hall of the National Museum on March 9, 1905, and was entitled "The Diplomatic Service of the United States with some Hints toward its Reform."

This lecture was printed by the Smithsonian Institution as a pamphlet of some twenty pages and was distributed to members of Congress, officers of the Department of State, various members of the diplomatic corps, the libraries of the larger universities, presidents of colleges, and others likely to be interested in the important question discussed.

SMITHSONIAN DELEGATES AT INTERNATIONAL CONGRESSES.

Congress on Zoology.-Messrs. Leonhard Stejneger and Gerrit S. Miller, jr., of the United States National Museum, represented the Institution and Museum at the Sixth International Congress on Zoology held at Berne, Switzerland, August 14-19, 1904.

Congress of Americanists.-Mr. William H. Holmes, Chief of the Bureau of American Ethnology, represented the Institution at the Fourteenth International Congress of Americanists held at Stuttgart, August 18-23, 1904. He delivered an address on the "Contributions of American Archeology to Human History" and presented to the congress a set of 75 bound volumes relating mainly to American archeology and ethnology, published by the Smithsonian Institution and its two Bureaus-the National Museum and the Bureau of American Ethnology.

Congress of Orientalists.-Prof. Paul Haupt, honorary curator of the Division of Historical Archeology, United States National Museum, represented the Smithsonian Institution and the Museum at the Fourteenth International Congress of Orientalists held at Algiers in April, 1905,