| |---------------------------------+-----------------------------------------+-------------------------------------------------------------------------| Ratio | | | Extreme | Modulus of | Parallel to | Longitudinal | Perpendicular | Parallel to | For | Formulæ for | of | | | fibre | elasticity | the grain | shear in | to the grain | the grain | columns | working stress in | length | | KIND OF | stress | | | beams | | | under 15 | long columns over | of | | TIMBER |--------------------+------------+--------------------+--------------------+--------------------+--------------------| diameters | 15 diameters | stringer | | | Average | Working | | Average | Working | Elastic | Working | Elastic | Working | Average | Working | working | | to | | | ultimate | stress | Average | ultimate | stress | limit | stress | limit | stress | ultimate | stress | stress | | depth | |-----------------+----------+---------+------------+----------+---------+----------+---------+----------+---------+----------+---------+-----------+-------------------+----------| | Douglas fir | 6100 | 1200 | 1,510,000 | 690 | 170 | 270 | 110 | 630 | 310 | 3600 | 1200 | 900 | 1200(1-_l_/60_d_) | 10 | |-----------------+----------+---------+------------+----------+---------+----------+---------+----------+---------+----------+---------+-----------+-------------------+----------| | Longleaf pine | 6500 | 1300 | 1,610,000 | 720 | 180 | 300 | 120 | 520 | 260 | 3800 | 1300 | 980 | 1300(1-_l_/60_d_) | 10 | |-----------------+----------+---------+------------+----------+---------+----------+---------+----------+---------+----------+---------+-----------+-------------------+----------| | Shortleaf pine | 5600 | 1100 | 1,480,000 | 710 | 170 | 330 | 130 | 340 | 170 | 3400 | 1100 | 830 | 1100(1-_l_/60_d_) | 10 | |-----------------+----------+---------+------------+----------+---------+----------+---------+----------+---------+----------+---------+-----------+-------------------+----------| | White pine | 4400 | 900 | 1,130,000 | 400 | 100 | 180 | 70 | 290 | 150 | 3000 | 1000 | 750 | 1000(1-_l_/60_d_) | 10 | |-----------------+----------+---------+------------+----------+---------+----------+---------+----------+---------+----------+---------+-----------+-------------------+----------|