66 FORESTRY 



pels forest destruction. Attempts have been made to ex- 

 empt plantations from taxation for a term of years, or 

 to give rebates on taxes for the preservation of small 

 tracts of woodland in connection with farms. But these 

 laws have not effected any improvement in the general 

 situation and are mostly unoperative. The principle 

 which meets with most favor among reformers is to tax 

 annually only the land, on the basis of wild or unproduc- 

 tive lands in the vicinity, and to tax the timber at the time 

 it is cut. If this can be done, lumber will bear a fair but 

 not undue burden of taxation, and timber may be cut or 

 held at the owner's convenience. The private owner who 

 desires to devote otherwise worthless land to growing 

 trees should be assured of the protection of the state, to 

 his investment, instead of as at present being left at the 

 mercy of local tax assessors. 



IX. FOREST MENSURATION. 



Since forestry is a business as well as an art, it is im- 

 portant to know what returns will be received from the 

 use of land for tree production. The growth of trees in 

 size, and their age, can easily be measured in all temperate 

 zones, since the trees have a seasonal growth, and lay on 

 annual rings which are usually quite distinct, although 

 much more so with some species as pines and oaks, than 

 with others as maple or basswood. Sometimes two rings 

 will be joined in the same year, due to interruption in 

 growth by reason of drought or defoliation by insects. But 

 the extra or false ring can often be detected by its not being 

 complete around the whole circumference of the tree. 

 Since the age of a tree can be found by counting the rings 

 on the stump, the measured volume, in board feet, or cubic 

 feet, gives the average rate of growth of tree during its 

 life. If the stump is high, it mav have taken the seedling 

 two or three years to reach that height, in which case this 

 period must be added to the age of the stump to get the 



