This stress must be taken into consideration in the design of timber structures.

It is maximum at the neutral plane and decreases to zero at the outer elements of the section.

The shorter the span of a beam in proportion to its height, the greater is the liability of failure in horizontal shear before the ultimate strength of the beam is reached.
_Beams_ There are three common forms of beams, as follows: (1) ~Simple beam~--a bar resting upon two supports, one near each end.

(See Fig.

16, No.