AMERICAN WOOD-PRESERVERS' ASSOCIATION 7 



a dormant condition. On the other hand, a rise of temperature of but 

 a few degrees above the optimum has a greater influence on growth 

 than a corresponding reduction. The practical purposes, however, we 

 may say that nature so regulates temperature conditions that for the 

 region under consideration the fungi find a very favorable environment 

 over a considerable portion of the year. 



Control of Decay in Stored Ties 



With the foregoing considerations in mind relative to present 

 commercial practices as coupled up with the fundamental conditions 

 necessary for decay, it is seen that relief can only be secured by 

 changing commercial practice as far as possible so as to eliminate 

 infection and put the timber in a moisture condition unfavorable for 

 subsequent decay. 



Winter Cutting and Barking. The advantages in winter cutting 

 lie in the fact that at this season both temperature and humidity are 

 much less favorable for infection. It is true that air seasoning will 

 be much slower at this season, but this can be increased by removal 

 of the bark, which is also of advantage in controlling insect depreda- 

 tions. Slower seasoning is of particular value from a pathological 

 standpoint, as it decreases the number and size of season checks which 

 collect and retain moisture and thus offer favorable points for infection. 



Proper Piling in Woods. At points of production ties should 

 never be piled directly on the ground or allowed to lie about singly 

 on the ground for more than a few days at most. Forest soil is full of 

 living fungus, and being moist, infection is quickly carried over to 

 timber in contact with it. In piling or yarding ties they should be 

 placed on foundations well off the ground and amply ventilated beneath, 

 the ties being spaced so as to allow as much ventilation as possible 

 without undue checking. This preliminary seasoning in the woods is 

 of very great importance, as apparently a large amount of subsequent 

 decay is to be attributed to infection in the woods. 



Transport of Ties. With partially seasoned ties rail transport 

 would appear preferable to rafting from a pathological standpoint, 

 but perhaps not from a practical, for every time a tie is wet it is put 

 in a good condition for infection. The writer, however, does not wish 

 to lay too much stress upon this point, as proper yarding and piling 

 at destination will normally take care of the situation. 



Yarding Ties at Destination. Inasmuch as ties may be stored for 

 sometimes more than a year at terminal yards, careful attention must 

 be given to piling them, particularly when they are rafted. Since many 

 of the yards are on comparatively low ground, the first care must be 

 given to drainage so that all rainfall or ground water may be im- 

 mediately removed by seepage. A slag or cinder covering to a depth 

 of 6 to 12 inches makes a very good surface which keeps the weeds 

 down and allows rapid run off. 



