ABSORPTION AND PENETRATION OF COAL TAR AND CREOSOTE. 15 



Temperature of preservative a,nd pressure constant and the time of 



treatment varied. — (Tables 16 and 17 and fig. 8.) 



With the mixture containing 20 per cent tar and 80 per cent 

 creosote it was necessary to increase the treating period from two 



PENETRANCE TESTS. 

 (Data in Table 15.) 



8 



7 



S5 6 



: i 



!§ 5 

 'I 4 



w3 



£2 



1 















































i 

































































































< 



r~ 











__• 











































































































































































0.18 



< 











































I 









































0.16 



















































































0.14 



















































































0.12 





















i 



» 





















































e 









0.10 



















































































0.08 



















































































0.06 



















































































0.04 



















































































0.02 



















































































0.00 











































V "<» ( 



) 



4 





e 





i; 



» 



M 





2 



3 



2< 



% 



2( 



» 



3 



I 



31 



5 



40 



PERCENT OF TAR BY VOLUME 



tfiG. 7. — The relative absorptions and penetrations into longleaf pine using mixtures of creosote No. 6 and 

 tar No. 4. Time of treatment, 2 hours; pressure, 80 pounds per square inch; temperature of preservative, 

 180° F. 



hours to four hours to obtain the same absorption as when the 

 creosote unmixed with tar was used. A reduction in the average 

 11917°— 18— Bull. 607 3 



