1 86 ECONOMICS OF FORESTRY. 



removal or harvest of a neighboring stand. Since 

 the prevailing winds in the northern zone come 

 mostly from the western direction, it is sought to 

 secure an arrangement of the stands of different 

 age in series (a " felling series "), so that the old 

 and tall timber is found at the eastern end, the age 

 classes grading off to the west, the youngest at the 

 western end, and the tops of the series of stands 

 ideally appearing like a roof slanting down from 

 east to west. It is apparent that, under such an 

 arrangement, the old timber can be harvested and 

 reproduced without exposing any stands to the 

 force of the wind, and the young timber is growing 

 up under the influence of winds and becomes wind- 

 firm. 



The greatest danger to forest properties, how- 

 ever, is fire, and the protection against this most 

 unnecessary evil, re§ulting mainly from man's care- 

 lessness, absorbs a large part of the energy of the 

 forester. Proper police, but also silvicultural meas- 

 ures, reduce the amount of danger and damage. 



The damage which fire occasions is very vari- 

 able, according to a variety of conditions. Most 

 forest fires are confined to the forest floor, running 

 in the litter and young wood, scorching the older 

 trees merely ; yet, under favorable conditions, the 

 fire may run up the trees, becoming a crown fire 

 and propagating itself from top to top and throw- 

 ing firebrands and sparks to the ground, often for 

 long distances. 



