The Montgomery advertiser., 1906-01-13
Matinee at Bijou Today 8 D. m. The Millionaire Detective,
STRENGTH TESTS OF T,mnnR.
The Testing Machine in a south Car
 oIina MiIi.


 Washington Letter
 The Forest Service has been con duct. ing extensive tests at the E. P. Burton Lar.ber Compa 1y's sawmill, near Cha"ieston s. C, 70 deterr.ine the strength of iobloily psne Tnc timber, wE.ca io known ca the ioca! market s.s North Cstrolina- pi.ic. forms the graat- CT part os the lumber cut at this raiil The loblaEy pine furnishes a useful eor5tructicJ tirlber of moderate strength, Is of very rapid growth and reproduces readily. For these reasons II will remain one of the most import ant timber trees of the South. Correct data on it's strength will be of perma- nent value.
 It IS found much more convenient to take the testing machine to the mill instead of bringing the large sticks of timber to the laboratory from the mill. The conditions to which the stick of timber is subjected after being cut in the forest determine to some degree how it will act when put in use where 1t will have to carry a load or bear A strain. And so 1t sometimes becomes an important matter to know tke his- tory of the sticks tested. The Iogs from which it is desired to cut the test pieces can be selected in the forest, marked, and subsequently, identified at the log pond. A concise history of each log Is kept, showing the location of the tree in the forest the kind of soil in which it grew, the time of cut ting. and the length of time the log lies in the water. On arriving at the mill the log is sawed in any way de- sired. and can then either be tested shortly after coming from the saw or laid aside for the purpose of air drying Ir1I 1,-4~f k.e-s step of importance in the life of the log after cutting is thus known. and meny peculiarities which arise in the behavior of sticks when tested can be explained
 The testing machine is set uE in the mill and driven by the mill machinery. The sawyer in. the mill saws exactly the kind of sticks desired. and the pieces intended for test are sent direct ly to the testing machine
 The plan of work at Charleston in- cluded investigations to determine the effect of knots on the strength of tim Der; the relative strength of air-dried and kiln-dried timber: the effect of rate of growth upon the strength; the influence of the relative strength of sap and heart wood and the influence on the strength of the method of saw ing.
 Judging from the inquiries received in the Service, widespread interest is manifested in this line of work, and without doubt many questions yet un- decided will be definitely answered on the completion of the tests. The spec ifications. for instance, under which en- gineers and architects receive joists are. very imperfect because no one knows the exact degree of weakening which arises from the presence of knots of various sizes and kinds in the joists. Again, there is a common prejudice against sapwood on account of it's sup posed weakness. whereas tho tests will show that in cases where durability is not an important factor the sapwood is as strong as the heartwood.
 The strength of wood is prejudiced by the presence of knot. depending upont the position of the knot, on it's condition, and on its size with refer encc to the crcss-section of the stick. When a knot is firm and closely knit to the surrounding wood, 1t is much less harmful than when it is loose or shaky.
 In the case of a beam loaded in the center, if a knot occurs in the lower portion of the beam, close enough to turn the grain off, 1t causes rupture. A comparatively large knot placed far enough from the edge jf the stick to allow the fiber to be continuous when passing Is less weakening than a snAall- CT knot located SC as to turn the grain off from the edge when passing it.
 Knots in the top of 6 stick are less weakening than those in the bottom. Indeed. it is the common practice of users of timber blocking for temporary purposes, when a wooden beam has failed at the bottom. to turn it upside down and use 1t again.