204 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. 



The States of Alabama, Florida, Georgia, Idaho, Illinois, Maine, 

 Massachusetts, Montana, New Hampshire, North Carolina, Tennessee, 

 and Texas received assistance during the year in formulating forest 

 policies, drafting forestry laws, and the like. 



RESEARCH. 



INVESTIGATIONS IN FOREST PRODUCTS. 



From many standpoints the fiscal year 1919 was the most important 

 in the history of the Forest Products Laboratory. Not only were 

 many of the research projects started earlier in the war brought to a 

 productive conclusion, but the peace-time application of their results 

 was aggressively undertaken through widespread dissemination of the 

 information and through personal contact with the wood-using 

 industries. 



During the first months of the year the laboratory was engaged 

 exclusively on special war problems. Cooperation with the various 

 bureaus oi the War and Navy Departments which had provided spe- 

 cial allotments was at its height, and requests from these departments 

 had become increasingly specific. After the armistice was signed it 

 was necessary to reduce the staff from 458 to approximately 300 per- 

 sons and to discontinue some of the less important investigations. In 

 accord with the desires of the War and Navy Departments, however, 

 the more important projects which were nearing completion, or which 

 were of special value, were continued. A number of new research 

 projects were begun, but the year's accomplishments were, primarily, 

 the outgrowth of fundamental research begun earlier in the war or 

 prior to the beginning of the war. 



Aircraft problems continued to occupy the position of greatest im- 

 portance. The large fund of available data on wood, plywood, and 

 glues found direct application in the solution of specific problems 

 arising from time to time in the design of aircraft. Many requests 

 were received from the War and Navy Departments for the develop- 

 ment of various aircraft parts which could not well be designed with- 

 out actual tests. Much of this work developed as a result of the suc- 

 cessful design by the laboratory of a plywood wing rib for one of the 

 Army planes. 



Ribs for almost a dozen different types of Army and Navy planes 

 were designed and tested by the laboratory and gradually improved 

 to the point of maximum strength and minimum weight. These ribs 

 were, in all cases, decidedly superior to commercial ribs, of correspond- 

 ing sizes. In addition to the specific design of these ribs, general 

 laws governing the types of ribs to use for different siz^es were devel- 

 oped, and several excellent types of large ribs perfected. 



The design of airplane wing beams presented many complicated 

 problems, and the laboratory was called upon to conduct elaborate 

 series of tests on full-sized members to determine the relative merits 

 of the many different types. The growing scarcity of suitable air- 

 craft woods, demanding closer utilization of existing supplies, made 

 it necessary to develop types of built-up beams which would permit 

 the use of small and short stock. Tests were made upon several 

 hundred beams of a number of different types, and several types were 

 developed to meet the specific requirements involved. 



Exhaustive tests were also made upon many different types of 

 beam splices, and their relative efTiciency was determined. As an 



