It is the general purpose of the work here outlined to provide:

(a) Reliable data for comparing the mechanical properties of various species;

(b) Data for the establishment of correct strength functions or working stresses;

(c) Data upon which may be based analyses of the influence on the mechanical properties of such factors as:

Locality;

Distance of timber from the pith of the tree;

Height of timber in the tree;

Change from the green to the air-dried condition, etc.

The mechanical properties which will be considered and the principal tests used to determine them are as follows:

Strength and stiffness -

Static bending;

Compression parallel to grain;

Compression perpendicular to grain;

Shear.

Toughness -

Impact bending;

Static bending;

Work to maximum load and total work.

Cleavability -

Cleavage test.

Hardness -

Modification of Janka ball test for surface hardness.