5.) A familiar instance of this action is afforded by a flexible walking-stick.

If downward pressure is exerted with the hand on the upper end of the stick placed vertically on the floor, it will be noted that a definite amount of force must be applied in each instance before decided flexure takes place.

After this point is reached a very slight increase of pressure very largely increases the deflection, thus obtaining so great a leverage about the middle section as to cause rupture.
[Illustration: FIG.

5 .-- Testing a buggy spoke in endwise compression, illustrating the failure by sidewise bending of a long column fixed only at the lower end.

_Photo by U.S.Forest Service_] The lateral bending of a column produces a combination of bending with compressive stress over the section, the compressive stress being maximum at the section of greatest deflection on the concave side.