167 



untrt-ated timbers in contact with treated structures, as previtnish- noted by Shackell 

 and others. 



TABLE 17 



DESCRIPTION OF CREOSOTED TE.ST PIECES ATT.\CKED THROUGH 

 UNTREATED BAIT PIECES 



* Heavily attacked by Bankia and Limnoria, but still holding together. 



t Completely destroyed, only fragments hanging to bolts. 



X The crowding of the borers in this bait piece was not as great as in the others. 



Studies of the Extent and Ch.\r.\ctkr of Losses from Creosote 

 under v.\rious conditions 



The following small scale tests were carried out for the purpose of finding the 

 amount and character of the loss of creosote constituents from treated wood exposed 

 in air and in sea water. They are not intended to be regarded as service tests, since 

 they do not quantitatively represent the losses from marine piling. They are, however, 

 satisfactory as indicating the qualitative changes in creosote under various conditions, 

 and to that extent they can probabh' be regarded safely as somewhat accelerated 

 service tests. 



For this stud>', ten test pieces were cut from a Douglas fir sapling. They were 

 about 6" in length by 5" in diameter, and were treated to refusal with a medium 

 weight creosote from the Republic Creosoting Company. The pieces were weighed 

 before and after treatment to determine the weight of oil absorbed. This was very 

 high, being from 25 to 30 pounds per cubic foot. 



Two of the pieces were exposed in the air and the rest were placed in the bay. 

 At the same time, portions of the original oil were exposed in the laboratory in open 

 dishes. The dishes and the air pieces were weighed from time to time to determine 

 the amount of loss. Pieces were also removed from the bay at intervals, and the oil 

 extracted and weighed. From the weight of oil recovered and the weight initially 

 present, the percentage of loss from these blocks can also be calculated. 



Figure 60 shows the rate of loss of creosote constituents from treated wood in 

 water, treated wood in air, and from the open dishes. All losses are corrected to the 

 same mass of oil and same evaporation surface. Table 18 shows the comparative 

 losses in the three cases after \-arious elapsed times. 



