. Bulletin. Forests and forestry -- United States. INFLUENCE OF MOISTURE ON STUENQTII. 19 INFLUENCE OF MOISTURE. This influence is among the most important, hence all tests have been made with due regard to moisture contents. Seasoned wood is stronger than green and moist wood; the ditlereuce between green and seasoned wood may amount to 50 and even 100 per cent. The influence of seasoning consists in (1) bringing by means of shrinkage about 10 per cent more fibers into tlie same square inch of cross section than are contained in the wet wood; (li) shrinking the cell wall itself by about 50 pe
. Bulletin. Forests and forestry -- United States. INFLUENCE OF MOISTURE ON STUENQTII. 19 INFLUENCE OF MOISTURE. This influence is among the most important, hence all tests have been made with due regard to moisture contents. Seasoned wood is stronger than green and moist wood; the ditlereuce between green and seasoned wood may amount to 50 and even 100 per cent. The influence of seasoning consists in (1) bringing by means of shrinkage about 10 per cent more fibers into tlie same square inch of cross section than are contained in the wet wood; (li) shrinking the cell wall itself by about 50 per cent of its cross section and thus hardening it, just as a cowskiu becomes thinner and harder by drying. In the following tables and diagram this is fully illustrated; the values presented in these tables and diagrams are based on large numbers of tests and are fairly safe for ordinary use. They still require further revision, since the relations to density, etc., have had to be neglected in this study. Jnjhieiice of iiinistiire on sirenijth. Dending strength: (Ireon ]l:ilt' ilry Yard dry Kcjoni dry Cruehing endwise: Green , Half dry Yard dry Koorii dry Mean ut' both bending and enj«hing strength: Green Half dry Yard dry Boom dry Per cent of mois- ture. 3^+ 20 15 10 33 + 20 15 10 33+ 20 15 10 Average of all valid tests. c-"-- "CI 8,450 10. U50 11, 950 15, 30U 5,000 7,850 9, 200 7,060 8,900 10, 900 14, 000 4,450 5,450 6, 850 ',), 200 Lob- lolly. 7,370 8, 050 10,100 12, 400 4,170 5,350 6,500 8,650 Short- leaf. 6,900 8,170 9,230 11, 000 4,160 5,100 5,900 7,000 Kelative values. Cuban. 100 118 142 181 100 132 157 184 100 125 149 182 Long- leaf. 100 116 142 182 100 122 1,54 206 100 Hi) 148 194 Lob- lolly. 100 117 138 168 156 200 100 122 147 187 Short- leaf. 100 118 134 160 100 122 142 168 100 120 138 164 Aver- age. 100 117 139 173 100 126 152 191 100 122 146 182. 4 S & 7 S S Fia. 3—Uia^'ram showing variation of compression strength with uioiaturo. It will be
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