228 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. 



the conservation of soil on hillsides; and the proper depth, spacing, 

 and arrangement of open ditches and tile drains for the various 

 kinds of soils. In the irrigated region special study is made of the 

 movement of gi'ound water and of the effectiveness of drainage in 

 removing alkali. While definite quantitative results in some of these 

 lines must wait upon further investigations, the data already ob- 

 tained have enabled invaluable advice to be given with respect to 

 particular projects. 



LIBRARY. 

 LARGEST COLLECTION OF AGRICULTURAL LITERATURE. 



The growth of the library during the past 16 years has more than 

 equaled its growth during the previous 34 years of its existence. In 

 1897 it contained ajDproximately 59,000 books and pamphlets, while 

 to-day its collections number 122,000 books and pamphlets. The 

 library at the present time contains the largest collection of litera- 

 ture in this country on agriculture and related sciences, and as far as 

 known is the largest agricultural library in any country. 



In the subject of American agriculture, including horticulture, 

 forestr}^, pomolog}^, dairying, live stock, poultry, agricultural sta- 

 tistics, and the various agricultural crops, it is especially complete. 

 In addition, it has a large and representative collection of the most 

 important foreign agricultural books and periodicals and a collec- 

 tion of the publications of foreign agricultural institutions, societies, 

 and experiment stations, which is without question the largest and 

 most complete in the United States. In the sciences that relate to 

 agriculture, such as botany, chemistry, and zoology, the library's 

 resources compare favorably with the resources of the large college 

 and reference libraries of the country in these subjects, and along 

 economic lines are probably unsurpassed. 



It is especially strong in scientific and technical periodicals and 

 society publications. Nearly 2,000 periodicals are being received 

 currently, of which number a little less than two-thirds are sent as 

 gifts and exchanges. 



CATALOGUES. 



Since 1897 the appropriation for the library has been increased 

 from $13,960 to $40,500, and the staff has grown from 6 to 29. There 

 has been a corresponding increase in the activities and usefulness of 

 the library. Only a comparatively small portion of the library was 

 catalogued in 1897 ; to-day the dictionary card catalogue, containing 

 approximately 286,000 cards, includes entries for nearly all the 

 books in the library and is an invaluable key to the literature of 

 agriculture and the related sciences. In 1899 the issuance of a card 

 catalogue of the publications of the department was begun by the 



