302 TIMBER 



do with the testing of this material know that the smaller 

 the specimen the higher the result. Small sample pieces of 

 timher are obtained in more perfect condition, have fewer 

 flaws and knots, often no knots at all, while these imperfec- 

 tions cannot be avoided in the case of timber of the sizes 

 used in constructional work ; hence in most cases it has 

 been assumed, during recent years, that the results obtained 

 from small test specimens should, when put into practice, 

 be reduced by 50 per cent, or even more. 



It is a curious thing that in the case of timber, although 

 one of the oldest constructive materials, and the one of 

 which more is used than any other, we have been content 

 to depend upon what are more or less doubtful tests, whilst 

 in the case of steel, a material only a few years in use, we 

 can rely upon accurate tests. It is not satisfactory, con- 

 sidering the number of powerful testing appliances now in 

 use, that the tests made on timber of large scantling are so 

 very meagre. Although the movement in the direction of 

 remedying this state of things is slow, it is gradually 

 coming to be considered necessary that tests made on 

 timber, to be of any value, should be upon pieces such as 

 are used in actual work, and not upon small or specially 

 prepared specimens. The late Professor J. B. Johnson 

 initiated a valuable series of tests on timber for the United 

 States Government. Professor Lanza also carried out a 

 great number of useful tests on large-sized timber, chiefly 

 white and yellow pine (pitch pine) and spruce, at the 

 Watertown Arsenal, and the Massachusetts Institute of 

 Technology, United States, which have thrown a good deal 

 of practical light on the subject, and the United States 

 Government are continuing these tests. Quite recently the 

 Government of Western Australia has, under the direction 

 of Mr. G. A. Julius, B.Sc., M.E., tested thousands of 

 different-sized pieces of the hardwoods of this arid other 



