THE LIBRARY. 679 



this division, the number of readers of each periodical varying from 1 to 14. 

 All articles believed to be necessary in future work are marked by the read- 

 ers and are afterwards indexed in the division libniry. Only 2S periodicals are 

 filed in this division, all others being returned to the main Library as soon as 

 indexed. 



INDEXING. 



The regular dairy index, so called, which is maintained in the Dairy Division, 

 aims to be a practical working index of material of actual use in the work of 

 the Dairy Division. Its entries include books, bulletins, articles in periodicals 

 and other listed information, as dates and places of the various meetings of 

 the International Dairy Federation, addresses of manufacturers of milk-con- 

 densing machinery, and other such information as is in constant demand and 

 may be appropriately grouped on a subject card. The index is occasionally 

 run through and cards no longer of actual use are discarded. 



There is in addition to this an index of material on bacteriology in its rela- 

 tion to the dairy industry. This index was the result of many years of private 

 endeavor of one man, and while in constant use in the dairy laboratories could 

 be withdrawn at any time by the resignation of its owner. About two years ago 

 this index was verified and revised by the Dairy Division library, the corrected 

 cards being returned to the owner and copies being filed in the Dairy Division 

 library. This index is now being kept up in duplicate, it being estimated by 

 the library that the work done for the individual is by no means commensurate 

 with the material obtained from him. 



An additional index on gas-producing bacteria, which might be considered 

 the amplification of one section of the catalogue mentioned above, is now being 

 revised in a similar manner and is being extended by further references wher- 

 ever found. An index to literature on enzymes is being compiled in the dairy 

 laboratories in direct connection with their work, and it is expected that this 

 uiateral will ultimately be verified by the library and put into the same form 

 as the other indexes in the division. It is hoped that in time all the library 

 copies of these indexes may be consolidated. 



Indexes to photographs, lantern slides, and bromide enlargements owned by 

 the Dairy Division are also maintained by the Library. The photographs are 

 indexed by number, for inventory and oflice purposes, by States and by sub- 

 jects. The last two are not exhaustive, but include only entries of the more 

 important photographs. 



Lantern slidee ai'e also indexed by number and by subject, the latter index 

 not being exhaustive. The bromides are indexed by number only. 



A further statement in regard to the photographic work will be found else- 

 where in this report. 



REFERENCE WORK. 



The demands on the Library for reference work vary greatly during the 

 year, according to the character of the work being done by the division. It 

 includes the collection of material for addresses, reports, letters, publications, 

 etc. Frequently this material can be easily located or listed from the card 

 catalogue, but new questions are continually coming up and further research 

 is necessary. Other indexes in the department are used whenever possible and 

 much time is saved in this way. For instance, when the subject of sewerage, 

 drainage, and septic tanks was taken up by this division in connection with 

 creamery and farm buildings, it w;is found that the library of the Bureau of 

 Plant Industry has many of the most useful periodical articles already indexed 

 in connection with the work of that bureau on water pollution. There are 

 kept on hand for use in correspondence small supplies of carbon copies of brief 

 bibliographies on subjects of pressing current interest, such as results of State 

 work on milking machines, proposed legislation on oleomargarine, lists of 

 dealers in creamery supplies, etc. 



PUBLICATIONS. 



All bibliographies for Dairy Division publications are sent to the division 

 library for verification and to be put into the accepted bureau form. Occa- 

 sionally authors leave the compilation of the brief bibliographies appended to 

 their bulletins to the librarian, when most of the published material which 

 they have used has been selected through the division library catalogue. In 

 such cases the bibliographies are submitted to the authors for final review. 



