STAR- AND HEART-SHAKE 



57 



tree is newly felled as to be scarcely perceptible. In such a case 

 they generally widen during seasoning, from the more rapid drying 

 of the outer layers, their sides becoming darker in colour than the 

 rest of the wood. In other instances the clefts may have extended 

 to the circumference of the stem, in which case they may have been 

 so overgrown by new wood as to form a longitudinal rib down the 

 exterior of the bark, a sure sign of the defect to the experienced 

 timber surveyor. Such extreme cases at least seem to be always 

 the result of frost or sun, the latter being specially frequent in the 

 case of smooth thin-barked species, such as Beech and Hornbeam, 

 in which hues of the cortex are killed by sun-bum. 



Fig. 38.— star-shake. 



Heart-shake. — ^More common than either cup-shake or star- 

 shake is heart-shahe, one or two clefts crossing the central rings of 

 the stem and widening towards the centre (Fig. 39). 



This may occur in almost every kind of timber, whether coni- 

 ferous or broad-leaved, and seems to be quite independent of soil 

 or situation. Among species least afected by it Mr. Laslett^ 

 mentions the so-called African Oak or Teak {Oldfieldia africdna), 

 Sabicu, Spanish Mahogany, Common Elm, Dantzic Fir or Redwood 

 {Pinus sylvestris), Canadian Red Pine {Finns resinosa), and, some- 

 what less free from it, Canadian Yellow Pine (Pinus Strobus) ; 

 whilst as exceptionally Hable to the defect he mentions the true 

 Indian Teak [Tectona grdndis), the Austrahan Tewart (Uucalyptus 

 gomphocephala), the Riga and Swedish varieties of Pinus sylvestris, 

 and P. austrdlis, the Pitch Pine of the southern United States. 



^ Timber and TimbeT4rees, cd. ii., p. 54 



