390 NATURE STUDY AND LIFE 



If the school possesses a hygrometer, an instrument 

 for measuring moisture in the air, it will be interesting 

 to test the relative humidity in woods or well-planted 

 districts and in the hottest and driest place available, the 

 business portion of a city, for example. Without instru- 

 ments this difference is often appreciated in the moist, 

 *' soft " air of the forest. 



It has been estimated that forest fires cause a loss of 

 not less than $30,000,000 annually in this country. Ask 

 the class to collect all the data possible as to such fires in 

 the neighborhood. We have seen that not only may the 

 trees be destroyed, but the leaf mould and even the loam, 

 representing the work of the trees in enriching the soil 

 for many years, may be burned away. If practicable, 

 make an excursion to some tract that has been recently 

 burned over and study on the ground the damage to 

 timber and soil that has resulted. Inquire particularly 

 into the causes of such fires in the neighborhood and 

 consider the means of prevention ; and, finally, obtain a 

 copy of the law against setting forest fires in your state 

 and discuss its provisions with the class. 



Forest Resources. — As a national industry, forestry stands 

 second only to agriculture in number of people and 

 amount of capital employed and in value of product. In 

 connection with language lessons develop all that the chil- 

 dren know about the uses of wood and the adaptation of 

 different kinds to various purposes. A part of the work 

 in manual training may well be devoted to making a col- 

 lection of native woods to show cross, slab, and quarter- 

 cut sections, in natural state and finished in various ways. 

 Study in this connection the market price of different 



