236 TRANSACTIONS OF ROYAL SCOITISH ARBORICULTURAL SOCIETY. 



necessary according to the texture of the timber). After the 

 desired pressure has been reached, it is taken off, either 

 immediately or after a few minutes, and the oil is returned to 

 the overhead tank. After this the impregnating cylinder is 

 opened and the timber is found thoroughly penetrated by the 

 creosote, but perfectly dry and clean, the air pressure inside the 

 timber having opened up the pores of the wood to admit the oil, 

 and having then driven out the superfluous oil from the interior 

 of the pores of the timber and left only enough to impregnate the 

 walls of the cells, which is quite sufficient for preserving them." 



The aim is to saturate thoroughly the wood-fibre with the 

 preserving liquid, without leaving any of it in the open spaces 

 which these enclose, the result being that a smaller quantity 

 of liquid is required than under the ordinary process. It is 

 claimed that a deeper penetration is obtained, while the timber 

 is left so clean and dry that it can be handled immediately after 

 its removal from the cylinder, and can be painted after it has 

 been in use for some time. 



The advantages gained by the process are thus summarised : — 



1. A thorough saturation of the whole of that portion of the 



timber which can be saturated by the preserving liquid. 



2. The absorption of only so much liquid as is necessary 



to accomplish this. 



3. The oozing and sweating of wood is completely prevented, 



the timber being dry and clean. 



4. A great saving in cost without reducing the life of the 



timber. 

 The results of the process have been tested by Professor 

 Baron von Tubeuf, of the Munich University, who has reported 

 very favourably on it. Specimens of Riipingised wood may 

 now be seen at our Secretary's office, 19 Castle Street, 

 Edinburgh. 



Afforestation at Vyrnwy. 



The afforestation of catchment areas around reservoirs is an 

 undertaking of the highest importance, since the influence of the 

 forest is such that not only is the quantity of available water 

 increased, but the purity and regularity of supply are made more 

 certain. Many large corporations ^ have already realised these 



^ See vol. xxiii., pt. I., January 1910, p. 22. 



