ing steamers report the fact by wireless telegraph to the Navy wireless station at Tatoosh Island, and, in case of fog, to use this means to report their passage to and from the strait.

The service rendered by the seacoast telegraph and vessel-reporting stations of the bureau has been of great benefit to shipping in times of disaster during the last year. At about 11 p. m., September 1, 1910, the steamer Watson, bound from Puget Sound to San Francisco, with passengers and general cargo, ran ashore at Waddah Island, Wash. It was floated at 1 a. m., September 3, by the aid of the lifesaving tug Snohomish, which was wired for at Port Angeles by our observer at Port Crescent immediately after the wreck. On December 10, 1910, following the wreck of the schooner William H. Davidson, our repairman at Manteo, N. C., established a temporary telegraph station on the coast about 30 miles north of Manteo, at the scene of the disaster, and rendered great assistance to the master and crew. Twelve wrecks occurred between Cape Henry and Hatteras during the year, all of which were reported by the life-saving stations to the officials at the Weather Bureau telegraph offices at Cape Henry, Hatteras, and Manteo, who in turn promptly telegraphed the information to the various agents, owners, revenue cutters, wrecking companies, and maritime exchanges. It is estimated that fully $328,250 was saved through the assistance rendered the vessels in distress as a result of these timely reports. Reports of 18 casualties on Lake Huron, in which property valued at $350,000 was endangered, were also given out from the Alpena, Mich., station, as a result of information received by our observer at that point over the Weather Bureau land and cable lines running between the mainland and Middle Island and Thunder Bay Island.

CLIMATOLOGICAL DIVISION.

The Annual Report of the Chief of the Weather Bureau, 1909-10, was printed and ready for distribution early in the present calendar year. The transfer of the composition and printing of the Monthly Weather Review from the central office of the Weather Bureau to the Government Printing Office has occasioned some delay in the issue of that publication, but it is probable that arrangements can be made whereby its issue at a slightly earlier date may be possible.

The issue of the National Weather Bulletin, weekly during the crop-growing season and monthly thereafter, continued as in the past. Its increased circulation as a result of numerous requests indicate that its value is rapidly becoming more widely known and appreciated.

The weekly and monthly summaries of the weather conditions in Porto Rico and Hawaii were issued as in the past, as well as those for Iowa, in cooperation with the weather service of that State.

Weekly summaries of the snow and ice conditions, with special reference to the districts east of the Rocky Mountains, were issued as usual during the winter, as well as the monthly summaries of snowfall conditions, for the benefit of irrigation and other interests in the mountain portions of the West. The latter contain more data than formerly, and the information they present as to the amount and distribution of the snow in the mountains, and its condition as regards prospects for early or late melting, has proved of much value

to engineers and those dealing with the storage of water for power purposes and its distribution for irrigation.

The daily bulletins of weather conditions over the great corn, wheat, cotton, sugar, and rice growing States have been issued regularly from about 40 selected points in those districts, the total issue amounting to more than 2,000 copies daily. The demands for the extension of these services have been numerous and persistent, especially for the establishment of additional telegraphic reporting stations in the cotton-growing sections of Texas and Oklahoma and the wheat-growing districts of Montana and the Dakotas. These demands have been partially met by the establishment of about 20 additional telegraphic reporting stations, mostly in the western portion of Texas and in the Dakotas. The necessity of more stations of this character is still being urged by the many beneficiaries of these services.

The published annual summaries of climatological data for 1910, for the several States, have served as valuable additions to the series, which has been continued since 1896.

The preparation and printing of the 106 Summaries of Climatological Data, covering the entire United States, have been completed. These summaries have proved almost invaluable in answering the thousands of requests for information regarding the climatic features of the different portions of the country, and the public demand has been so great that reprints of several of the earlier issues have already become necessary.

During the year there was prepared and issued as "Bulletin V, Frost Data of the United States," a set of charts showing the average dates of first killing frost in autumn, average dates of last killing frost in spring, earliest dates of killing frost in autumn, latest dates of killing frost in spring, and the length, in days, of the crop-growing season for all portions of the United States. These charts were prepared from the records of about 1,000 cooperative observing stations having the greatest length of record. As the observations selected were made largely in the open country and therefore removed from the artificial conditions that prevail in the cities, where most of our regular stations are located, they show the conditions that are liable to prevail in the fields, orchards, and gardens more accurately than ever before attempted.

