FORESTED 243 



by borers. The creosote had leached out and discolored the soil to certain 

 extent around some of the cottonwood, willow, and sycamore iwsts. 



A test of the effect of storage conditions on the \itality of forest tree seeds 

 indicates that the vitality is low after they have been stored for two years, and 

 that the proper methotl of storing forest tree seeds will depend upon the species 

 to which any particular seed may belong. 



The preservation of structural timber, H. F. Weiss (Neio York and London: 

 McGraic-Hill Book Compamj, Inc., 1915, pp. XVIII-{-312, pis. 47, figs. 32).— A 

 text-book and manual of information dealing with the wood preserving Industry, 

 the subject matter being based largely on lecture notes prepared by the author 

 for civil engineering students at the University of Wisconsin. 



The introductory chapter deals with the importance and history of wood 

 preservation. The succeeding chapters discuss the factors which cause the 

 deterioration of structural timber, the effect of the structure of wood upon its 

 injection with preservatives, the preparation of timber for its preservative 

 treatment, processes and preservatives used in protecting wood from decay, 

 the construction and operation of wood preserving plants, prolonging the life 

 of cross-ties from decay and abrasion, prolonging the life of poles and cross- 

 arms from decay and insects, prolonging the life of fence posts from decay, 

 prolonging the life of piling and boats from decay and marine borers, prolong- 

 ing the life of mine timbers, paving blocks, shingles, lumber, and logs, the 

 protection of timber from fire and minor destructive agents, the strength and 

 electrolysis of treated timber, and the use of substitutes for treated timber. 

 Considerable information dealing with wood preservation, wood preserving 

 processes, and data on the wood preserving industry of the United States, etc., 

 is appended. 



The deterioration of lumber. — A preliminary study, M. B. Pratt (Cali- 

 fornia >Sta. Bill. 252 {1915), pp. 301-320, figs. S).— In the study here reported 

 lumber from three important timber species, viz, sugar pine (Piniis lam- 

 hertiana), western yellow pine (P. ponderosa), and Douglas fir (Pseudotsuga 

 iaxifolia), was under observation in the yards of a representative lumber com- 

 pany in the northern part of the Sierra Nevada Mountains of California from 

 the time it left the sawmill until it was shipped. Data were secured relative 

 to the loss in grade due to air seasoning, kiln drying, and finishing, and the 

 cau.ses leading to the loss. « 



The limited amount of data secured in this work show that the upper grades 

 of sugar pine deteriorate much more in seasoning than either western yellow 

 pine or Douglas fir. The average loss for all lumber tallied in unfinished upper 

 grades of sugar pine through fall seasoning was approximately $12 per thou- 

 sand board feet as compared with an average loss of $2..5S per thousand board 

 feet through summer seasoning. One test in kiln drying sugar pine at the same 

 temperature as western yellow pine and Douglas fir indicated that the deteriora- 

 tion in the upper grades of sugar pine lumber would be much less if kiln dried 

 than when air dried in the spring or fall. Until tlie matter of kiln drj-ing of 

 sugar pine has been worked out more satisfactorily, however, it seems preferable 

 to air dry the summer-cut stock. 



Blue stain and brown stain, the greatest sources of depreciation in sugar 

 pine lumber, are largely the result of i)oor drying conditions due to imperfect 

 circulation of air, poorly drained soil, failure of a pile to shed rain water, 

 or damp, rainy weather. The author concludes that since a large loss is 

 liable to occur in air-.seasoned sugar pine owing to the sensitiveness of the 

 wood to blue stain and brown stain the value should be fixed in accordance 

 with the ultimate grade and value of the species rather than its grade and 

 value at the saw. 



