EXOGENOUS TREES. 9 



ive markings are in a general way indicated on the boards in 

 the figure. 



Logs are sometimes sawn into quarters and then into pieces 

 crossing and exposing the yearly rings. (See Fig. 

 4.) These "quarter-sawn" surfaces are struc- x< 

 turally stronger and better, but are, by reason of ^ 

 waste or small pieces, more costly than others. The \ 

 pith-rays of some woods, such as oaks, are very FlG 4> 

 prominent when split as they are in "quarter- 

 sawing," and the appearance of such woods is consequently 

 improved.* 



Exogenous trees are divided into broad-leaved trees and 

 needle-leaved conifers. The broad, flat leaves of trees such 

 as oaks and chestnuts gave rise to the former term, while the 

 narrow resinous leaves of the pine and hemlock gave rise to 

 the latter. The woods of the former group are usually referred 

 to as hard woods, although some of them are very soft; those 

 of the latter group are referred to as soft woods, although some 

 of them are very hard. Most, but not all, of the broadleaf 

 trees are deciduous, that is, they change their foliage every 

 year; and most, but not all, of the needleleaf trees are ever- 

 green, that is, the foliage is persistent. Needleleaf trees are 

 also known as conifers, that is, cone-bearers. 



It is usual to associate the terms broadleaf, deciduous, and 

 hard wood ; and likewise the terms needleleaf, conifer, ever- 

 green, and soft wood. While generally correct, this is, as 

 seen, not always so. A better division is into broadleaf trees 

 or woods, and needleleaf conifers. 



* Some woods, as birdseye maple, are well developed by the rotary cut. 

 A revolving log is advanced against a tool which pares a broad thin ribbon suit- 

 able for veneered work. 



