180 Frank Carney 



the metamorphism, it is urged, are quite the same as those which 

 metamorphose any other deposits, chiefly heat and pressure. 

 This is a subject on which httle is definitely known. Between 

 peat and anthracite there is a wide gap. The difference is chemi- 

 cal; it appears to be largely a deoxidation process. Just the fac- 

 tors that contribute to this process is the part of the question on 

 which students are not agreed. Possibly the pressure of overlying 

 sediments indurates deposits beneath, and induces chemical 

 changes. Possibly, accompanying this pressure, is heat which 

 is a strong factor in the change. The slow decay of the vegeta- 

 tion is due to micro-organisms, which evolve chemicals, that in 

 themselves may induce further chemical changes. 



In any event, it is customary to speak of anthracite as metamor- 

 phosed bituminous coal. This explanation is given practical force 

 because of the fact that anthracite coal is found chiefly in areas 

 where the rocks have been very much disturbed. In eastern 

 Pennsylvania where the strata have been sharply folded, onh- 

 anthracite coal is found. In the western part of the state, where 

 the disturbance has been slighter, the coal is bituminous. In 

 Ohio, where there has been very little disturbance, we have only 

 bituminous coal, and sometimes the less metamorphosed seams of 

 poorer bituminous coal. The theory that heat appears to be 

 connected with the change from the lower grades to anthracite 

 coal is further strengthened by a study of coal deposits in New 

 Mexico, where portions of bituminous beds next to igneous intru- 

 sions have been changed to anthracite. 



Rank of state. Ohio is one of the older states in the production 

 of coal. It has long maintained a prominent position, and during 

 the year 1908 ranked fourth in both tonnage and value. Many of 

 the coal seams in Ohio are not as valuable as others. It is to be 

 hoped that as men learn more about the nature of coal deposits and 

 their adaptation to different uses, the lower grades of coal may be 

 found of increasing commercial importance. Only in the last few 

 years have we begun to attack the question of coal scientifically. 

 Men learned early that all coals Would not coke, but they did not 

 ask themselves why; experiment eliminated the poorer coking- 

 coals. Sometimes the efficiency of a coal is very much lowered by 

 impurities acquired in process of mining; these, it has been found, 

 may be partly eliminated by washing. It has been learned, fur- 

 thermore, that furnaces and other arrangements for using the 



