18 



the species. It may be said now, however, that an extension of the turpentine 

 industry to the western yellow-pine belt is an assured possibility. The western tree 

 yields resin as copiously as do the long-used southern pines. 



Following further yield determinations of the turpentine and of its characteristics, 

 there remains only to be devised a practical method of "chipping" or tapping this 

 pine. The bark of the western tree is so thick that it can not be chipped with 

 the same tool ("hack") as is used on the thin-barked southern pines. There 

 appears, however, to be no insurmountable difficulty in devising a practicable method 

 of chipping the western trees. 



It is too soon to decide the probable commercial value of extending this industry 

 to western pine forests. The industry is sure, however, to add enormously to the 

 total profit of a pine forest, which can, as is now done in the South, be turpentined 

 for a term of years previous to lumbering. If turpentining is properly conducted 

 no appreciable damage results to the lumber subsequently cut from the trees. 



Accessions to the Library Compiled by the Librarian. 



Members of the Service are urged to report their special needs to the Librarian of 

 any literature required by their work, when steps will be taken to secure it- 

 Forestry General. 



The advance movement in Michigan forestry; Michigan forestry commission. 1905. 



36 p. (Ann Arbor, Mich. ) 



Destructive farming; G. E. Finch. 1906. 8 p. Illus. (Marion, Iowa.) 

 Der deutsche Wald, sein Werden und seine Holzarten (The German forest, its origin 



and tree species); X. Siefert. 1905. 22 p. (Druck der G. Braunschen Hofbuch- 



druckerei.'Karlsruhe. ) 

 The forestry work of the Ohio experiment station; W. J. Green and C. W. Waid. 1906. 



lip. Illus. (Ohio agricultural experiment station, Wooster, Ohio. Circular 50.) 

 Die forstlichen Verhaltnisse Kanadas (The forest situation in Canada); A. Scheck. 



1906. 122 p. (Deutsche Landwirtschafts-Gesellschaft, Berlin.) 

 What is forestry and what does it mean to the people of Michigan; F. Roth. 21 p. 



Illus. (Tradesman Company, Grand Rapids, Mich.) 



Educational. 



The course in forestry at the Oregon agricultural college. 1902. 20 p. Illus. (Ore- 

 gon agricultural college, Corvallis, Oreg. Bulletin, ser. 1, no. 13.) 



Forest Mensuration. 



Forest mensuration; H. S. Graves. 1906. 458 p. (J. Wiley and sons, N. Y. $4.) 



Statistical. 



Exports of farm and forest products, 1903-1905, by countries to and from which con- 

 signed. 1906. (U. S.Dep't. of agriculture Bureau of statistics. Bulletins 45 and 

 46.) 



Trade with noncontiguous possessions in farm and forest products, 1903-1905. 1906. 

 45 p. (U. S.Dep't. of agriculture Bureau of statistics. Bulletin 47.) 



Forest Insects. 

 Irrigation. 

 Arbor Day. 



The western pine-destroying bark-beetle; J. L. Webb. 1906. 14 p. Illus. (U. S. 

 Dep't. of agriculture Bureau of entomology. Bulletin 58, pt. 2. ) 



Practical information for beginners in irrigation; S. Fortier. 1906. 40 p. Illus. 

 (U.- S.Dep't. of agriculture. Farmer's bulletin 263.) 



Arbor day exercises in public schools of separate circulars for 14 states. 



The state engineer and his relation to irrigation; R. P. Teele. 1906. 99 p. (U. S. 



Dep't of agriculture Office of experiment stations. Bulletin 168.) 

 United States Reclamation Service. Fourth annual report, 1904-5. 1906. 374 p. 



Illus. (Washington, D. C. ) 



Soil Physics. 



Studieu \iber die naturlichen Humusformen und deren Einwirkung auf Vegetation 

 und Boden. (Studies of the natural humus forms and their influence on vegeta- 

 tion and soil); P. E. Muller. 1887. 324 p. Illus. (J. Springer, Berlin.) 