The Weather Bureau derives much of its important climatological data from the records of its cooperative observers, of whom there are at present about 4,000, reporting from points well distributed throughout the entire United States, including Alaska, Porto Rico, and the Hawaiian Islands. Changes in this feature of the work included the opening of 258 new cooperative stations, and the discontinuance of 150 formerly in operation.

The great extension of the agricultural interests, especially those of trucking and fruit raising, necessitates more exact knowledge regarding the details of the climate of the country as an aid in determining the crops and fruits best suited to the various portions. At the present time this need can only be met by the data furnished by the cooperative observers of the bureau.

The demands for the extension of these reporting stations have been much greater than it was possible to meet. As a rule, new stations have been established only in the more recently settled dis

tricts of the western portion of the country, where the necessity for reliable climatological data is most urgent.

The routine work of the division, comprising the furnishing of climatic data to several thousand applicants, the preparation of certified data showing weather conditions for use in courts, and the tabulation of data into the permanent record books, has been carried forward as usual.

During the year a large number of the original records, including all the river reports, and the summaries of climatological data from 1906 to 1910, inclusive, have been collected, arranged, and properly bound. In September, 1910, the work of examining the original meteorological records from stations was transferred to this division, due to the discontinuance of the distributing division.

The large accumulation of original records is rapidly exhausting the available storage room in the vault, which will soon have to be enlarged if these valuable records are to be kept free from danger of destruction by fire.

INSTRUMENT DIVISION.

The work and duties of the Instrument Division have remained essentially the same during the past year as heretofore. The equipment of instruments at about 200 telegraphic stations and about 4,000 cooperative stations has been maintained in the best condition possible.

Improvements have been made in the equipment of the stormwarning display stations at Delaware Breakwater, Del., Cape Henry, Va., and Sand Key, Fla., through the substitution of acetylene gas for oil in the lanterns, and more particularly through the introduction of separate lanterns, operated by a special signaling key for use in flashing messages from the stations to passing vessels. Credit is due to Mr. J. F. Newsom, in charge of the station at Cape Henry, for the development of this and other useful apparatus for signaling passing vessels.

Kiosks were installed during the year at Indianapolis, Ind., Salt Lake City, Utah, and Memphis, Tenn. These structures, which are now to be found at 29 stations, have met with universal commendations from commercial bodies and the general public, and requests for others are on file, awaiting consideration at such time as funds may become available for their erection. The kiosk has proved of special value in placing meteorological and climatological data of general interest before the public, as well as in affording a display of the instruments used for indicating and recording temperature, humidity, rainfall, and atmospheric pressure. During the year an improved arrangement of counters was devised by Mr. Maring, of the Instrument Division, for showing the accumulated rainfall since January 1, side by side with the normal fall for the same period, so that the data could be compared at a glance and the excess or deficiency for the current year noted.

Special forms of apparatus promising to give satisfactory results in the accurate measurement of snowfall in the mountain regions are described and illustrated in an Instrument Division circular issued during the year under the title "Measurement of Precipitation. limited number of sample gauges were installed late in the season at a

few selected stations, but the records obtained are not as yet sufficiently numerous to bring out any definite results.

Work upon the apparatus for the absolute measurement of solar radiation has been carried forward, and a number of comparisons have been made with different types of receivers, bridges, etc. Orders were placed in the latter part of the year for an improved form of recording Wheatstone's bridge for the continuous registration of sunshine.

The seismographs at Washington have been maintained in operation throughout the year, but no work of a seismological character has been done at any of the other stations, notwithstanding the general call from a number of sources that the Weather Bureau engage in this important work. It is hoped ample means and authority will be granted the Weather Bureau to add seismological work to its present duties.

LIBRARY.

During the year just ended, 1,064 books and separate pamphlets were added to the library, which now numbers approximately 31,000 volumes. All additions were fully catalogued under author and subject.

