i04 AGEICLLTURE OX THE RHINE, 



soil and climate, such as the author of this table assumes, 

 to about the ninetieth year ; the increment is less after that 

 period, but the value of timber of so large a size as a ti'ee 

 attains in 100 or 120 years is proportionately g'reater than 

 at an earlier period ; hence, up to 120, it is more profit- 

 able to leave the aged trees, if sound, than it would be to 

 supplant them by a younger stock. This is still more 

 applicable as a rule for oaks, the size of which is so 

 important for machinery, that a thickness of a few inches 

 with sufficient length of trunk often makes a difference in 

 the value of the tree of thirty to fifty per cent. 



The fourth column shows the d:sjx)sable quantity of 

 timber, brushwood, and branches that the forester, under 

 usual circumstances, can draw at the several periods in- 

 dicated in the first column from a morgen of land. As 

 however the seasons, the destructive effects of insects, 

 and incidental circumstances make the precise period of 

 felling a matter of local calculation, while the state of 

 the market occasionally hastens or retards the operation, 

 the profit or lass is materially affected by the forester's 

 judgment in availing himself of all advantages. In se- 

 lecting the trees to be felled, he must know the qualities 

 of each individually, as a farmer studies the peculiarities 

 of his beasts. Some trees are of more rapid growth than 

 others ; these are of course left as long as this quality 

 shows itself, and such as haye increased but little in 

 bulk between two periods of foiling are selected as the 

 first disposable. A forester who loves his task is thus in 

 constant converse with nature, and it is common to find 

 men in the forest department more enthusiastically at- 

 tached to their profession than in almost any other branch 

 of the public service. The feeling thus awakened is 



