10 BULLETIN 1231, U. S. DEPARTMENT OF AGRICULTURE. 
of the site, and the geographical situation. Coal-tar creosote and 
carbolineums have been found to be the most effective preservatives. 
Several coats of coal-tar creosote brushed on timber will add from 
2 to 5 years to its life. In the tests at Falls Church, Va., brushing 
with coal-tar creosote (three coats applied hot) was more effective in 
preventing attack by termites than was dipping in the hot preserva- 
tive. As has been stated, much depends upon the preservative. 
: Bod Soe 
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CHARRED. 
mem ==L/PPING WOOD CREOSOTE. 
—=-—L/PP/ING CORAL TAR CREOSOTE. | 
semoe—0e/PL/NVG CARBOL/NEUM. 
——GRUSHING 3 COATS CORE - 
TAR CREOSOTE. 
0 e SRUSHING 3 COATS WOOD CREOSOT? 
9 eoereeeeZPUSHING 3 COATS CARBOLINEUM 
lIWE [HP (H# (HE (H6 (87 /H8 1H9 1920 1924 7922 
SUPERFICIAL TREATMENTS. 
Fic. 3.—Comparison of the relative resistance to attack by termites of chemical 
wood preservatives and methods of treatment, Falls Church, Va., 1912-1922. 
Heavy or thick coatings of tar for the bases of an or posts are 
not effective and are valueless as preservative treatments. Many 
patented or proprietary preservatives or methods failed after short 
periods of test and are not referred to, except in a few cases. 
IMPREGNATION TREATMENTS. 
Methods by which the preservative is more thoroughly impreg- 
nated into the wood more permanently protect wood from insect at- 
tack, These methods of course are more expensive. Inspections of 
