BUREAU OF FORESTRY. 199 



mines, and it is probable that this timber will be increasingly utilized 

 for this purpose. Investigations on a small scale have been carried on 

 to determine the best sizes for this use. 



Little is known at the present time as to how to preserve the red or 

 Douglas hr. In cooperation with the Northern Pacific Railroad, tests 

 were begun in March to determine the actual weights of green and dry 

 wood as the first step in a comprehensive study of this tree. 



It has already been found that at Pasco, in a semiarid region, ties 

 evaporate water in the first few weeks after cutting nearly six times 

 as rapidly as at Taconia, in a region of very heavy rainfall. Various 

 forms of piles have been constructed, preliminary figures obtained, 

 and important results are expected. 



A series of important treating tests were carried on in cooperation 

 with the Chicago, Burlington and Quincy Railroad, at Sheridan, Wyo., 

 chiefly as to the treatment of lodgepole pine timber with zinc chlorid, 

 with and without preliminary steaming, which appears, so far, to have 

 little effect on penetration. A beginning was also made in testing red 

 fir and western yellow pine from the Black Hills, South Dakota, and 

 this work will be vigorously followed up during the coming year. 



A second series of investigations carried on at the Sheridan treating 

 plant dealt with the rapidity with which zinc chlorid leached out from 

 treated ties. The results show that ail timbers treated with zinc chlorid 

 should be seasoned until approximately air dry. Recommendations to 

 this effect have been generally followed bj^ those emploj'ing this form 

 of preservative treatment. 



CENTRAL. 



The studies in timber preservation carried on in the Central States 

 were in general aim similar to those already described. In the Miss- 

 issippi Valley a large number of timbers, especially red, pin, water, 

 and other oaks, beech, red gum, sj'camore, etc., are being consid- 

 ered as possibilities for use in many industries, because of the rapid 

 exhaustion of the supply of white oak and hickory. In cooperation 

 with the St. Louis and San Francisco and the Illinois Central railroads 

 a general ioAestigation was begun during the year as to the utilitj'^ of 

 these timbers for ties and bridge structures. With chemical treatment 

 it was found perfectly practicable to use them both for ties and for 

 other forms of construction, and it is proposed to extend these inves- 

 tigations to strength determinations during the coming j^ear. 



A series of tests was inaugurated similar to those carried on in the 

 West to determine the relation between seasoning and the season of 

 cutting. The chief object is to ascertain how to season these woods so 

 that they will not check, split, or warp excessively, and to protect 

 them against excessive rainfall. Approximately 500 ties of as many 

 different timbers as could be obtained were cut each month at various 

 stations, and weighed at regular intervals until they were air dry. A 

 distinction was made between swamp timber and that cut on high 

 ground. 



Tests of hill red oak were made at Black Rock and Imboden, Ark., 

 and of bottom red oak and red gum at Portia and Beggs, Ark. In 

 six to eight months the red oaks have lost from 2.5 to 30' per cent in 

 weight. Ties under roofed piles have shown little tendency to check, 

 split, or warp. Most of the timbers lost the bulk of their moisture in 



