38 DEPAETMENTAXi REPOKTS. 



impartial information. It has been able to discourage fraudulent 

 methods and the investment of capital in processes founded on an 

 unsound basis, and now largely directs the trend of investigations 

 and practice in this country. It has obtained results of practical 

 value to the small consumer by the discovery of a simple and prac- 

 tical method for preserving fence posts, shingles, and other farm 

 timbers. The entire expense of extensive investigations is borne by 

 the cooperators. 



Study of the general subject of wood preservation involves attack 

 upon a series of subordinate problems which center in the seasoning 

 of wood. Precise knowledge of the rate at which seasoning takes 

 place and the effect of such modifying factors as previous water-soak- 

 ing, different methods of exposure to the air, time of year when the 

 timber was cut, and the conditions under which it was grown, is 

 essential in order to devise the best practical methods of preserving 

 wood. All of the experimental timber collected in connection with 

 the projects was weighed at regular intervals. A considerable por- 

 tion of it was accurately measured when freshly cut, when partially 

 seasoned, and when air-dry — and in this way exact data on the shrink- 

 age and the rate of seasoning were obtained. After treatment the 

 material experimented upon was in each case put into service under 

 conditions which will test the relative preserving power of the differ- 

 ent processes. 



WORK COMPLETED. 



The following work was completed during the year : 



Experiments in seasoning and treating arborvitse telephone poles 

 at Escanaba, Mich., in cooperation with the American Telephone and 

 Telegraph Company, and chestnut poles at Parkton, Md., in coopera- 

 tion with the same company, resulted in a practical method for treat- 

 ing these poles on a commercial scale. 



Experiments on yellow pine cross-arms at Norfolk, Va., made it 

 possible to devise a system for handling,, grading, seasoning, and 

 treating this and similar classes of material which will insure cheaper, 

 stronger, and more durable timber. 



Experimental treatment of hemlock and tamarack cross-ties at the 

 plant of the Chicago and Northwestern Railway Company, under 

 cooperation with the company, resulted in a complete series of recom- 

 mendations for the handling and treatment of the ties from the time 

 they leave the woods until they are finally placed in the track. A 

 marked improvement in the efficiency of the plant has followed, 

 though there has not yet been time for all the recommendations to be 

 put into effect. 



Seasoned Douglas fir, western larch, and giant arborvitse ties, part 

 of which had been treated, some with creosote and some with zinc 

 chlorid, were laid in the track of the Northern Pacific Railway Com- 

 pany for a test of durability and of the effectiveness of different 

 kinds of tie plates and other devices for reducing mechanical wear 

 by the rails. 



Dead lodgepole pine fence posts from the Henrys Lake National 

 Forest were treated with creosote in an open iron tank to discover the 

 most efficient process at the lowest cost. The work was very success- 

 ful and will have practical value to the ranchers and other timber 

 users of the region. 



