74 NOTES ON FORESTRY. 



the length of rotation at which it would be desirable 

 to cut it, unless large timber of the class is worth 

 more per cubic foot than small timber; and this 

 being ordinarily the case, the timber should be 

 allowed to stand until the annual falling off in 

 increment is barely compensated by the increased 

 money value. Moreover, between the sixtieth and 

 the hundred and twentieth year we may count on 

 being able to thin out to the extent of one-fifth the 

 quantity of stock at final clearing without detriment 

 to ultimate results. 



German forest literature abounds in elaborate 

 tables of the growth at various stages of every 

 description of tree in the German forests, but these 

 would be useless as a basis for calculating the rate 

 of increment in our Indian forests, especially in the 

 Plains, where the growth during the first period of 

 twenty years is vastly in excess of anything known 

 in Europe. The corresponding statistics concern- 

 ing Indian trees must be studied by practical re- 

 search in the forest itself. 



The following tables, giving the cubic contents 

 of an oak, a beech, and a Scotch fir forest at their 

 several stages, may be taken as indicating the 

 general ratio of increase of each class within itself ; 

 but being compiled by three different authorities, 

 they must not be taken as indicating the relative 

 growth of the three classes. 



