298 TIMBER 



amongst others, we are indebted for hundreds of illus- 

 trated sections showing the structure of wood. It may be 

 mentioned that so far back as 1770, in a book on " Con- 

 struction of Timber," by John Hill, M.I)., there are some 

 excellent microscopical sections given of a good many 

 European timbers. 



This is an excellent and easy method of distinguishing 

 different timbers ; by this means we can tell hickory from 

 ash, and oak from either ; beech from birch and sycamore, 

 though at a casual glance they appear very similar. 



A good log of timber has a clear ringing sound when 

 struck on the end with a hammer, and this is particularly 

 noticeable in the pines and firs ; a dull sound denotes decay 

 or defect somewhere, although it may be only local and not 

 of serious import. The least knock or even scratching 

 with a pin at one end of a good log can be distinctly heard 

 at the other end, even over a length of 60 ft., if the timber 

 is sound and healthy. 



Resonance is a quality in timber to which particular 

 attention has to be paid by those requiring wood for musical 

 instruments, spruce and silver fir being the favourites 

 for this purpose, and it has to be wood free of defects and 

 of uniform structure and growth. 



Where timber is referred to as subject to the depredations 

 of the white ant and other boring insects, this only applies 

 to its native districts or the tropics. In climates such as 

 that of Great Britain timber is rarely attacked by boring 

 insects to any extent until it attains a great age, and timber 

 obtained from the regions infested by these pests is no 

 more liable to attack in Europe than native timber or timber 

 brought from the Baltic or North America ; but, on the 

 other hand, European or North American timber imported 

 into the tropics is quite as liable to attack as, probably more 

 so than, native timber. 



