440 HOW FAILURE UNDER STRESS OCCURS IN TIMBER. 
Pruate VII. 
Fig. 29. Oak. A tangential section from the compressed side of a beam, x 176 diams., showing crumpling 
of the tissues. The direction of the induced compression C is shown by the arrow-heads. 
Fig. 30. Oak. A tangential section from the fractured lower portion of a beam, x 176 diams. 
Fig. 31. Oak. A transverse section of log, x { n.s., which has been fractured by longitudinal com- 
pression. The slip is essentially a tangential one. Note.—This specimen contains the centre of tree. 
Fig. 32. Oak. A set of beams which have been laid on their tangential face and fractured by cross- 
breaking. The radial faces are exhibited x4n.s. Mote.—The line of shear is always nearer the tension 
side. Ratios of ; less than 4. 
Prate VIII. 
Fig. 33. Oak. Seven specimens fractured by longitudinal compression, x 4 n.s. K-—=narrow dimension, 
and is radial. Local buckling takes place until /=8h, and is tangential. Above this it is a compound of 
bending and local crumpling in oblique plane. 
Fig. 34. Oak. Seven specimens fractured by longitudinal compression, x 4 n.s. K =narrow dimension, 
and is tangential. Local buckling occurs until 7=6/ and is tangential. Above this it is a compound of 
bending and buckling in a vertical plane. 
