THE LIBRARY. 



665 



libraries of the various bureaus and offices in which they are of 

 special interest. The remaining three-fourths are filed in the main 

 Library, but of this number only about one-half, namely, TOO, can be 

 kept in the pigeonholes in the periodical reading room on account of 

 the limited space available. 



It is impracticable to keep a complete record for the whole year 

 of the receipt and circulation of current periodicals, but, as in pre- 

 vious years, a count was made of the current periodicals handled 

 daily for a limited period, namely, from April 4 to June 1 in the 

 present year, which, compared with a similar count for May, 1009, 

 and May, 1910, is as follows: 



Current periodicals. 



New numbers received and recorded 

 Daily average 



Returns from circulation 



Daily average 



May, 1909 

 (25 days). 



4,523 

 181 



4,731 

 189 



May 7 to 



June 6, 1910 



(25 day.s). 



4,923 

 197 



5,T04 

 204 



Apr. 4 to 



Junel, 1911 



(49 days). 



9,450' 

 19a 



14,02S 

 286 



From the above statement it will be seen that the daily average of 

 new numbers received and recorded is a little less in 1911 than it 

 was in 1910, whereas the daily average of returns from circulation 

 shows an increase of 40 per cent, indicating a largely increased use 

 of the current periodicals. As explained in previous reports, these 

 figures do not, however, give any adequate idea of the use of the cur- 

 rent periodicals, as they represent little more than the circulation to 

 bureaus and offices. Of the 1,978 periodicals currently received, be- 

 tween 1,200 and 1,300 circulate regularly among the various bureaus, 

 divisions, and offices; the number to which each periodical is regu- 

 larly sent varying from 1 to 20. The circulation in a bureau is at- 

 tended to by the library of the bureau, some periodicals being sent 

 regularly to 24 individuals. After circulating in this way the num- 

 bers are returned to the main Library and sent out again to another 

 bureau or office for circulation in the same manner. To get an idea, 

 therefore, of the total circulation of current periodicals in the depart- 

 ment, the above figures of the main Library must be supplemented by 

 the data in regard to the circulation of periodicals given in the sepa- 

 rate reports of the bureau, division, and office libraries. 



As far as is known, this is the only library which attempts to cir- 

 culate its current periodicals regularly. That this service has grown 

 to its present pro]:)ortions is due largely to the following reasons: 

 (1) The various offices of the department are widely separated," (2) 

 the scientists of the department find it difficult to come to the Library 

 regularly during office hours to consult the periodicals; (o) the 

 Library has never had space for a periodical reading room hirge 

 enough to accommodate the current files of all the periodicals re- 

 ceived; (4) the work of the various bureaus is so broad that a very 

 large proportion of the periodicals received is of interest to several 

 bureaus, making it difficult. to divide the periodicals for filing in the 

 various bureaus and offices to which they are of interest without a 

 great deal of duplication; (5) the importance of the current period- 

 icals in the scientific work of the department. As a result of the 



