378 FORESTRY INVESTIGATIONS U. S. DEPARTMENT OF AGRICULTURE. 



development of the investigation and its methods was not published until 1892, in Bulletin G, in 

 which Mr. Fernow described the aims, objects, and methods at length. 

 In the report for 1800 the following language is used: 



TIMBER TESTIS 



While the use of wood pulp and other substitutes may displace in many ways the use of w,ood in its natural 

 state, there will always be desirable qualities inherent in the latter that make its use indispensable. Hence the 

 desirability of knowing the qualities of our timbers and, if possible, of knowing the conditions under which, the 

 wood crop will develop the desirable qualities. 



Much work and u&eful work is done in the world by the rule of thumb. All such work is not reliable and 

 certainly not economical. With the need of greater economy in production, the need of more accurate measuring 

 arises, and with that the need of more specific knowledge of the mateiials to be measured. 



Wood is one of the materials which has been measured by the rule of thumb longer than others. Iron and 

 other metals used in the arts have their properties much more accurately determined than wood material. Especially 

 in the United States, when we speak of quality of our timbers, it can only be in general terms; we lack definite data. 

 One difficulty in determining reliably the qualities of our timbers lies in the fact that living things are rarely 

 j) ret isely alike. Every tree differs from every other tree, and the material taken from the one has a different value 

 from that taken from the other of the same species. Yet every tree has some characteristics in common with, all 

 those grown under similar conditions. But even these common properties differ in degree in different individuals. 

 Individual variation tends to obscure relationship. 



The factors which determine the quality of timbers are found directly in tbo structure of the wood, and it is 

 possible from a mere ocular examination to judge to some extent what qualities may be expected from a given piece 

 of timber, although even in this direction our knowledge is very incomplete, and but few definite relations between 

 structure and quality, or between physical and mechanical properties, are established. We know that the width of 

 the annual rings, their even growth, the closeness of grain, the length, number, thickness, and distribution of the 

 various cell elements, the weight, and many other physical appearances and properties of the wood influence its 

 quality, yet the exact relation of these is but little studied. Conjectures more or less plausible, suppositions, and a 

 few practical experiences preponderate over positive knowledge and results of experiments. Again we know, in a 

 general way, that structure and composition of the wood must depend upon the conditions of soil, climate, and 

 surroundings under which the tree is grown, but there are only few definite relations established. We are largely 

 ignorant as to the nature of our wood crop, and still more so as to the conditions necessary to produce desirable 

 qualities, and since forestry is not so much concerned in producing trees as in producing quality in trees, to acquire 

 or at least enlaige this knowledge must be one of the first and most desirable undertakings in which this Division 

 can engage. 



Accordingly a comprehensive plan has been put into operation to study systematically our more important 

 timber trees. 



It will at once be understood that as long as the qualities are to be referied to the conditions under which the 

 tree is grown, the collection of the study material must be made with the greatest care, and the material must be 

 accompanied with an exhaustive description of these conditions. Since, further, so much individual variation seems 

 to exist in trees grown under seemingly the same conditions, a large number must be studied in order to arrive at 

 reliable average values. For the present it has been decided to study the pines, especially the white pine and the 

 three Southern lumber pines. 



In selecting localities for collecting specimens, a distinction is made between station and site. 

 By station is understood a section of country (or any places within that section) which is characterized in a 

 general way by similar climatic conditions and geological formation. Station, then, refers mainly to the general 

 geographical situation. Site refers to the local conditions and surroundings within the station, such as difference of 

 elevation, of exposure, of physical properties and depth of the soil, nature of subsoil, and forest conditions, such as 

 mixed or pure growth, open or close stand, etc. 



The selection of characteristic sites in each station requires considerable judgment. 



On each site five full-grown trees are to be taken, four of which are to be representative average trees; the 

 fifth or "check'' tree, however, should be the best developed tree that can be found on the site. Some additional 

 test trees will be taken from the open and also a few younger trees. The trees are cut into varying lengths, and from 

 each log a disk of 6-inch height is secured, after having marked the north and south sides and noted the position of 

 the log in the tree. 



The disks are sent for examination of the physical and physiological features to the Michigan University, while 

 the logs, and latei on special parts of the disks are to be sent to the test laboratory of the Washington University 

 of St. Louis. Here, for the first time, a systematic series of beam tests will be made and compared with the tests on 

 the usual small laboratory test pieces. Such tests with full-length beams in comparison with tests on small speci- 

 mens promise important practical results, for a few tests have lately developed that large timbers seem to have but 

 little more than one-half the strength they were credited with by standard authorities, who relied upon the tests on 

 small specimens. 



From the "check" tree mentioned before only clear timber is to be chosen, in order to ascertain the possibilities 

 of the species and also to establish, if possible, a relation between such clear timber and that W$d * n general 

 practice, whore elements of weakness are introduced by knots and other blemishes. 



