METHOD OF YALUIKG GROWING TIMBER. gQO 



Here again we may suppose, that the forty-eight feet 

 bole, by swelluig faster than the sixty feet bole, may ex- 

 ceed it in measure at sixty years of age ; and this it would 

 do, were the girt increased only half an inch* And if the 

 thirty-six feet bole was increased two inclies in girt, it 

 would exceed both the forty-eight and sixty feet boles. 

 But trees of such swift growth are frequently cut down 

 before they are sixty years old. At forty years of age the 

 thirty-six feet bole, if it swell no faster than the forty-eight 

 feet bole, v/ill contain more timber if measured according 

 to the present erroneous method. (The greater difpro- present me- 

 portion there is between the two ends of a piece of timber, thodofme*- 

 the more disadvantageously it measures, when the girt is neous, 

 taken in the middle.) I suppose that in timber of this 

 swift growth, the longer boles are frequently not worth 

 more per foot than the shorter boles ; therefore, in this 

 case, that length of bole should be fixed on, which is likely 

 to measure most at the period when the trees are intended 

 to be felled. 



Whatever the lengths of the boles of trees increasing as 

 above may be, their increase is five per cent per annum, 

 one year after their girt in the middle is 20 inches, but not 

 longer. 



It appears from the last observations and calculations, 

 that the annual increase in the boles of trees by their 

 growth ceases to be equal to five per cent per annum some 

 time between forty-six and sixty years of age, according as 

 the boles are shorter or longer. 



But it being generally allowed, that oak trees, of a size Size of oaks 

 fit for the navy, require to grow from eighty to one hundred ^^^ ^^^ "^^ 

 and fifty years, according to the quality of the soil ; and it 

 is so stated in the eleventh report of the commissioners ap- 

 pointed to inquire into the state and condition of the 

 woods, forests, and land revenues of the crown ; I have 

 therefore been calculating tables, showing what the propor- require^ a very 

 tionably advanced prices should be, at different periods, up ^'g*^ P^^e. 

 to one hundred and fifty years, to pay the proprietors for 

 letting their trees stand to those periods. These prices, 

 especially at the later periods, very greatly exceed any th^it 

 have ever been given. It certainly has been much the 



interest 



