VII.] DESICCATING, ETC. 8i 



frames set at an angle of about 30°, and it was found 

 that it afforded no good results. The butt-ends dried 

 far too quickly to allow the sap juices, which drained 

 to the lower part, to evaporate ; as a consequence, decay- 

 was rather accelerated than otherwise. 



Steaming or boiling unseasoned timber will fit it 

 quickly for employment in architectural work, but it 

 should only be resorted to in case of necessity, as it 

 takes from its strength, and adds nothing to its 

 durability. 



Seasoning in chambers heated to a high temperature 

 is practised to some extent on thin planks, boards, and 

 other small and light material, but it cannot be carried 

 out on timber of large scantlings, owing to the great 

 weight and the difficulty there is in handling it ; besides, 

 the storage room required for any considerable quantity 

 of it would be so enormous that it may be looked upon 

 as next to impracticable. Very great care is necessary 

 in drying boards by this desiccating process ; the ends 

 need always to be clamped to prevent them from splitting 

 and warping, and they must be firmly secured by thin 

 laths being placed between them. Ordinarily wood thus 

 dried loses in strength, and in coloured woods there is 

 this further drawback, that they generally turn pale and 

 lose their lustre. 



A patent was taken out in France about the year 

 1 861, by M. de Lapparent, Director of the French Dock- 

 yards and Inspector of Timber for Naval Purposes, for 

 carbonising timber by means of inflammable gas (either 

 pure hydrogen, or, better still, lighting gas) directed 

 by means of a tube against every part to be carbonised, 

 just as one would direct a jet of water from a fire- 

 engine upon the flame to be extinguished. No doubt 



G 



