WORK OF THE FOREST SERVICE 311 



the character of the flow of each stream. There has been no general 

 agreement among writers as to the exact influence of forests on cli- 

 mate and streamflow, and it is to be hoped that these investiga- 

 tions will furnish the basis for the settlement of some long mooted 

 questions." 



OTHER SILVICULTURAL INVESTIGATIONS 



Among other silvicultural studies of the Forest Service are those 

 relating to forest mensuration, that is, studies as to the growth, 

 volume, and yield of the different species and types of forests ; pro- 

 tection studies, aiming to ascertain the exact eff'ect of fire, grazing, 

 diseases, insects, animals, snow, hail, and wind; regional studies, to 

 secure authentic information concerning the forest resources of state 

 or forest regions ; silvical studies, which try to establish a definite 

 relation between the forest region, forest types, and forest trees in 

 general, and the climatic and physical factors affecting their distribu- 

 tion and growth; and also some field studies in utilization of timber. 



INVESTIGATIONS IN FOREST PRODUCTS 



A field of investigation which is expanding tremendously in recent 

 years is that relating to forest products. The work is mainly directed 

 from headquarters in the Forest Products Laboratory at Madison, 

 Wisconsin. This laboratory, which is maintained in cooperation with 

 the University of Wisconsin, is one of the best of its kind in the world. 

 Laboratories are also maintained at Wausau, Wisconsin, and at 

 Seattle, Washington, and district stations have been established at 

 several points. Studies in this field fall under four heads — mechanical 

 and physical properties and structure of wood, wood preservation, 

 derived products, and statistical studies. 



The first class of studies includes those relating to strength of 

 structural timbers ; stiffness, toughness, hardness, specific gravity, 

 and other qualities of different woods, effect of air seasoning, kiln- 

 drying, and high temperature and pressure treatments. 



13 Review of Forest Service Investigations, 1913, 36: Forest Bui. 44, 91: Forest 

 Circ. 143: House Committee on Agriculture, "Report on the Influence of Forests 

 on Climate and Floods," by Willis L. Moore, 1910: Yale Review, 10, 241: Review 

 of Reviews, 47, 605: Proceedings, Am. Forestry Assoc, Sept., 1897, 133: Agr. 

 Yearbook, 1903, 279: Science, July 18, 1913, 63-75. 



