3 .-- Side view of failures in compression across the grain, showing crushing of blocks under bearing plate.

Specimen at right shows splitting at ends.] [Illustration: FIG.

4 .-- End view of failures in compression across the grain, showing splitting of the ends of the test specimens.] When wood is used for columns, props, posts, and spokes, the weight of the load tends to shorten the material endwise.

This is ~endwise compression~, or compression parallel to the grain.
In the case of long columns, that is, pieces in which the length is very great compared with their diameter, the failure is by sidewise bending or flexure, instead of by crushing or splitting.

(See Fig.