The strength of a column also depends to a considerable extent upon whether the ends are free to turn or are fixed.
[Illustration: FIG.

6 .-- Unequal distribution of stress in a long column due to lateral bending.] |-------------------------------------------------------| | TABLE IV | |-------------------------------------------------------| | RESULTS OF COMPRESSION TESTS ACROSS THE GRAIN ON | | 51 WOODS IN GREEN CONDITION, AND COMPARISON WITH | | WHITE OAK | | (U.S.Forest Service) | |-------------------------------------------------------| | | Fibre stress | Fiber stress | | COMMON NAME | at elastic | in per cent | | OF SPECIES | limit | of white oak, | | | perpendicular | or 853 pounds | | | to grain | per sq.in.

| |-----------------------+---------------+---------------| | | Lbs.

per | | | | sq.

inch | Per cent | | | | | | Osage orange | 2,260 | 265.0 | | Honey locust | 1,684 | 197.5 | | Black locust | 1,426 | 167.2 | | Post oak | 1,148 | 134.6 | | Pignut hickory | 1,142 | 133.9 | | Water hickory | 1,088 | 127.5 | | Shagbark hickory | 1,070 | 125.5 | | Mockernut hickory | 1,012 | 118.6 | | Big shellbark hickory | 997 | 116.9 | | Bitternut hickory | 986 | 115.7 | | Nutmeg hickory | 938 | 110.0 | | Yellow oak | 857 | 100.5 | | White oak | 853 | 100.0 | | Bur oak | 836 | 98.0 | | White ash | 828 | 97.1 | | Red oak | 778 | 91.2 | | Sugar maple | 742 | 87.0 | | Rock elm | 696 | 81.6 | | Beech | 607 | 71.2 | | Slippery elm | 599 | 70.2 | | Redwood | 578 | 67.8 | | Bald cypress | 548 | 64.3 | | Red maple | 531 | 62.3 | | Hackberry | 525 | 61.6 | | Incense cedar | 518 | 60.8 | | Hemlock | 497 | 58.3 | | Longleaf pine | 491 | 57.6 | | Tamarack | 480 | 56.3 | | Silver maple | 456 | 53.5 | | Yellow birch | 454 | 53.2 | | Tupelo | 451 | 52.9 | | Black cherry | 444 | 52.1 | | Sycamore | 433 | 50.8 | | Douglas fir | 427 | 50.1 | | Cucumber tree | 408 | 47.8 | | Shortleaf pine | 400 | 46.9 | | Red pine | 358 | 42.0 | | Sugar pine | 353 | 41.1 | | White elm | 351 | 41.2 | | Western yellow pine | 348 | 40.8 | | Lodgepole pine | 348 | 40.8 | | Red spruce | 345 | 40.5 | | White pine | 314 | 36.8 | | Engelman spruce | 290 | 34.0 | | Arborvitae | 288 | 33.8 | | Largetooth aspen | 269 | 31.5 | | White spruce | 262 | 30.7 | | Butternut | 258 | 30.3 | | Buckeye (yellow) | 210 | 24.6 | | Basswood | 209 | 24.5 | | Black willow | 193 | 22.6 | |-------------------------------------------------------| The complexity of the computations depends upon the way in which the stress is applied and the manner in which the stick bends.
Ordinarily where the length of the test specimen is not greater than four diameters and the ends are squarely faced (see Fig.
7), the force acts uniformly over each square inch of area and the crushing strength is equal to the maximum load (P) divided { P } by the area of the cross-section (A).