210 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. 



A few investigations were undertaken having directly in view 

 the meeting of postwar problems. Because of the importance of 

 Sitka spruce for aircraft production, a study was undertaken of its 

 grow^th, yield, and management. 



Because of the added importance, in view of renewed agitation 

 of the national need for the practice of forestry on private lands and 

 of a comprehensive program for securing the perpetuation of our 

 forest resources through combined public and private action, of ac- 

 curate data as to the growth and yield of the different types of 

 forest and the costs that may be involved in securing forest replace- 

 ment, many field measurements were restudied in the light of re- 

 cent experience and new data w^ere accumulated. Wliile the facts avail- 

 able are sufficient upon which to base a plan for inaugurating a 

 general policy, the actual carrying out of such a policy will demand 

 the prosecution of forest studies more comprehensive and far more 

 detailed than those hitherto undertaken if the plan is to be made to 

 work fully. 



Some of the fundamental prewar studies, such for instance as the 

 relation between distribution of the different forest types and the 

 climatic and soil factors that control them, the importance of farm 

 woodlands in the economic management of the farm, studies of the 

 physical, chemical, and biological properties of seed, studies of the 

 causes of forest fires and the liability of different forest types to 

 them, have been renewed and are to be pushed with vigor to com- 

 pletion. As a partial provision for meeting the need for fuller in- 

 formation relating to the proper handling of forests, a comprehensive 

 scheme for forest investigation in cooperation with States and forest 

 schools has been developed. 



MISCELLANEOUS. 



Thirty-seven new publications were issued. The distribution of 

 Forest Service publications totaled 316,000 copies. About 62 'ad- 

 dresses were made, mainly at expositions and upon recjuests from 

 National Forest users, lumbermen's associations and similar trade 

 bodies, technical societies, and educational institutions. Lantern 

 slides were loaned to more than 208 persons engaged in educational 

 work. These were shown 422 times and to 10,293 persons. Ad- 

 ditions to the photograph collection totaled 1,154 and to the lantern- 

 sHde collection 1,186; and 924 lantern sHdes, 29 transparencies, and 

 472 bromide enlargements w^ere colored. Traveling exhibits of pho- 

 tographs, maps, drawings, and wood samples were loaned to 128 

 schools and libraries. Through sales, loans, and gifts 4,890 indi- 

 vidual photographic prints were made available for outside illustra- 

 tive purposes. 



Additions to the Service library in Washington totaled 765 books 

 and pamphlets. The index of forest Kterature was extended by 

 entries covering 2,725 books, periodical articles, and manuscripts. 

 Loans from the library totaled 2,883 books and 5,841 periodicals. 

 The 162 branch field libraries now contain 31,602 books recorded 

 in the main library, besides various State and other publications not 

 so recorded. 



