The determination should be made upon each volume separately, and the average for the entire cross section obtained from these results.
At the conclusion of the test the failure, as it appears on each surface, is traced on the sketches, with the failures numbered in the order of their occurrence.

If the beam is subsequently cut up and used for other tests an additional sketch may be desirable to show the location of each piece.
_Adjusting specimen in machine_: The beam is placed in the machine with the side marked _a_ on top, and with the ends projecting equally beyond the supports.

In order to prevent crushing of the fibre at the points where the stress is applied it is necessary to use bearing blocks of maple or other hard wood with a convex surface in contact with the beam.

Roller bearings should be placed between the bearing blocks and the knife edges of the crosshead to allow for the shortening due to flexure.

(See Fig.