54 



TIMBER AND TIMBER TREES. [CHAP. 



heart-shake are African Oak, or Teak, as it is sometimes 

 called ; Sabicu ; Cuba Mahogany ; and English Elm ; 

 while Indian Teak* and Australian Tewart have it in 

 a very objectionable form. These species are among 

 the hard and strong woods used for architectural pur- 

 poses in this country, an^ by cabinet-makers for the 

 manufacture of furniture, and for other domestic uses. 



As regards the white or softer woods, it is generally 

 very small in the Dantzic, but extensive and open in 

 Riga and Swedish Fir. In the Pines, the Canadian Red 

 is perhaps the closest and least of all affected by it, the 

 Canadian Yellow coming next in order ; but in the 

 Pitch Pine of the Southern States of North America it 

 is often present in a more enlarged form, and the centre, 

 or pith, of this species cannot well be approached if thin 

 boards are required to be cut from it. 



This defect, as before mentioned, affects and pervades 

 more or less nearly every description of timber ; it is 

 common to all the dicotyledonous trees as well as 

 Conifers, and neither soil nor situation appears to have 

 anything to do with its origin. It must be accepted as 

 an indication of incipient decay consequent on old age ; 

 the gradual loss of solid substance in the oldest layers 

 of wood causing them to shrink more than the specifi- 

 cally heavier younger ones. Our study should be to so 

 utilise the trees possessing it in its most extensive and 

 objectionable form, as to employ them for purposes 

 which entail doing as little as possible to them if we 

 wish to convert the logs profitably. The heart-shake 

 is so very insignificant in some timber, that many 



* In India, the forest officers have atlrilrateti-the-Jifiar^jhake in Teak to 

 the ringing, or barldng, the trees', to kill^theni before they are felled. It has, 

 however, been proved that, where this has not been done, and the trees were 

 felled green, heart-shake was found in them. 



