514 DEPAKTMENTAL BEPOETS. 



and embodied in a complete report, with maps and photographic 

 illustrations. 



Cedak Shingle Industry. 



The cedar shingle industry of the Pacific Northwest was investi- 

 gated daring the fiscal year. The work included a study of the dis- 

 tribution of available supplies of shingle cedar, the scope and status 

 of the shingle industry, its consumption of timber, the relation of 

 present methods of cutting to future supply, and a study of cut-over 

 cedar forests in relation to reproduction. In addition to field inves- 

 tigations, circulars were sent out to secure data not otherwise attain- 

 able from cedar shingle manufacturers. Nearly all the manufacturers 

 addressed showed marked interest in the investigation. 



Dendeo-Chemical Investigations. . 



The work of the dendro-chemical laboratory was conducted in coop- 

 eration with the Bureau of Chemistry, the Bureau of Forestry paying 

 the salaries of experts and giving direction to the work, while the 

 laboratory and appliances and immediate technical and administra- 

 tive oversight were furnished by the Bureau of Chemistry. Investi- 

 gations were made during the past j'ear along the following lines : 



(1) Study of the commercial value of gums and resins from forest trees of the 

 Philippine Islands. 



(2) Study of the production of tannins by native barks and woods. Analyses 

 were made of the standard Chestnut Oak barks of the East and West and of the 

 black oaks of the East. A series of analyses was also made of the woods of these 

 trees to show their tannin content. 



(3) Study of untried pulp woods to determine their usefulness as substitutes for 

 standard woods now becoming scarce. 



Considerable time was spent as a preparation for this work in a study of the 

 stmctui-al and other characteristics of standard pulps, the felting qualities of 

 which are known to meet the requirements of various papers. Of untried or lit- 

 tle used woods, studies were made of the pulps produced by Black Gum, Cotton 

 Gum, Colorado Spruce, Black Cottonwood, Narrowleaf Cottonwood, Aspen from 

 the Rocky Mountains, and Engelmann Spruce. 



(4) Experiments to determine the effects of certain poisonous chemicals on the 

 life of trees. The purpose was to discover cheap and effective agents with which 

 to destroy noxious woody growth. 



Studies were also made of the damaging effects which illuminating and other 

 gases and fumes have on the roots and leaves of trees. This Bureau Is often asked 

 to supply exact information on this subject. Several important problems have 

 been presented for solution relative to the effects of fumes from smelters on the 

 foliage and the life of nearby forest trees. 



(5) Detection of adulterated spirits of turpentine. A thorough study was made 

 of several hundred samples of commercial turpentine from all possible sources for 

 the purpose of discovering a reliable test by which adulterated spirits could be 

 detected. The most extensively used adulterant was found to be petroleum. The 

 amount of spurious turpentine thus placed on the market is very considerable, 

 and is increasing so rapidly that the Savannah Board of Trade applied to the 

 Bureau for instructions as to how to detect the adulterated article. A simple and 

 reliable test has been found for detecting the smallest per cent of petroleum in 

 turpentine, and a description and illustration of the method has been prepared 

 for publication. 



Forest Entomology. 



Investigations in forest entomology were conducted by the Division 

 of Entomology in cooperation with this Bureau. The life histories and 

 depredations of forest insects were studied in the principal timber 

 forests of the East, South, and West for the purpose of devising methods 



