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UNITED STATES DEPARTMENT OF AGRICULTURE 
S^y^Lru 
BULLETIN No. 606 
Contribution from the Forest Service 
HENRY S. GRAVES, Forester 
Washington, D. C. 
PROFESSIONAL PAPER 
April 15, 1918 
RELATIVE RESISTANCE OF VARIOUS HARD- 
WOODS TO INJECTION WITH CREOSOTE. 
By Clyde H. Teesdale, in charge, Section of Wood Preservation, and J. D„ 
MacLean, Assistant Engineer in Forest Products. 
CONTENTS. 
Page. 
Purpose of the experiments 
Structure of the hardwoods 
Methods used in the experiments. 
Apparatus 
Materials used 
Method of applying the creosote. . 
Factors affecting penetration — 
Effect of structure on penetrance . 
Grouping of species 
Relation of grouping to commercial treatment 
Conclusions 
Appendix 
Characteristics of the various species and 
results of treatment 
Bioiiography 
Page. 
11 
16 
17 
18 
IS 
34 
PURPOSE OF THE EXPERIMENTS. 
When wood is impregnated with preservatives some species are 
more easily penetrated than others, so that for proper treatment the 
species should be grouped according to their relative resistance to 
injection. Otherwise, part of a cylinder charge might receive a 
heavy treatment and another part a very light one. As wood struc- 
ture is the most important factor in the grouping of woods for treat- 
ment, the Forest Service has made a study to determine its influence 
upon penetration with creosote. Such factors as the amount and 
location of sapwood, the moisture content, and the like, encountered 
in the commercial treatment of wood, also have an important bearing 
Note. — Acknowledgment is made to Miss Eloise Gerry, microscopist, Forest Products 
Laboratory, for the portions of this bulletin describing the structure of the broad-leaved 
trees, and for assistance in examining the specimens after treatment. Acknowledgment is 
also made to Mr. F. J. Angier, superintendent timber preservation, Baltimore & Ohio 
Railroad Co. ; Dr. Irving W. Bailey, Harvard University ; Mr. John Foley, forester, 
Pennsylvania Railroad Co. ; Dr. Kendrick W. Hatt, professor of civil engineering, Purdue 
University ; Mr. A. R. Joyce, of the Joyce-Watkins Co. ; Mr. V. K. Hendricks, assistant 
chief engineer, and Mr. O. C. Steinmeyer, supervisor of timber preservation, St. Louis 
& San Francisco Railroad ; and Mr. J. H. Waterman, superintendent timber preservation, 
Chicago, Burlington & Quincy Railroad, for their generous assistance in reviewing the 
bulletin. 
11061°— 18— Bull. 606 1 
