| 
. 
157 
The period of duration of the English coal fields would 
then extend beyond the estimated period of 300 years, and the 
long night of decay and final extinction of many, if not all, the 
manufactures, and English commercial dominancy would be 
prolonged indefinitely. However, if the world continues as it 
is, long enough, such a calamity must eventually fall upon 
England, for without the ancient forests, as in the time of the 
British and Saxon periods, and at the Norman Conquest, and 
without a supply of coal, she must naturally descend to a con- 
dition similar to that through which she struggled for so many 
centuries, and before becoming the grand signal and guiding 
post in the advancement and civilization of the world. 
If we estimate the total amount of coal to be extracted 
from the workable seams over one foot in thickness, there 
would exist in the Forest of Dean, in the year 1888, the 
quantity of 248,643,640 tons available for use. The amount of 
coal raised in that year amounted to 817,818 tons, being an 
increase on the production for 1883 of 93,936 tons. 
At the same-date the coal remaining for future extraction 
in the South Wales coal field amounted to 36,174,294,777 tons, 
and during that year the total output amounted to 19,594,507 
tons. 
This field therefore contains 145 times more coal than the 
Forest of Dean, and its output being 23°95 times greater. 
Although the Bristol coal field contained at the same date 
24-5 times more coal than the Forest of Dean, nevertheless the 
output from the latter was nearly double that of the former. 
Supposing the general increment in the future to be con- 
stantly the same as it was between 1883 and 1888, the time of 
duration of these coal fields may be calculated to a considerable 
degree of accuracy, but if it should vary, then the time of 
duration would be extended or diminished according to circum- 
stances. 
However, I apprehend that the supply of the Dean Forest 
coal field will commence to fall off long before the South 
Wales coal field. The thicker, more accessible, and profitable 
seams of coal will naturally become exhausted first in Dean 
