SCIENCE. 
90 
sent to market in the 58 years from 1820 to 1878, in- 
clusive. Our consumption now amounts to 20,000,000 
tons annually. The increase of production for the 
past ten years has been r 87, 112,85 7 tons. At this 
rate we shall reach our probable maximum out-put of 
50.000. 000 tons in year 1900, and will finally exhaust 
the supply in 186 years. 
The present product of the Anthracite coal fields is 
(1878) as follows : 
Southern 50 Collieries 6,282,226 tons. 
Middle 161 “ 3,237,449 “ 
Northern 132 “ 8,085,587 “ 
Total 343 “ 17,605,262 “ 
At this rate the eastern end of the northern field is 
being rapidly exhausted. The middle field, too, which 
contains the lower productive coals, is likely to cease 
extensive mining about the year 1900; while the 
western portion of the northern field, extending from 
Pittston to the western end, and the southern field 
from Tamaqua to Tremont, comprising about 100 
square miles, which contain more coal beds and 
deeper basins, must furnish the supply for the coming 
years. 
Partially successful experiments have been made to 
use petroleum as a substitute for coal to some extent. 
But is it not already evident, under the reckless prodi- 
gality of production, that this occult and mysterious 
supply of light and heat and color will be exhausted 
before the Anthracite, and can, at best, only tempor- 
arily retard the consumption of the latter ? 
As already intimated, the question of the exhaustion 
of our coal supply is scarcely more at the present time 
than a curious and interesting calculation. It has not 
yet become so grave and portentous as in Great 
Britain, where a commission, with the Duke of Argyle, 
Sir Roderick Murchison and Sir W. G. Armstrong at 
its head, was recently appointed by Parliament to as- 
certain the probable duration of the coal supplies of 
the kingdom. There it is serious indeed ; for when 
Britain’s coal fields are exhausted, her inherent vitality 
is gone, and her world-wide supremacy is on the wane. 
When her coal mines are abandoned as unproductive, 
her other industries will shrink to a minimum, and her 
people become familiar with the sight of idle mills, 
silent factories and deserted iron works, as cold and 
spectral as the ruined castles that remain from feudal 
times. 
The modern growth and ultimate decadence of this 
great empire may be calculated from the statistics of 
her coal mines. In 1800 her coal product was about 
10.000. 000 tons; in 1854 it was 64,66r,4or tons; 
and in 1877 it swelled to 136,179,968 tons. This 
period was a time of continued prosperity, when Eng- 
land ruled the world financially and commercially. In 
the 23 years from 1854 to 1876, inclusive, she pro- 
duced the enormous quantity of 2,2 10,7 ro, 09 r tons of 
coal; and, more wonderful still, exported only 222,- 
196,409 tons — say ten per cent — consuming the rest 
within her own borders. 
The average increase of her annual output has been 
3J per cent. Will it so continue ? Or has she reached 
the summit of her industrial greatness and commercial 
supremacy, and will they now decline, and with it her 
naval and military power, the subservient agent, and, 
to a large extent, the creature and result of those great 
interests ? 
Our Anthracite product, compared with the coal 
product of Great Britain, is so small as to really seem 
insignificant. The English Commission counts as 
available all coal beds over one foot thick — we count 
nothing under two and a half feet thick, nor below 
4,000 feet in depth — showing a net amount in the ex- 
plored coal fields of 90,207,285,398 tons; estimated 
amount in concealed areas, 56,273,000,000 tons ; total, 
146,480,285,398 tons, distributed as follows: 
Explored. 
Unexplored. 
Total. 
England 
Wales . . . 
45.746,930.55s 
34,461,208,913 
9,843,465,930 
155,680,000 
56,246,000,000 
101,992,930,555 
34,461,208,913 
9.843,465.93° 
182,680,000 
Scotland 
Ireland 
No « stimat^. 
27,000,000 
Total 
90,207,285,398 
56,273,000,000 
146,480,285,398 
The exhaustion of this magnificent mass of coal at 
this present rate of increase, viz.: three and a half per 
cent, per annum, is estimated by Professor Jevons as 
follows : 
1876, actual output 133,300,000 tons. 
1886, estimated annual output 186,600,000 “ 
1896, “ “ 261,200,000 '• 
1906, “ “ “ 365,700,000 •* 
1916, “ “ “ 512,000,000 “ 
1926, “ “ “ 716,800,000 “ 
1936, “ “ " 1,003,500,000 “ 
Thus in sixty years the output would be nearly eight 
times the present amount, and about one-fourth of the 
total amount to be found in Great Britain. 
This vast estimate seems too enormous. It does 
not allow for great loss when cost of labor and much 
competion will prevent the working of small coal beds 
under two feet in thickness, or for the cost of mining 
when from 2000 to 3000 feet deep. Nor is it possi- 
ble that Great Britain’s industries and export trade 
combined will ever require so great a quantity. Modern 
discoveries and improvements, in applied science, tend 
to diminish the consumption. The 8,000,000 tons 
annually required for gas-works may be materially re- 
duced by the use of the electric light. The domestic 
consumption, now equal to one-fourth the product, 
or 33,000,000 tons a year, may increase. But will 
not the iron manufactures be on the wane, and her 
coal exports — now ten per cent, of her coal product — 
fall off as those of other countries increase ? 
We have about 340 collieries and produce 20,000- 
000 tons per annum, or about 60,000 tons each. 
Great Britain has nearly 4000 collieries, and mines 
132,000,000 tons, or 33,000 tons per colliery. The 
greater the yield per colliery the less the expense in 
mining. If we decrease the number of mines and in- 
crease their capacity not only to raise the coal, but to 
exhaust a constant current of foul air and dangerous 
gases, clouds of powder smoke and millions of gallons 
of water, we will reduce the cost of mining. Most 
of the Anthracite mining in the United States is now 
done at a less depth than 500 feet vertical ; but as 
the coal nearer the surface becomes exhausted, the 
mines must go deeper and become more expensive. 
What a folly it is to boast of our world’s supply of 
Anthracite, and feverishly endeavor to force it into 
foreign markets, when we can' so readily foresee its 
end ? Would it not be wiser to limit its product, 
restrict its sale to remunerative prices, and consume 
it at our own firesides, and in our own manufactures ? 
