182 ANNUAL REPORTS OF DEPARTMENT OF AGRTCULTURE. 



few selected stations, but the records obtained are not as yet suf- 

 ficiently numerous to bring out any definite results. 



Work upon the apparatus for the absolute measurement of solar 

 raiiiation has been carried forward, and a number of comparisons 

 have been made witli 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 

 througiiout 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 tiiat 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. Ail 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 meteor- 

 ological 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 amphfy the information 

 conveyed by the titles. 



The periodical Hterature is, as a rule, more highly specialized than 

 that pubhshed 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 '^leteorology and of the principal foreign languages, 

 besides familiarity with librar}^ science in general. Hence the 

 Weather Bureau needs to maintain a strong library straff, specially 

 trained in handling the cosmopohtan 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 insti- 

 tutions 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 publica- 

 tions 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 fists 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 Text- 

 books and Reference Books" was issued during the year. 



