414 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE, 



Physical Studies. — In cooperation with the Alabama "Wood 

 Presorvino; Company, of Birmini!;ham, Ala., a design for a timber- 

 treating plant was prejiared, and a portion of the preliminary con- 

 struction work siij)erviseil b}^ a representative of the Forest Service. 

 The work was closed during the year. Tiie design and experimental 

 operation of timbiu'-treating plants in cooperation with the Tennessee 

 Coal and Iron Company, of Birmingham, Ala., was brought to a suc- 

 cessful end on May 1, 1910, after designs for two treating plants 

 submitted to the company had been accepted and the construction 

 and experimental operation of both of these plants supervised by a 

 representative of the Forest Service. The fmal report covering this 

 work is in preparation. In the work in cooperation with the Indian- 

 apolis, Columbus and Southern Traction Company, at Columbus, Ind., 

 inaugurated in 1908 and actively entered upon one 3^ear later, a repre- 

 sentative of the Forest Service supervised the construction of a tie- 

 treating plant designed by the Service, and operated it experimentally 

 until October 12, 1909, when the methods of treatment were thor- 

 oughly established and cooperative work was terminated. 



Considerable attention was devoted to the design and construction 

 of apparatus for the prevention of sap stain. A report giving recom- 

 mendations for future policy and preparing a design of equipment for 

 use was prepared. The final form to be given the proposed plant, 

 however, awaits further investigations of the methods or preventing 

 sap stain in lumber, tests of which are to be carried out at the labor- 

 atory. 



Engineering Studies.- — The tests to determine the effect of pre- 

 servative treatment upon the strength of yellow-pine timber, con- 

 ducted in cooperation with the Illinois Central Railroad, were com- 

 pleted. Longleaf and shortleaf pine bridge stringers and railroad tics 

 of a number of species were tested. Some of the investigations made 

 are published in a report of the committee on wood preservation of 

 the American Railway Engineering and Maintenance of Way Asso- 

 ciation. It was found that steaming at low pressures, such as 30 

 pounds to the inch, saturates the wood and renders it weak, but that 

 the strength to a large extent returns on subsequent drying; also that 

 the difference in absorption of creosote oil in different: pieces is 

 notable, and that there is marked evaporation of the oil upon ex- 

 posure. In the experiment over half of the oil seemed to disappear 

 within nine months. 



Tests to determine the mechanical properties of different species of 

 hickory were also completed. A partial summary of results has been 

 incorporated in a report on the commercial h'ckorics and is being 

 published. On the whole, pignut, or black hickory, gave the best 

 results in the tests. It is closely followed by shagbark, which, in 

 addition to its valuable wood, furnishes an important edible nut. 

 Mockernut has nothing to recommend it over pignut. Pecan hick- 

 ories, though of faster growth than true hickories, have inferior wood. 

 The tests show that the prejudice which exists against the heartwood 

 of hickory is unfounded. In old trees the best wood ma}^ be in the 

 heart, while in young trees the best w^ood is likely to be in the sap. 



Material progress was made in working up the tests to determine the 

 effect of difl'erent methods of drying on the strength of timber, which 

 have been under way for two j^ears. 



