286 TIMBERS AND THEIE USES 



rapid shelling out of the inner rings if the inside 

 be exposed. 



"By girdling standing timber the process of 

 seasoning is to a great extent anticipated. Thus, 

 in order to float the timber, which in its green 

 state is at least as heavy as water, it is the general 

 practice in Burma to cut a complete ring through 

 the bark and sapwood of the Teak three years 

 before it is intended to fell it. This stoppage 

 of all ascending sap kills the tree in a few weeks : 

 the heat of the cHmate helps the seasoning pro- 

 cess ; and, as usually about a year elapses 

 between the felHng of the timber and its delivery 

 in England, it is then fit for immediate use. It 

 is recommended that the dense Austrahan 

 timbers should, like Teak, be ringed while 

 standing. This should be done a year or more 

 before felling, and between AprU and August 

 when the sap is quiescent. The tree is most 

 thoroughly drained of its sap when thus left 

 vertical. It has, however, been objected to this 

 ■process, that it causes or intensifies heartshake, 

 and, by drying the wood too rapidly, renders it 

 brittle and inelastic." 



Into the various theories concerning the 

 chemical changes which take place during 

 seasoning, we do not propose to enter here. 

 They are not fuUy understood, but one thing is 

 certain — seasoning does not merely imply drying 



