256 



INDUSTRIAL PLANTS 



p^:??^rrp^?f^^??7rp7F?E^^ 



^rr>x I 



C 



L IG. 2o5.— iraiij^vcrsu .section of white <i;iK 

 wood, ^ (Hartip.) 



J^^^f'^p|ffliff]|j'|t|lf(ii|trf|5ffp4 



1 M 





M 



Ml 



M 



I I 2 .(i ^Ti in^"\ ( rs(_ s < Imn \ i\ni v. tu d i 

 (Hirti ^ j 



I'n;. -37. — Transverse seetion of tish lyrjod, i. 

 (Hartig.) 



l'"ui. li3S. — Traiisversi' section nf walnut 

 wuud, I. (Hartig.) 



jilanks, and is quite un- 

 suited for most of the 

 uses of ordinarj' wood. 

 Like bamboo, the harfl 

 sheU of tlie coconut, 

 and otlier materials 

 sharing some of the es- 

 sential properties of or- 

 dinary wood but differ- 

 inp; from it decidedly in 

 structure, t h e palm- 

 trunk can scarcely be 

 i-egarded as a true wood 

 at all. Such materials 

 are best called pscii'hj- 

 woods, to distinguish 

 them from true 'Woods 

 which a r c a 1 \t a )' s 

 formed liy a caml)iuni 

 layer. 



73. True woods. 

 The following include 

 the more important 

 woods commonl}- used 

 in this country: — 



Oak (Figs. "235, 242, 

 243) is used extensively 

 for heavy construction 

 in common carpentry 

 and shipbuilding, and 

 in car and \\-agon work 

 on account of its ex- 

 traortlinary strength ; 

 also in the manufacture 

 of farm implements and 

 parts of machinery' be- 

 cause of its hardness 

 and toughness, while its 

 u n u s u a I durability 



