238 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. 



TURPENTINE. 



In 1902 a method was devised whereby it has become possible to 

 secure a materially larger yield and better quality of crude turpen- 

 tine, with indefinite prolongation of the formerly brief period of 

 years during which the crude material of the naval-stores industry 

 could be gathered from the same trees. Commercial operations on 

 the Florida National Forest have demonstrated that the naval-stores 

 industry may be perpetuated, instead of being destroyed through 

 the wasteful methods which have removed the industry from the 

 Carolinas where it started. At the same time a vast new field of 

 future naval supplies has been indicated through experiments con- 

 ducted on national forests in Arizona, California, and Colorado, 

 which have shown that western yellow pine may be utilized to sup- 

 plement the pine forests of the Southeast as producers of turpentine 

 and rosin. 



STRENGTH OF TIMBERS. 



Another great gain has been made through better knowledge of 

 the strength of the various kinds of timbers used in construction 

 and of the physical properties which determine the use to which 

 woods may be put. While some strength tests of timbers had been 

 made prior to 1897, the results had little applicability to construc- 

 tion work. Since 1902 systematic and exhaustive study of this sub- 

 ject has been under way, covering practically all native species of 

 commercial importance. Tests on the woods themselves and upon 

 wood products have led to utilization of various species formerly 

 disregarded and to large economies in consumption. 



NEW WOODS FOR PUL.P. 



From 1897 to 1913 the consumption of wood for pulp quadrupled. 

 At the beginning of this period three-fourths of all the pulp was 

 spruce, and less than one-fourth of it was imported. Now, with an 

 annual consumption of about 5,000,000,000 cords, 40 per cent is 

 spruce, and about half is imported. In this period the price of 

 spruce doubled. Exports of wood pulp have fallen off and imports 

 have increased fourfold. These figures point to the fact that if the 

 United States is to furnish its own supply of wood pulp it must do 

 so from substitutes for spruce. Tests made by the department show 

 that pulps of commercial value suitable for news and wrapping 

 paper can be made by the sulphite process from eight native woods, 

 several of which grow in quantitj^ on the national forests. Some of 

 these woods are beginning to be used to a limited extent. The de- 

 partment's activities also have proved that native species, large 

 quantities of which are available and cheap in the Lake States, can 

 be substituted for spruce in the ground-wood process for news print 



