UNIVERSITY 

 CONVERSION AND SEASONING. 



favourable conditions for the growth of those fungi which are the 

 main causes of decay. If completely submerged, or buried, or 

 when once dried and kept so, timber may last indefinitely. The 

 piles in the Swiss lake-dwellings must be many centuries old : 

 wood of Juniperus Oxyddrus buried in the island of Madeira has 

 remained undecayed and fragrant for four hundred years; and 

 Spruces three to four feet in diameter have been observed in the 

 moist forests of north-west America growing on the prostrate but 

 still sound trunks of Thuya gigdntea. 



By girdling standing timber the process of seasoning is to a 

 great extent anticipated. Thus, in order to float the timber, 



FIG. 43. Plank badly laid, with the inside, or inner rings, upward. (After 

 Laslett.) 



which in its green state is at least as heavy as water, it is the 

 general practice in Burmah 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 climate helps the seasoning process ; and, 

 as usually about a year elapses between the felling of the timber 

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

 has, however, been objected to this process that it causes or 

 intensifies heart-shake, and, by drying the wood too rapidly, 

 renders it brittle and inelastic. 



Seasoning of some kind is, in all other cases, rendered impera- 

 tive by the changes in volume, irregular shrinkage, or warping, 

 that all green woods undergo under the influence of changes in 

 atmospheric temperature and moisture, especially in their cross 

 sections. So important is it to avoid this warping in furniture, 

 wheelwright's work, etc., that it is a common practice to block 



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