144 EXPERIMENT STATION RECORD. 



Rubber culture.— I, Hevea brasiliensis, H. Zaepernick (KautschuJcJculturen. 

 Berlin, 191/f, vol. 1, pp. XV ^118, figs. 34).— This is the first of a series of works 

 dealing with rubber culture, and treats of the plantation culture and exploita- 

 tion of Hevea brasiliensis in various tropical countries. In addition to cultural 

 practice information is given relative to ta'pping operations, methods of coagu- 

 lating rubber, and estimates on the cost of producing plantation rubber. 



Suitability of longleaf pine for paper pulp, H. E. Surface and R. E. 

 Cooper (U. 8. Dept. Agr. Bui. 72 {1914), pp. 26).— This bulletin reports a series 

 of tests conducted at the U. S. Forest Products Laboratory, Madison, Wis. In 

 order to determine the suitability of southern pines for paper pulps, to ascertain 

 the efCects of varying cooking conditions in the sulphate process of pulp making, 

 and to compare the sulphate process with the soda process. 



Piesults thus far secured show conclusively that longleaf pine is well adapted 

 for the manufacture of natural-color kraft pulps and papers, and that the sul- 

 phate process of pulp making apphed to this wood affords products of better 

 quality and of higher yields than the soda process. Kraft papers can be made 

 from longleaf pine that are equal or superior in quality to the imported and 

 domestic kraft papers now on the market. The high gravity of the wood and 

 the resultant high yield of pulp per cord give longleaf pine an advantage pos- 

 sessed by few, if any other, commercially important woods suited for pulp 

 making. 



Uses for chestnut timber killed by the bark disease, J. C. Nellis {U. 8. 

 Dept. Agr., Farmers' Bui. 582 {1914), pp. 24, figs. 8).— This bulletin contains 

 information of value to wood-lot owners relative to the utilization of chestnut 

 timber that has been killed by the bark disease. Preliminary strength tests con- 

 ducted by the Forest Service upon chestnut killed by the bark disease indicate 

 that sound wood from dead trees is fully as strong as wood from healthy trees, 

 providing that the trees have not been injured by insects, decay, or checking. 

 Checking starts in small trees in the second year, and in all trees is rapid from 

 the fifth year on. In order that the timber may be placed on the market before 

 it begins to deteriorate it is advised that diseased chestnut be cut during the 

 first winter after infection. 



Bocky Mountain mine timbers, N. de W. Betts (Z7. S. Dept. Agr. Bui. 77 

 {1914), pp. ii4, figs. 7). — Bending and crushing tests of a number of kinds of 

 timber used in Colorado for mine beams, props, and caps are reported in tabular 

 form and discussed. Data are also presented as to the consumption and pro- 

 duction of mine timbers in Colorado, including production by species, the cost 

 for different sizes, and the life of mine timbers. The methods used in the 

 tests, together with data on individual crushing and bending tests are appended. 



The tests included green, air-dried, and fire-killed timber. They indicated 

 that air-dried mine props and caps are much superior to green ones as to 

 strength at the elastic limit, strength at maximum load, and stiffness. With the 

 exception of Douglas fir there seems to be as much variation in the strength of 

 one species procured in different places as among the dift'erent species them- 

 selves. This is attributed to defects which are usually found in material u.sed 

 for caps and props. The unit strength and stiffness of 16 ft. round beams de- 

 creased with an increase in diameter. Beams cut from timber standing dead 

 for about 30 years showed a strength intermediate between green and air-dried 

 material cut from live timber. The tests indicated that timber cut from dead 

 trees can be graded as to decay and defects on the same basis as other material. 



Tests of wooden barrels, J. A. Newlin {U. 8. Dept. Agr. Bui. 86 {1914), 

 pp. 12, pis. 6). — The author here reports tests of barrels made from quarter- 

 sawed white oak which were conducted in cooperation with the Bureau for 



