22 REPORT ON THE FOREST TIMBER OF 
the abundance of mineral coal, the value of charcoal iron is: 
such as to warrant the building of charcoal furnaces where 
both timber and ores are abundant; and as the consumption. 
of timber in iron-making rapidly sweeps away the old forest, 
it is of no small importance that nature instantly sets about 
replacing in kind what is consumed from year to year by the 
furnace. 
The statistics of Mt. Savage Furnace, which may be taken. 
as a representative instance, show a consumption of about 
twelve thousand cords of wood per year, or for an average 
blast of a little more than three thousand tons iron product. 
Allowing thirty to thirty-five cords of wood to the acre—a. 
low estimate for hill and valley—gives a yearly decrease in, 
forest area of from three hundred and fifty to four hundred 
acres. From the best information obtained in this furnace 
region, it appears that from twenty-three to twenty-five years’ 
growth is required to give an average of thirty to thirty-five 
cords of wood per acre. From this it appears that a tract of 
nine to ten thousand acres is sufficient for the establishment of 
a perpetual charcoal furnace of ordinary capacity. 
22 
