60 



BULLETIN' 1036, U, S. DEPARTMENT OF AGEICLTLTURE. 



Messrs. Von Schrenk, Fulks, and Kanunerer, using the pitch 

 residue of the average creosote before treatment and the pitch 

 residue of the individual creosotes after treatment, estimate the loss 

 by volatilization to be as shown in Table 21. 



Table 21. — -Loss of creosote by volatilization from telegraph poles. 



Pole No. 



Section 

 of pole. 



Loss, 

 per cent. 



Pole No. 



Section 

 of pole. 



Loss, 

 per cent. 



10,749 



10,749 



29 



29 



1,425 



Top. 

 Butt. 

 Top. 

 Butt. 

 Top. 



59.0 

 20.8 

 42.4 

 16.4 

 43.3 



1,425 

 2,931 

 2,931 

 9,709 

 9,709 



Butt. 



Top. 



Butt. 



Top. 



Butt. 



2.7 

 58.0 

 32.8 

 70.8 

 60.3 



The same investigators analyzed the oils extracted from the north 

 and south sides of two poles; but, on account of lack of concordance 

 in results, they could not state definitely whether there was any 

 difference m evaporation corresponding to the difference in these two 

 points of the compass. They also made a few analyses to determine 

 the difference in evaporation near the surface and in the interior of 

 the treated portions. Their results show a slight but gradual in- 

 crease in the volatility of the creosote extracted from the center 

 over that obtained from the outer portions; but the investigators 

 state that more analyses should be made. 



Even an average analysis of the creosote is not usually available. 

 If, therefore, it is desired to determine the loss by volatilization, 

 another assumption must be made. Much of the treated wood 

 examined after long service is piling. In a pile there are three 

 different parts that represent three different conditions of exposure — 

 first, that part of the pile exposed to the air, or the ah- section; second, 

 that part of the pile that is in the water, or the water .section ; and, 

 third, the point of the pile, which is in the mud, or the mud section. 

 The mud section is less likely to change than either of the other two, 

 since the loss by evaporation and the loss by solution are both nearly 

 negligible. The assumption that there is no appreciable loss of the 

 creosote in the point seems, therefore, to be justifiable; at any rate, 

 the figures obtained by using this assumption would be less instead^ 

 of greater than the actual loss, even if the assumption is liable to be^ 

 considerably in error. Basing calculations on these two assumptions, 

 namely, that the fractions above 270° C. do not disappear appre- 

 ciably, and that the creosote in the point is the same as the original 

 creosote, the calculations shown in Tables 22 and 23 have been made 

 to show the losses occurring from piling that has been in service for 

 different lensrths of time under different conditions. 



