EVALUATION OF WOOD PRESERVATIVES 



463 



boiling above 315°C — as a base for calculation, along with the change 

 in residue determined from extracted creosote, von Schrenk, Fulks and 

 Kammerer estimated the creosote losses, above and below ground line, 

 for five poles from the Washington-Norfolk line, that are shown in Table 

 XVIII . The poles were old growth longleaf pine, with a high heartwood 

 volume. They were heavily treated — to about 16 pounds — by a full 

 cell process. There is a wide variation in the results shown in the table 



Table XVIII — Creosote Losses, Based on Residue 

 Increase, from Southern Pine Poles 

 9 years exposure; Washington-Norfolk line, American Telephone and Tele- 

 graph Company — Data of von Schrenk et al. 



Table XIX — ^ Creosote Losses, by Extraction 

 Southern pine test posts, aerial sections; 1926 and 1927 series; Gulf port test 

 plot — BTL (Waterman) data. 



Exposure period, months 



17 22 31 32 46 



Average loss, per cent 



1926 Series 



8 lb empty cell 



12 1b full cell 



"Light" oil 



"Mixed" oil 



1927 Series 



"Light" oil 



8 lb empty cell 



12 lb full cell 



"Heavy" oil 



8 lb emptv cell 



12 1bfuircell 



54 

 34 

 55 



38 



