FOREST SERVICE. 37 



now receives marked and growing recognition. Treating plants are 

 multiplying, and new methods and processes are being taken up. 

 ]n this work the Forest Service has become a recognized source of 

 aid and information. 



The study of fence-post treatment with creosote in open tanks was 

 carried further by experiments in southern California with eucalv])- 

 tus, and in Iowa, in cooperation with the State college, with rapid- 

 growth hardwood posts. 



The seasoning of red fir, western hemlock, and western larch rail- 

 road ties in Washington and Idaho, in cooperation with the Northern 

 Pacific Railway, is now finished, and the seasoned ties, part of which 

 have been treated, are ready to be laid in the track for a durability 

 test. 



Seasoning and treating experiments with' hemlock and tamarack 

 ties in Michigan, in cooperation with the Chicago and Northwi>slern 

 and "Wisconsin Ceaitral railways, have shown that seasoning before 

 treatment is highly advantageous. These experiments, which include 

 tests of the effect of soaking before seasoning, will be continued for 

 the coming year. 



Arborvita^ and chestnut telephone poles, cut each month of the year, 

 are now seasoning in Michigan and Maryland, respectively. In the 

 latter State a soaking test is included. When seasoned, part of these 

 poles will be treated and their comparative durability tested in service 

 alongside of untreated and unseasoned poles. At Norfolk, Va., lob- 

 lolly pine cross arms, cut each month, are undergoing experiment in 

 soaking, seasoning, and grading preliminary to treatment. The im- 

 portance of grading as the proportion of sapwood varies has been 

 demonstrated. Both these classes of experiments are conducted in 

 cooperation with the American Telephone and Telegraph and the 

 Postal Telegraph-Cable companies. 



A cooperative study of seasoning and treating poles and ties of 

 California western yellow pine, western red cedar, and eucalyptus, 

 and a similar study of loblolly pine mining timber used in Pennsyl- 

 vania, were begun. The latter has already shown that timber should 

 be peeled and seasoned for at least tAvo months before shipment, and 

 that open-tank treatment gives remarkably complete penetration of 

 the preservative. 



Addresses were given before the annual meetings of the Wood Pre- 

 servers' Association, the American Railway Engineers and Mainte- 

 nance of Way Association, and the North Carolina Pine Association. 



The Forest Service does no Avork in wood preservation except in 

 cooperation A^•ith those interested in the results. Every project has 

 been subjected to careful and frequent inspection. The cost of the 

 investigations are borne mainly, and in new work must be met almost 

 entirely, by the coojDcrators, but the results are for the public use and 

 are controlled by the Service, which seeks only the solution of prob- 

 lems of broad and general importance. 



DENDKO-CHEMISTRY. 



During the study of Michigan hemlock and tamarack ties, already 

 mentioned, there were made chemical analyses resulting in over 580 

 zinc estimations, to discover the penetration of zinc chlorid, and micro- 

 scopic examinations and measurements to learn the value of glue 



