Current Literature. 551 



three generally are considered together because of their com- 

 mercial rather than their botanical relationship. 



"The woods of all have several points of similarity, such as 

 hardness, strength and susceptibility of fine polish, and in the 

 main their uses are similar. They grow usually in the same 

 regions, and they are often lumbered and milled almost as though 

 they were a single wood, but the resulting lumber is piled and 

 sold separately. It is not unusual in New England, the Ap- 

 palachian region, and the Lake States for lumbermen to speak 

 of beech, birch, and maple as "the hardwoods," 'thereby placing 

 them in a group by themselves, separate from oak, elm, gum and 

 the rest. This is especially true when beech, birch and maple 

 go to chemical plants manufacturing charcoal, wood alcohol, 

 acetates, and other by-products. These woods in 1909 constituted 

 more than 90 per cent, of all the hardwoods employed in dis- 

 tillation in the United States. They made up, also, a large but 

 unknown percentage of the country's hardwood flooring, material 

 for furniture and agricultural implements, and interior finish 

 for houses. In a variety of small commodities they hold first 

 place." 



The important species are considered in great detail. In each 

 case there is first a summation of the physical properties, the 

 data for which are taken largely from Sargent since the Forest 

 Service tests are not yet complete. "Engineers and others wish- 

 ing to obtain accurate values for the mechanical properties will, 

 of course, not use this bulletin for that purpose." 



The supply of material is next briefly considered, followed 

 by summary of the early uses. The remainder is devoted to 

 a well-written, and instructive consideration of the different uses 

 of each wood and the reasons for such uses. 



Some of the figures relating to supply are interesting. The 

 total remaining stand of beech in the United States is roughly 

 estimated at from 17 to 18 billion feet. The amount of sweet 

 birch "is probably much under that of beech, and certainly less 

 than sugar maple." "It has been estimated that enough paper 

 birch is in sight to meet visible demands for about 40 years." 

 The entire stand of maple, counting all species is placed at less 

 than 40 billion feet. "Well-posted lumbermen in Michigan are 

 of the opinion that maple in their state will be cut out in 15 

 years." S. J. R. 



