,280 | Hickory | 7,285 |
| Beech | 5,223 | Locust | 7,176 |
| Birch | 5,595 | Maple | 6,355 |
| Cedar (white) | 1,372 | Oak | 4,425 |
| Cedar (white) | 1,519 | Oak (live) | 8,480 |
| Cedar (Central Amer.) | 3,410 | Pine (white) | 2,480 |
| Cherry | 2,945 | Pine (northern yellow) | 4,340 |
| Chestnut | 1,536 | Pine (southernyellow) | 5,735 |
| Dogwood | 6,510 | Pine (very resinous yellow) | 5,053 |
| Ebony | 7,750 | Poplar | 4,418 |
| Gum | 5,890 | Spruce | 3,255 |
| Hemlock | 2,750 | Walnut (black) | 4,728 |
| Hickory | 6,045 | Walnut (common) | 2,830 |
|---------------------------------------------------------------------------|
| NOTE.--Two specimens of each were tested. All were fairly seasoned and |
| without defects. The piece sheared off was 5/8 in. The single circular |
| area of each pin was 0.322 sq. in. |
|---------------------------------------------------------------------------|

TRANSVERSE OR BENDING STRENGTH: BEAMS

When external forces acting in the same plane are applied at
right angles to the axis of a bar so as to cause it to bend,
they occasion a shortening of the longitudinal fibres on the
concave side and an elongation of those on the convex side.
Within the elastic limit the relative stretching and contraction
of the fibres is directly[9] proportional to their distances
from a plane intermediate between them--the ~neutral plane~.
(N_{1} P in Fig. 15.) Thus the fibres half-way between the
neutral plane and the outer surface experience only half as much
shortening or elongation as the outermost or extreme fibres.
Similarly for other distances. The elements along the neutral
plane experience no tension or compression in an axial
direction. The line of intersection of this plane and the plane
of section is known as the ~neutral axis~ (N A in Fig. 15) of
the section.

[Footnote 9: While in reality this relationship does not exactly
hold, the formulae for beams are based on its assumption.]

[Illustration: FIG. 15.--Diagram of a simp