8 



BULLETIN 1231, IT. S. DEPARTMENT OF AGRICULTURE. 



with Oil A, No. 2. Stakes under these treatments were numbered 

 from 109 to 193, and received the treatments shown in Table 3. 



T^ble 3. — Oils and processes used in impregnating Stakes 109 to 193. 













Oil A. 



Oil A. 



OilB. 



Wood creosote. 



Full-cell. 



Rueping. 



Full-cell. 



Rueping. 



Full-cell. 



Rueping. 



Special. 



Stake. 



Stake. 



Stake. 



Stake. 



Stake. 



Stake. 



Stake. 



117 



168 



112 



115 



110 



134 



109 



118 



169 



113 



119 



131 



150 



114 



121 



171 



126 



120 



132 



151 



122 



123 



172 



127 



124 



133 



152 



148 



125 



173 



128 



116 



147 



156 



174 



m 



177 



130 



138 



153 



157 



175 



149 



178 



135 



139 



155 



158 



181 



176 



179 



136 



140 



167 



159 



183 



182 



180 



137 



142 



170 



160 



186 



187 



184 



143 



146 



190 



162 



189 



188 



111 



185 



191 



145 

 166 



161 

 164 



192 

 193 



163 



165 









Treatment marked " Special " treated with oil to refusal. 



Stakes 129, 141, and 154 were missing. 



With these treated stakes were placed 22 untreated check stakes. 

 (See fig. 2 for arrangement of stakes.) 



Other .treated stakes have since been added to this test at irregular 

 intervals. 



Coal-tar creosote oils containing varying percentages (high and 

 low) of naphthalene and tar acids were included in the test treat- 

 ments, since it was formerly considered that a high percentage of 

 naphthalene in coal-tar creosote oils was more effective against marine 

 borers and that a high percentage of tar acids was more effective as an 

 antiseptic in preventing fungous decay. 



Some of the objections to coal-tar creosote as a wood preservative 

 are discoloration, odor, and smarting to eyes and touch, " sweating " 

 in hot climates, soiling clothes, and corroding rubber insulation; 

 that is, when conduits are impregnated with creosote, the creosote is 

 said to be injurious to the rubber insulation on cables. Wood treated 

 with creosote can not be painted or finished after treatment. 



Many of the objections can be avoided by proper treatment and 

 regulating the amount of creosote held in the wood by the " empty- 

 cell " or " open-tank " impregnation treatments. Impregnation with 

 coal-tar creosote is by far the most effective treatment for timber to 

 be placed in or in contact with the ground. Attack by termites to 

 a telephone pole line in Virginia is very slight (usually through 

 season checks) , after 25 years' service. By adding pigment to creo- 

 sote, as is done in the preservative treatment given shingles, a painted 

 effect can be obtained which does away with the brown discoloration, 



Description of Plate I. 



Experimental Work with Wood Preservatives and Damage to Resistant Redwood 

 and Woodwork in Buildings by Termites : 1, Section of woodwork in building 

 damaged by Cri/ptotermes breris at San Jose, Costa Rica. 2, An ineffective method of 

 wood treatment. Experimental ash block steamed 10 hours at 28 pounds pressure, after 

 6 months' tests buried in the ground with logs infested by Reticulitermes in Virginia. 

 3, Rocker of rocking chair damaged by C. brevis, Key West, Fla. 4, Homemade, crude 

 " open tank " plant at eastern field station. Falls Church, Va. 5, View of a portion of 

 the treated experimental stakes at Falls Church, Va.,. March, 1917. 6, One of several 

 fence posts of redwood (Sequoia .semperi-irens) (heartwood) damaged by the termite 

 BeticuUtermes liumilis var. hoferi from Sabino Canyon, Santa Catalina Mountains, Ariz. 



