TIMBER: FORESTRY 395 



effect to the interiors of rooms, railway cars, and so on, fin- 

 ished with wood, which could be obtained with other materials 

 only with much difficulty and expense. It is difficult to imag- 

 ine how beautiful furniture of moderate price, such as is made 

 from our ornamental woods, could be made from any metal. 



365. Wood as fuel. Although coal is the fuel of the world's 

 great industries, yet there are large areas throughout which 

 wood is still the principal fuel. All kinds of wood can be 

 burned, but for certain purposes those kinds are preferred 

 which make an abundant flame, or which leave solid beds of 

 glowing coals. In general the heating effect of well-dried 

 wood when burned is nearly (though by no means exactly) 

 proportional to its weight per cubic foot. The fuel value per 

 cord is therefore somewhat dependent on the weight per cord, 

 and the heaviest woods, such as hickory, sugar maple, most 

 of the oaks, hackberry, and some kinds of ash, are the best .for 

 burning. For certain purposes where a concentrated smoke- 

 less fuel which lights easily and does not readily go out is 

 required, charcoal is employed. Generally the heaviest woods 

 make a dense charcoal of great heating power. 



366. Forestry. Forestry is the art of forest management. 

 It should be based on the scientific study of woodlands. This 

 study may cover all such topics as the distribution of forests 

 over the earth's surface, their dependence on soil and climate, 

 and their own influence upon these. It also discusses their 

 composition as plant communities, 1 their progress from in- 

 fancy, through youth and maturity, to old age, and their rela- 

 tions to the animal world. The utility of forests as sources 

 of timber is a forestry topic which stands foremost in the 

 estimation of the public. 



It is evident that forestry is so extensive a subject that in 

 a portion of a chapter like the present one only a few of its 

 most important subdivisions can be briefly discussed. Every 

 well-informed person should at least know in a general way 

 what forestry is, since the maintenance of some of our best 



i See Sect. 447. 



