ADDRESS, hii 
enabled the plants of the carboniferous period to wrest the carbon they re- 
quired from the oxygen with which it was combined, and eventually to deposit 
it as the solid material of coal. In our day, the reunion of that carbon with 
oxygen restores the energy expended in the former process, and thus we 
are enabled to utilize the power originally derived from the luminous centre 
of our planetary system. 
But the agency of the sun in originating coal does not stop at this point. 
In everyzperiod of geological history the waters of the ocean have been lifted 
by the action of the sun and precipitated in rain upon the earth. This has 
given rise to all those sedimentary actions by which mineral substances have 
been collected at particular localities, and there deposited in a stratified form 
with a protecting cover to preserve them for future use. The phase of the 
earth’s existence suitable for the extensive formation of coal appears to have 
passed away for ever; but the quantity of that invaluable mineral which has 
been stored up throughout the globe for our benefit is sufficient (if used 
discreetly) to serve the purposes of the human race for many thousands of 
years. In fact, the entire quantity of coal may be considered as practically 
inexhaustible. Turning, however, to our own particular country, and con- 
templating the rate at which we are expending those seams of coal which 
yield the best quality of fuel, and can be worked at the least expense, we 
shall find much cause for anxiety. The greatness of England much de- 
pends upon the superiority of her coal in cheapness and quality over that of 
other nations; but we have already drawn from our choicest mines a far 
larger quantity of coal than has been raised in all other parts of the world 
put together, and the time is not remote when we shall have to encounter 
the .disadvantages of increased cost of working and diminished value of 
produce. 
Estimates have been made at various periods of the time which would be 
required to produce complete exhaustion of all the accessible coal in the 
British Islands. These estimates are extremely discordant; but the discre- 
pancies arise, not from any important disagreement as to the available quan- 
tity of coal, but from the enormous difference in the rate of consumption at 
the various dates when the estimates were made, and also from the different 
views which have been entertained as to the probable increase of consumption 
in future years. The quantity of coal yearly worked from British mines 
has been almost trebled during the last twenty years, and has probably in- 
creased tenfold since the commencement of the present century; but as this 
increase has taken place pending the introduction of steam navigation and 
railway transit, and under exceptional conditions of manufacturing develop- 
ment, it would be too much to assume that it will continue to advance with 
equal rapidity. The statistics collected by Mr. Hunt, of the Mining Record 
Office, show that at the end of 1861 the quantity of coal raised in the 
United Kingdom had reached the enormous total of 86 millions of tons, and 
that the average annual increase of the eight preceding years amounted to 
23 millions of tons. Let us inquire, then, what will be the duration of our 
coal-fields if this more moderate rate of increase be maintained. 
By combining the known thickness of the various workable seams of coal, 
and computing the area of the surface under which they lie, it is easy to 
arrive at an estimate of the total quantity comprised in our coal-bearing 
strata. Assuming 4000 feet as the greatest depth at which it will ever be 
possible to carry on mining operations, and rejecting all seams of less than 
2 feet in thickness, the entire quantity of available coal existing in these 
Islands has been calculated to amount to about 80,000 millions of tons, 
