TIMBER TESTING 303 



sliding lay between 40° and 45° where 

 measured directly in the direction of 

 movement. 



Where the specimens failed as ' long 

 columns,' i.e. by lateral flexure, in the 

 majority of cases .failure occurred in the 

 direction of the annual rings, rather than 

 radially ; but in many cases this was not 

 so, apparently due to local inequaUties 

 in the specimens."* 



The transverse or bending stress of wood may 

 be tested in a number of ways, and there are 

 strong advocates of each method. The methods 

 of loading the beams for testing are usually 

 either central or third point. The reader who 

 desires further information on the subject is 

 referred to Professor S. J. Record's standard 

 work on " The Mechanical Properties of Wood." 

 As the maj ority of tests of importance in America, 

 Canada and AustraUa have been performed with 

 central loading, we shall confine our remarks to 

 that method. 



The beam for test is cut to a- definite size, 

 which may be such as to suit the proportions 

 of the testing machine and the convenience of 

 the operator. It is, however, essential that the 



* " The Physical Characteristics of the Hardwoods of 

 Western Australia." 



