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FORESTRY INVESTIGATIONS U. S. DEPARTMENT OF AGRICULTURE. 



AMERICAN WOODS. 



The great variety of trees already enumerated furnishes almost as great a variety of charac- 

 teristic woods. There is, perhaps, no country in the world which can command such a wealth of 

 woods for strictly useful purposes, although the Tropics may yield a larger variety of ornamental 

 woods. The work of the Division of Forestry has concerned itself largely with the study of 

 American woods, the crop of American forests. It is, therefore, appropriate to include in this 

 report a brief resume, giving a description of the various kinds of wood and their present 

 application in the arts, reproduced from Bulletin 10. 



In the countries of Europe the kinds of wood used in construction and manufacture are so 

 few that there is but little difficulty in distinguishing them. In our own country the great variety 

 of woods, and of useful woods at that, often makes the mere distinction of the kiud or species of 



100 110 120 130 140 ISC 



Fio. 2 Diagram showing comparative progress of diameter growth in average trees. 



tree most difficult. Thus there are at least eight pines (of the thirty-five Dative ones) in the mar- 

 ket, some of which so closely resemble each other in their minute structure that they can hardly 

 be told apart; and yet they differ in quality and should be used separately, although they are 

 often mixed or confounded in the trade. Of the thirty-six oaks, of which probably not less than 

 six or eight are marketed, we can readily recognize by means of their minute anatomy at least 

 two tribes the white and the black oaks. The distinction of the species is, however, as yet 

 uncertain. The same is true as to the eight kinds of hickory, the six kinds of ash, etc. Before 

 we shall be able to distinguish the wood of these species unfailingly more study will be neces- 

 sary. The key given in the present publication, therefore, is by necessity only provisional, requir- 

 ing further elaboration. It unfortunately had to be based largely on external appearances, which 

 are uot always reliable. Sometimes, for general practical purposes, this mere appearance, with 



