Current Literature. 253 



ington. Both lots of ties came from the same place and the 

 weights were taken at the same time, but the seasoning was more 

 rapid and a lower rate was reached in the drier climate at Pasco 

 than at Tacoma. 



Of the eastern conifers only hemlock and tamarack ties from 

 Michigan have been tested. The hemlock had a very high mois- 

 ture content when green and lost water rapidly during the sum- 

 mer months but did not reach a constant weight within the period 

 of the observation which varied from ii to 16 months. There 

 appeared to be practically no difference in the rate of seasoning 

 of ties openly piled (7x2 and 8x1) and those closely piled (7^:7). 

 It required from 4 to 9 months, according to the time of year, 

 to reduce the moisture content of hemlock from a green weight 

 of 55-57 pounds per cubic foot to 40 pounds, while the average 

 dry weight of the wood is only 24 pounds per cubic foot. 



Seasoning records were obtained on loblolly, longleaf, and 

 shortleaf pine at Silsbee, Texas, and on loblolly at Ackerman, 

 Mississippi. Ties cut in January and February were fairly dry at 

 the end of 4 or 5 months, but continued to lose weight for several 

 months longer. From April to October the seasoning was so 

 rapid that the ties lost little weight after the first 2 or 3 months, 

 even if held till the following summer. 



Tests were also made on some southern hardwood ties. Hard- 

 woods in general dry more slowly than conifers. Red oak ties cut 

 in Arkansas in spring and early summer were far from dry when 

 they ceased to lose weight at the approach of winter, and the 

 following summer they lost nearly two-thirds as much moisture 

 as during the first summer. When the ties were cut in winter 

 and carried through two years the loss of weight during the 

 second summer was nearly half that of the first. The tests on 

 other hardwoods were not conclusive but indicated that red gum 

 and beech dry faster than red oak. 



Data on the rate of seasoning of northern hardwood ties are 

 very meagre. The data on the pole-seasoning tests will not be 

 reviewed here as they are presented in the present publication in 

 only slightly different form from Bulletin 84, "Preservative 

 Treatment of Poles." 



The accelerating effect of wann, dry weather on the rate of 

 evaporation, and the retarding effect of cold, damp or wet weather 

 are plainly visible in the tests started at different times of the 