As heretofore, all the scientific periodicals received in the library, including annuals, were regularly searched for articles of meteorological interest. These periodicals include all the important journals of general science, and most journals devoted to physics, geophysics, geography, and other subjects germane to meteorology, in many languages. The proceedings and transactions of learned societies are well represented. All articles of permanent meteorological interest were catalogued under author and subject; and in many cases brief notes were added on the catalogue cards to amplify the information conveyed by the titles.

The periodical literature is, as a rule, more highly specialized than that published in book form, and is therefore indispensable to the special student. The work of cataloguing such literature under appropriate topical headings, about a thousand of which are now used in the library, requires on the part of the cataloguers a wide knowledge of meteorology and of the principal foreign languages, besides familiarity with library science in general. Hence the Weather Bureau needs to maintain a strong library staff, specially trained in handling the cosmopolitan literature of meteorology, and in sympathetic relations with the scientific staff of the bureau, to whom it is essential that this literature shall be made readily accessible.

Only by virtue of its direct exchange relations with scientific institutions throughout the world is the bureau able to secure promptly all the current publications on meteorology. Much of this literature, especially that of an official character, could not be obtained by purchase, even if the funds were available. The periodical publications of the bureau, especially the Monthly Weather Review and the Bulletin of the Mount Weather Observatory, are an indispensable means of securing valuable literature through exchange.

Select lists of new meteorological publications have been published regularly in the Monthly Weather Review, as in former years. A revised edition of the librarian's "Brief List of Meteorological Textbooks and Reference Books" was issued during the year.

The library continues to make all translations from foreign languages required in the bureau; to supervise the small libraries maintained at about 200 stations; and to perform the work at the central office in connection with promotion examinations. All these classes of work have grown steadily during the past year.

Several station libraries have been strengthened by the addition of important works in German and French, dealing with branches of meteorology that are not adequately treated in English. This applies especially to the literature of atmospheric electricity, atmospheric optics, and climatography.

In recording the growth of the library it appears proper to mention specifically a few of the more important meteorological works published in the course of the year, copies of which have been received.

Doubtless the greatest interest in this connection attaches to the completion of J. Hann's Handbuch der Klimatologie, third edition, of which the third and final volume has recently appeared. This work, in its successive editions, is the only extensive treatise on the climates of the world published during the past 20 years.

W. Trabert's Lehrbuch der Kosmischen Physik (Leipzig, 1911) is the most noteworthy recent publication belonging to the class of general textbooks of meteorology. A long-awaited new edition of the International Cloud Atlas has appeared. It introduces few changes in the existing classification of clouds, officially adopted in all countries.

Aerology and aeronautical meteorology engage the attention of a rapidly increasing number of writers. Dr. Franz Linke's Aeronautische Meteorologie, the first volume of which was recently published, is the prototype of a class of books likely to become common. It is a practical handbook dealing with the branches of meteorology of special interest to aeronauts. A third edition of Moedebeck's Taschenbuch für Flugtechniker und Luftschiffer is, like the earlier editions, strong in the meteorological branches of the subject. Messrs. A. L. Rotch and A. H. Palmer have issued a novel series of Charts of the Atmosphere for Aeronauts and Aviators. The British Government has published a noteworthy Report of the Advisory Committee for Aeronautics, 1909-1910, containing several papers by the director of the meteorological office.

The Carnegie Institution has published the first volume of a work on Dynamic Meteorology and Hydrography, by Prof. V. Bjerknes and others. Its object is to present the fundamental facts and principles of the subject in a form suitable for treatment by the mathematical physicist, in part according to methods not heretofore applied.

Dr. B. Walter has described an ingenious method of photographing lightning flashes with two cameras, one moving and the other stationary. (Über Doppelaufnahmen von Blitzen, Hamburg, 1910.) Dr. Suring has contributed an important treatise on meteorological photography to K. W. Wolf-Czapek's Angewandte Photographie in Wissenschaft und Technik, volume 1 (Berlin, 1911).

Important works on the circulation of the atmosphere included The Trade Winds of the Atlantic Ocean, published by the British Meteorological Office; W. J. S. Lockyer's Southern Hemisphere Surface-air Circulation, published by the British Solar Physics Committee; and a fourth installment of H. H. Hildebrandsson's Quelques