Dept.
For., N.S.W., Sydney, 1911, pp.

88-95.] The wood to be tested is cut into blocks 3" X 3" X 1', and these are weighed to the nearest grain just before placing in the apparatus.

Steam from the boiler at a pressure of about 43 pounds per square inch is ejected from a nozzle in such a way that particles of fine quartz sand are caught up and thrown violently against the block which is being rotated.

Only superheated steam strikes the block, thus leaving the wood dry.
The test is continued for two minutes, after which the specimen is removed and immediately weighed.
By comparison with the original weight the loss from abrasion is determined, and by comparison with a certain wood chosen as a standard, a coefficient of wear-resistance can be obtained.

The amount of wear will vary more or less according to the surface exposed, and in these tests quarter-sawed material was used with the edge grain to the blast.
_Indentation_: The tool used for this test consists of a punch with a hemispherical end or steel ball having a diameter of 0.444 inch, giving a surface area of one-fourth square inch.