30 t-0 A tt 60 70 #0 <JO /OO 1/0^ 







e 



p 



er acre 



>% /^?000 



$000 



7000 

 6000 

 SQOO 



HT 



Fig. 4. Spruce; Middle and North Germany; Sites I-V; Normal Yield of 

 Main Stand in cubic ft. per acre. Also the points indicating at what age the average 

 tree attains a diameter of 8", 10" and 12", and a height of 40 ft., 50 ft., etc. Only 

 wood 3" and over is here considered. 



153 



