302 TIMBEES AND THEIR USES 



strength, in end compression falls to an 

 extent of 2-9 per cent ; in the case of 

 Karri and in that of Tooart, 6-1 per cent 

 (these being the two limits) ; and the 

 failure in 60 per cent of the tests was by 

 ' side flexure.' 



The strength is quickly reduced as the 

 ' column ratio ' is increased, and at a 

 value of 36/1, which was the limit tested,', 

 the reduction in strength, below that, at 

 a 12/1 ratio, varied between 39 per cent 

 (Karri) and 47 per cent (Wandoo). 



It was found that the same percentages 

 of reduction were closely followed at 

 higher moisture values ; hence, from the 

 data given, the strength of any column 

 at any ' moisture percentage ' can readily 

 be computed. 

 3. In all cases when the failure occurred in 

 direct crushing, the fracture was of a 

 sliding nature, and this ' sliding ' invari- 

 ably took flace in the direction of the 

 annual rings. 



In turned specimens, and in rect- 

 angular specimens, wherever sliding oc- 

 curred in a direction parallel to one of 

 the sides of the specimen, the angle of 

 sliding was always close to 45°. 



In nearly all other cases the angle of 



