THE FOREST PRODUCTS LABORATORY

GEORGE M. HUNT.

The Forest Products Laboratory, which is maintained in Madison, Wis., as a unit of the United States Department of Agriculture, conducts research to help conserve the Nation's timber supply and make it serve more satisfactorily the needs of the people for wood products of all kinds.

For nearly 40 years the Laboratory has been doing this work. Today virtually every use of wood known to man is directly affected by it.

Hardly a day passes without visits from representatives of forest-products industries seeking information about wood: What is the correct temperature and relative humidity to use in drying magnolia for venetian blinds? Can the new resin glues be used in piano production? What is the best type of wood sheathing for house construction? What grade of plywood is best for outdoor use? How do you bag mold a plywood boat? What will happen if I apply white paint to my red barn? Am I entitled to the free use of the Laboratory's patents on the semichemical process of paper making? How does the Laboratory make molasses from wood? And many other questions about the thousands of uses to which wood is put.

Each day brings fresh batches of letters, telegrams, and telephone calls from every State from great corporations and Government agencies, home owners, farmers, and operators of small sawmills, woodworking establishments, and factories. The questions range from the complex problems of aerodynamic design to paint peeling off a house or lumber warping in the seasoning pile. But fundamentally they are alike in that they generally involve the basic problem of wood use an understanding of its fundamental properties, such as strength, wood-moisture relations, and the physical and chemical structure of this common but highly complex substance. It is toward a better understanding of those fundamental properties that the Laboratory has aimed its scientific inquiries, on the 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 transforming cull trees, sawdust, and other wood residues into sugar-rich stock feeds, or building serviceable house walls from sandwiches of veneer and paper without 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 constantly 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 appearance 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 characteristics has become increasingly necessary so that buyers and sellers of logs, particularly 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 developed 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 substantial 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 lumber of various thicknesses rapidly and with a minimum of damage. It has made available such schedules for almost all native American woods and for some foreign woods. As a result, although there may be local or temporary lapses from good kiln-drying standards, the general level of excellence 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 1913 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 designed 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 tolerances, 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 pattern until some 25 years ago. About that time the Forest Products Laboratory played an important role, with the United States Department of Commerce, in standardizing lumber dimensions by assisting the manufacturers, distributors, and consumers of lumber in setting up American standards to replace the local and regional standards 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 suitable for structural purposes with which the United States has been blessed has been given added value through more intelligent use and by reliable data on the growth, structure, and strength properties of these species. More than a million tests have provided data on which to base sound working stresses and establish structural grades for use in design and for inclusion in building codes. The test methods developed at the Laboratory were recognized in 1927 by the American Society for Testing Materials and have been adopted in many foreign countries.

More than 175 native woods, as well as some foreign species, have been tested for strength. Companion data needed by design engineers have been obtained on such types of fastenings as nails, screws, and connectors, and studies have been made to determine the effect of loading conditions, defects, and moisture on strength. New constructions, such as plywood and sandwich materials, have been investigated and the strength of these complex materials determined both by actual tests and by means of mathematical analyses that short-cut laborious and time-consuming tests of individual specimens. This information has been depended on widely by the wood-using industries in the selection of material and species for specific purposes, such as poles, structural timbers, aircraft, boxes, boats, and housing.

The development of Federal specifications for wood and fiberboard boxes has been almost entirely a responsibility of the Laboratory for the past 30 years. Although these specifications were designed for Government use, they have been widely adopted as the basis for improved commercial containers that have greatly reduced shipping costs. It has been estimated that the research on containers has effected annual peacetime savings of about 40 million dollars through reduced damage to merchandise, use of thinner lumber, and containers of lower weight and less volume.