648 GEOLOGY OF OHIO. 



The most careful estimates T can make indicate that we have in all 

 these townships, in this single deposit, the equivalent of a continuous 

 sheet of coal averaging ten feet in thickness and covering an area of 

 100,000 acres. Estimating a cubic yard of such a body ot coal to weigh 

 one ton, and that it could all be mined, this one district is capable of 

 producing over 1,600,000 000 tons of coal, or over 100,000,000 tons in 

 excess of all the coal mined in the United Kingdom of Great Britain 

 from 1854 to 1870, both inclusive. 



The average annual production of coal in the United States for the 

 last three years past is a little under 48,000,000 tons. This coal-field 

 would suffice to produce that amount continuously ea ^h year for thirty- 

 three years. It is not, however, so much the increased thickness as the 

 remarkable change in the character of this coal that has attracted to it 

 so much attention. Coal No. 6 is the most persistent seam in the State, 

 and furnishes a large portion of the coal mined in it. It is ordinarily a 

 melting or coking coal, with high heating power, an excellent steam 

 and mill coal, but contains too much sulphur to make a valuable coke 

 for the smelting furnace. It leaves a peculiar purple ash, so that in 

 nearly all the counties of the State where this coal is u-ed the refuse 

 heaps from the stoves and furnaces discloses the fact to the trained 

 observer, who is rarely misled by this indication. But in the Great 

 Vein Region this coal becomes very hard and dry burning. It melts or 

 swells in the fire, but slightly, is remarkably free from sulphur, and 

 burns with littie smoke, leaving a white ash. It is not an open burn- 

 ing, iiut a remarkably dry burning coal. It has not, generally, the finely 

 laminated structure and thin bands of charcoal of the Block Coal, which 

 causes the latter to split up so readily, when fired, but, when best de- 

 veloped, is almost as compact and homogenous as anthracite, and, after 

 the volatile matter is driven off, leaves a mass of glowing coals much 

 resembling an anthracite fire. It partakes somewhat of the character of 

 cannel, and in places, especially in the upper bench, resembles a splint 

 coal. It has been classed as both of these, and has been sold in New 

 York as "Ohio Cannel." The appearance of the cual, and its chemical 

 analysis indicate, and practical tests have demonstrated, its great excel- 

 lence for smelting iron, and good results are obtained from its use in the 

 smelting furnace without any mixture of coke. As a domestic fuel, it is 

 not excelled by any coal in the State. Careful comparative tests, made by 

 weighing large quantities of the coal and burning it in grates and stoves, 

 and comparing the character and quantity of the residuum, show that, on 

 the average, it leaves a rather larger percentage of ash than Coal No. 1, 

 but a less quantity of cinder, burning almost entirely to a fine white ash- 



