»;o4 



ANTISKI'TIC TKEATMENT OF TIMBER. 



Stems or poles, \Yitli their bark intact, are placed nearly 

 horizontally (fig. 295, a, a) on a timber framework ; the liquid 

 (1 part sulphate of copper to 100 parts of water) flows from a 

 vat h, which is supported on a trestle 26 to 32 feet high, passing 

 by the pipe m into the conducting tube n under the ends of the 



Fig. 29S 



^^ 



%=d-^ 



logs, and enters the logs through the gutta-percha tubes _/; each 

 tube having a separate tap. In order to prevent the liquid 

 from escaping by the anterior section of a log, a piece of hempen 

 rope is placed round its periphery and a board {d, d, fig. 29G) 

 l)laced over a rope and pressed firmly against the log by a press 

 // and two tension screws and nuts. The section of the log, the 

 hoard d and the piece of rope placed in a ring between them, 

 L-nclosc a hollow space with which the gutta-percha tube 

 communicates by means of an oblique augur hole bored in the 

 log. The solution of sulphate of copper llowing from the 



