290 



FOREST PRODUCTS 



season with difficulty and if piled too open and exposed to the sun's ray 

 may split and check very seriously. 



The following table shows the rate of seasoning for peeled hemlock 

 ties, stacked in 7 by 2 forms and surrounded by othef piles. They were 

 cut in the winter, but showed no apparent loss in weight up to the time 

 of initial weighing: 1 



The warmer and drier the air and the greater the circulation of air 

 currents, the more rapid will be the loss of water from the ties and con- 

 sequently its rate of seasoning. Ties, therefore, season more quickly in 

 the South than in the North and more rapidly in summer than in winter. 

 Ties should never be piled to season on low, swampy ground, or where 

 there is not a good circulation of air currents. Piling in or near a rank 

 growth of grass or weeds should always be avoided and piles should be 

 elevated above the ground on two cull ties or by some other means to 

 permit freedom of air currents underneath. 



There are many forms of piles in common use. Some are shown in 

 the accompanying illustration. The following are the principal forms 

 used by our railroad systems: 



(a) Solid piling, arranging 7 to 9 ties each way, with no spacing 

 and, therefore, little chance for circulation of air. This is rapidly going 

 out of practice, as it results in too slow a rate of seasoning. 



(b) Half-open piling, in which about 4 in. of spacing is allowed between 

 the ties, which are placed seven in a tier, each way. Not advocated, as it 

 is still too close for proper seasoning. 



(c) Triangular piling. Advocated where most rapid seasoning is 

 desirable and where plenty of piling space is available. Costs more 

 than other forms and is little used. 



1 See " The Seasoning and Preservative Treatment of Hemlock and Tamarack Cross 

 Ties," by W. F. Sherfesee, U. S. Forest Service Circular 132, p. n. 



