temperature in the United States from the earliest times to the present: these have been discussed by Prof. Schott, aided by computers paid from the Smithson fund. Still another work of this series is in progress on the "Geographical Distribution of Thunder-Storms," and another work will soon be commenced on the deductions from barometrical observations in the United States.
The Institution is also aiding in a research on the orbit of the periodic comet of Tuttle (time of revolution thirteen years), prosecuted under the direction of Prof. Stone. An investigation into the efficiency of steam-heaters has been aided by the Institution during the year.
"The diffusion of knowledge among men" is powerfully aided by the Smithsonian system of exchanges. The Institution is in correspondence with more than two thousand institutions, whose publications, etc., it distributes in this country, and to whom it forwards works relating to scientific and literary advances in America. As is said by the secretary in his report, "the effect of this system on the diffusion of knowledge cannot be too highly estimated." The exchanges in books and pamphlets alone amount to 5,546 in 1874, and these are deposited in the Library of Congress, where they are available for research. The telegraphic announcements of astronomical discoveries in Europe and America have been in operation since 1873, and are of the highest benefit to astronomical science. Six asteroids and six comets were so announced in 1874.
The National Museum is deposited in the building of the Institution, and is under the care of Prof. Baird, Assistant Secretary. Constant additions are yearly made to it from all parts of the world, and all sources are laid under contribution. Mr. P. T. Barnum gives to the institution all animals which die in his menagerie, and Mr. Blackford, of Fulton Market, New York City, selects, from the thousands of fish which come weekly into his hands, all rare and curious ones, which are at once sent in Ice to the museum. There is, indeed, no part of the globe from which contributions are not received. All the War Department and other surveys in the West, the Navy Department surveys and exploring expeditions, the State Department Boundary Survey, and many other collectors, deposit the results of their work here, where they are discussed and elaborated. The museum furnishes also, from its duplicates, specimens for study to specialists who desire them. Its collections of insects, etc., are deposited with the Department of Agriculture, and exchanges are constantly kept up with this and other institutions. The United States Fish Commission may be almost considered as a part of the Institution; the valuable results which have already accrued from its scientific and energetic labors are too well known to need more than a mention.
The secretary of the Institution has for twenty years been a member of the Lighthouse Board, and is now its chairman, and to this connection Science owes the extensive series of experiments on sound in its relation to fog-signals, which are published in the appendix to the light-house report for 1874. The results from these experiments will undoubtedly be a guide for all governments in their choice of a method of fog-signaling.
Besides the valuable report of the secretary, of which the above is an abstract, there are given: Eulogies on Laplace, Quetelet, and De la Rive, by Arago, Mailly, and Dumas; a lecture on Tides and Tidal Action in Harbors, by Prof. Hilgard; Observations of Atmospheric Electricity and Aurora, by Lemstrom; an essay on a Dominant Language for Science, by De Candolle; Underground Temperature, by Schott and Everett; The North Carolina Earthquakes, by Du Pre and Henry; Warming and Ventilation, by Morin; and several short communications on Ethnology. All of these translations and memoirs are interesting and valuable, and many of them deserve a special review, but we must be content to notice how carefully they are selected to aid in the diffusion of information not generally accessible.
Enough has been given to show that the closing words of the secretary's report are but a mere statement of present facts: "The Institution is successfully prosecuting the plan adopted for realizing the benevolent intention of its founder, in the way of increasing and diffusing knowledge
