SCIENCE. 



99 



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 187,112,857 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 1 86 years. 



The present product of the Anthracite coal fields is 

 (1878) as follows : 



6,282,226 tons. 



Southern 50 Collieries 



Middle 161 " 



Northern 132 " 



3,237,449 

 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 64,661,401 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 2,210,710,091 tons of 

 coal; and, more wonderful still, exported only 222,- 

 196,109 tons — say ten per cent — consuming the rest 

 within her own borders. 



The average increase of her annual output has been 

 3^ per cent. Will it so continue ? Or has she reached 

 the summit of her industrial greatness and commercial 

 supremacy, aid 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 



45.746.930.555 



34,461,208.913 



9,843,465,930 



155,680,000 



56,246,000,000 



101,992,930,555 



34,461,208,913 



9,843,465,930 



182,680.000 



Scotland 



No < stimatf. 

 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 ? 



