6 4 8 



Yearbook^ of Agriculture 1949 



assumption that, if you know what 

 wood is and why it behaves as it does, 

 you have the information you need to 

 solve your practical problems. 



The more recent accomplishments 

 of the Laboratory, such as transform- 

 ing cull trees, sawdust, and other wood 

 residues into sugar-rich stock feeds, or 

 building serviceable house walls from 

 sandwiches of veneer and paper with- 

 out framing members, may appear 

 most striking. Those and other equally 

 solid applications of its work, however, 

 result from its past research, which not 

 only supplies a basis for new concepts 

 that help make such accomplishments 

 possible, but supplies means of con- 

 stantly improving established wood 

 uses. 



The applications of this work start in 

 the forest, where trees are cut into logs. 

 Except for the variations in diameter, 

 taper, and crook, all logs look much 

 alike. Yet from early lumbering days 

 it has been important that timber 

 owners and mill operators be able to 

 recognize from the outward appear- 

 ance of logs the quality as well as the 

 quantity of lumber that can be cut 

 from them. A system of grading logs 

 according to recognizable characteris- 

 tics has become increasingly necessary 

 so that buyers and sellers of logs, par- 

 ticularly from farm woodlands, can 

 have a basis for definite and equitable 

 dealings. Applying knowledge gathered 

 in the woods, sawmills, veneer mills, 

 and elsewhere, the Laboratory has de- 

 veloped a system of grading hardwood 

 logs that is now followed by the Forest 

 Service in making timber inventories 

 and that is gradually coming into use 

 in the commercial buying and selling of 

 logs. When once it is firmly established, 

 this grading system promises substan- 

 tial aid in forest management. 



Kiln-dried lumber has become a 

 standard commodity throughout the 

 United States. To assure that such 

 lumber would be dried to the moisture 

 content most suitable for the use to 

 which it is to be put, the Laboratory 

 developed schedules of temperature 

 and relative humidity for drying lum- 



ber of various thicknesses rapidly and 

 with a minimum of damage. It has 

 made available such schedules for al- 

 most all native American woods and 

 for some foreign woods. As a result, 

 although there may be local or tem- 

 porary lapses from good kiln-drying 

 standards, the general level of excel- 

 lence of wood seasoning in the United 

 States is not equaled elsewhere in the 

 world. The Laboratory began its work 

 on improved kiln-drying methods in 

 about 191 3 by working out and making 

 known the physical laws governing the 

 rapid seasoning of wood. Its efforts 

 continue toward development of still 

 better technical control of the drying 

 processes. 



Most of the 5,000 or more dry kilns 

 in use in this country have been de- 

 signed by their manufacturers upon 

 the principles of the original internal- 

 fan kiln pioneered at the Laboratory. 

 Those kilns, including all of the new 

 and most of the remodeled ones, have 

 given satisfaction of a high order. 



The man who now buys lumber at 

 a lumber yard for repairs, alterations, 

 or new construction usually gets a 

 product of standard dimensions and 

 pattern that, within reasonable toler- 

 ances, will be the same as he bought 

 for a like purpose at a previous time. 

 This was not always true, because the 

 lumber from different mills and areas 

 varied widely in dimensions and pat- 

 tern until some 25 years ago. About 

 that time the Forest Products Labora- 

 tory played an important role, with the 

 United States Department of Com- 

 merce, in standardizing lumber dimen- 

 sions by assisting the manufacturers, 

 distributors, and consumers of lumber 

 in setting up American standards to 

 replace the local and regional stand- 

 ards previously existing. Today, as a 

 result, house flooring, siding, and other 

 lumber can be bought in the same 

 sizes whether made in New England, 

 the Lake States, the South, or the West. 



The bountiful supply of woods suit- 

 able for structural purposes with which 

 the United States has been blessed has 

 been given added value through more 



