THE PRINCIPAL SPECIES OF WOOD. 



darkened, remains practically uninjured. The later oaken 

 vessels were iron-fastened,* and cabinet-makers now employ 

 that metal in joining oak. The barks of all species are also 

 so charged with acid as to be used in the tanning of leather. 

 The several kinds of oak are commercially divisible into 

 three general groups, white oak, red or black oak, and live 

 oak.f The principal species affording woods under each head 

 are as follows: 



White Oak. Red or Black Oak. 



White Oak (Q. alba). Red Oak (Q. rubra). 



Cow Oak (Q. michauxii). Pin Oak (Q. palustris). 



Chestnut Oak (Q. prinus). Spanish Oak (Q. digitata). 



Post Oak (Q. minor). Yellow or Black Oak 

 Bur Oak (Q. macrocarpa). (Q. velutina). 

 Pacific Post Oak (Q. gar- 

 ryanna). 



Live Oak. 



Live Oak (Q. virginiana). 

 California Live Oak (Q. 



agrifolia). 

 Live Oak (Q. chrysolepis). 



Oak trees are char- 

 acterized by oblong, 

 thin-shelled kernels, 

 protruding from hard 

 scaly cups and called 

 acorns. The foliage is 



WHITE OAK RED OAK 



(Quercus alba). (Qttercus rubra.~) 



sometimes deciduous and sometimes 

 evergreen. Most oaks require many 

 years to reach maturity, but are then 

 long-lived. Fifty of the nearly three 

 hundred known species of oak are na- 

 tives of the United States and Canada ; 

 ...... j r 11 LiVE-OAK (Qttercus virginiana) 



all but four become trees under favorable 



conditions. Quercus is from two Celtic words, quer, signifying 

 fine, and cuex, a tree. 



* Communication. Mr. Chas. H. Cramp, President Cramp Ship-building Co., 

 Philadelphia. 



f This division is also a botanical one based not only on differences in anatom- 

 ical structure of the wood itself, but on the time required by fruit in attaining 

 maturity, and on persistence of foliage (evergreen or deciduous), etc. 



