vii.] THE "DRY-ROT" OF TIMBER. 191 



brick wall, or foundation, which has only stood long 

 enough to partially dry. If there is no current of 

 diy air established through this part, nothing is more 

 probable than that the spores will germinate, and the 

 mycelium spread, and in the course of time it may 

 be months afterwards a mysterious outbreak of 

 dry-rot ensues. There can be no question that the 

 ends of beams in new houses are peculiarly exposed 

 to the attacks of dry-rot in this way. 



The great safeguard beyond taking care that no 

 spores or mycelium are present from the first is to 

 arrange that all the brick- work, floors, &c., be 

 thoroughly dry before the timber is put in contact 

 with them ; or to interpose some impervious substance 

 a less trustworthy method. Then it is necessary 

 to aerate and ventilate the timber ; for dry timber 

 kept dry is proof against " dry-rot." 



The ventilation must be real and thorough however, 

 for it has been by no means an uncommon experience 

 to find window-sashes, door-posts, &c., in damp 

 buildings, with the insides scooped out by dry-rot, 

 and the aerated outer shells of the timber quite sound : 

 this is undoubtedly often due to the paint on the outer 

 surfaces preventing a thorough drying of the deeper 

 parts of the wood. 



Of course the question arises, and is loudly urged, 



