FOREST SERVICE. 33 



reserves should lead to several new nurseries and to extensive plant- 

 ing by the rangers under technical supervision. The -new plantations 

 will demand complete fire protection, which will be planned for by 

 technical men and executed by the reserve officers. 



Planting on all the treeless i'eser\'es in the Middle West should 

 be started next spring with plant material from the Halsey nursery. 

 The Niobrara, North Platte, aiid Portales reserves need large experi- 

 mental plantations to determine whether local nurseries are called 

 for. In the Black Hills Forest Reserve broadcast sowing will* be 

 conducted on a larger scale if it continues to give promising I'esults. 

 A large quantity of tree seed for use at the planting stations will be 

 collected again this fall. 



DENDROLOGY. 



A large correspondence is entailed by requests for technical infor- 

 mation, especially as to the distinguishing characters of tree species, 

 native and foreign, and their economic products. Many identifica- 

 tions of wood, seed, and other specimens of nati^'e and foreign trees 

 are called for by individuals and educational institutions, and espe- 

 cially by builders, architects, and engineers, in consequence of the 

 frequent substitution on the mai-ket of inferior woods for stand .ird 

 building materials. In all, 3,36('. letters were prepared on den- 

 drology. 



TURPENTINE INVESTICiATIUNS. 



Experiments were continued during the turpentine season of 1905 

 to discover the effects of different methods of chipping on the yield 

 and on the life of the trees. Final results in suoh experiments 

 require data for several years, but the indications are that by chip- 

 ping a " streak " half as deep and half as high as in tlie present prac- 

 tise an equal or greater yield of turpentine per year ciui be obtainad, 

 and the working period can be doubled. 



Experiments to compare the results of the pre-ent method of 

 working and one under which only trees over 10 inches in diameter 

 are chipped with fewer " faces " showed that over 20 per cent more 

 turpentine was obtained from the latter method. If these results 

 are confirmed they will lead to a radical change of method, under 

 which a tract may be worked indefinitely. At present turpentining 

 lasts for but three or four years and virtually destroys the forest. 



A chemical study of the distinguishing characteristics of turpen- 

 tines from different species of pines Avas begun in cooperation with 

 the University of North Carolina. Commercial turi^entine is dis- 

 tilled without distinction from the resins of longleaf, Cuban, short- 

 leaf, loblollv, and pond pines, tho mainly from the first two. The 

 products of these several species differ chemically and otherwise, 

 which doubtless explains past failures to find a method for detectmg 

 adulterated spirits. The study will throw light on this matter, 

 but is expected to be chiefly valuable by showing which of the 

 species now worked (and possibly, also, new species) yield turpen- 

 tine in paying quantities, and which yields the most. This is 

 important in forest management, to determine which species should 



