2 Definitions. 



ment and calculation concerned in forest lands, materials, manage- 

 ment, working, or revenues. 



(e.) From mechanics, it applies the various agencies employed in 

 cutting, transporting, and manufacture of wood and timber in every 

 form. 



(/.) From physics and meteorology, it determines the various 

 questions of atmospheric influence and of climate that may arise, 

 whether as cause or efiect, and seeks to learn how these may be im- 

 proved to best advantage, and, in some cases, controlled. 



(</.) From political economy, it applies the principles that deter- 

 mine questions of supply and demand, of public policy, and of 

 financial profits, the interests that are involved, and their mutual 

 dependence, the laws of trade, as they concern forest products or 

 properties, and whatever principles may relate to their creation, 

 production, or management. 



5. An intelligent system of Forestry aims to irnpart knowledge as 

 to the conditions best adapted to cultivation, the best methods of 

 securing a growth of trees by seeding or planting, .the use of meas- 

 ures that shall secure their thrifty growths, protection from injuries, 

 natural renewal at period of full maturity or time for use, and a 

 constant tendency toward improvement of the products. 



6. A Tree, is a plant having a woody root, trunk, and branches. 

 We generally apply the term Aruh to trees that are less than fifteen 

 feet in height at- maturity, and the term hiu>li to those that grow to 

 six feet in height or less. These terms are however arbitrary, in 

 their use, and can not be with certainty applied to any species. 



7. Trees may increase from within, as in the case of palms, or by 

 the deposit of wood in annual layers under the bark. The former 

 have no bark proper, and are called Endogenous, a term signifying 

 "growing from within." They are represented in the Southern 

 States by the palmetto (Sahal palmetto) , and a few other species, but 

 on account of their slight relative importance as forest trees, they 

 will be uo further noticed in this work. The latter are termed Eb- 

 ogenous, a term signifying " growing from without," and increase by 

 the deposit of new layers of wood on the outside, under the bark. 

 This great division includes, with the above exception, all of the na- 

 tive aud naturalized trees of the United States. 



8. A Species, when used in Forestry, is understood to mean a group 

 of trees or other plants, resembling iu the details of their structure, 



