I O4 NO TES ON FORES TJ? Y. 



years will probably be fully as high as in any 

 similar period before conversion. 



In the third period, the first five years would 

 be occupied in selecting timber from A, which 

 would then be laid up, and the next fifteen in 

 clearing off D (taking the oldest trees first), with 

 similar results to the previous twenty years. 



We have now behind us D, covered with seed- 

 lings under twenty years, E with trees from 

 twenty to forty years, and before us CBA, the two 

 former of which carry timber from sixty to 120 

 years, and the latter from seedlings to eighty 

 years ; and taking C in hand, and cutting out the 

 oldest trees first, we are able to clear the last at 

 from seventy-five to eighty years old. 



B being similarly treated in the next twenty 

 years, the trees would be cut out at from ninety- 

 five to 140 years old. 



Finally, A, being similarly treated, would give 

 trees from seventy-five to 120 years. 



At the expiration of this period, we should 

 have five blocks, in each of which there is a grada- 

 tion of twenty years in age ; but to complete the 

 transition we want a hundred blocks in which the 

 gradation is by annual steps ; and we may not 

 be able to divide any of these five blocks into 

 twentieth parts, and secure anything like a yearly 

 gradation of age in the blocks. 



