Growth of Red Pine in Ontario. 171 



twenty and forty years ago. This was done for the 45 trees on 

 which the calculations already given were based, and with the 

 following results : The logs were being taken down to five inch 

 tops, and as they were unusually sound and straight and had an 

 average taper of only 2.1 inches for each 16 foot log, the board 

 measure was computed by the International Log Rule, which is 

 probably very close to the mill tally. On this basis the present 

 contents of the logs from the 45 trees is 7,640 board feet; 5,775 

 feet twenty years ago; and 3,990 feet forty years ago. On a 

 simple interest basis this would show an increase of 32-3 per 

 cent, or a yearly average of 1.615 per cent, for the last twenty 

 years; and an increase of 91.4 per cent, for the last forty years, 

 or a yearly average of 2.285 P^^ cent.; or by compound interest 

 1. 41 and 1.636 per cent, respectively. 



Applying the Schneider-Borggreve formula, -— — , to determine 



nd 



the present rate of growth, it is found to be only .9 per cent.; 



the growth of the stand has practically ceased and only a rise in 



market prices would justify leaving it to increase in volume. 



