After testing, the manner of failure is shown for all four sides, and the various parts of the failure are numbered in the order of their occurrence.
_Adjusting specimen in machine_: The compressometer collars are adjusted, the distance between them being 20 inches for the posts and 6 inches for the blocks.

If the two ends of the blocks are not exactly parallel a ball-and-socket block can be placed between the upper end of the specimen and the movable head of the machine to overcome the irregularity.

If the blocks are true they can simply be stood on end upon the platform and the movable head allowed to press directly upon the upper end.
_Measuring the deformation_: The deformation is measured by a compressometer.

(See Fig.

33.) The latter registers to 0.001 inch.