STEVENSON— INTERRELATIONS OF FOSSIL FUELS. 41 



mass in one shaft show 40, 30 and 31.7 per cent, of volatile in 

 the pure coal, with 10.82, 5.10 and 9.52 of ash. In a shaft, north 

 from James River, the 4 divisions of the coal show a difference o£ 

 aboat 4 per cent, in volatile, while the ash is 5.20, 22.20, g.8o and 

 22.60 in the several divisions. 



Stone, in his report already cited, has given analyses of the 

 coal at Leakesville in the Dan River area of North Carolina. The 

 seam is an insignificant lens but is apparently the most important 

 deposit in that area. It is in two benches separated by only 2 feet 

 of micaceous shale but the composition is very different. The 



lower bench is anthracitic and the upper bench is a high-grade 

 bituminous. The sulphur in both is at most little more than a half 

 of one per cent. The ash is very much higher at most of the North 

 Carolina localities, occasionally reaching 39 per cent, in " best coal." 



It may be well to gather the notes respecting ash as presented 

 in the several analyses. The conclusions at best can be merely tenta- 

 tive because analyses, in almost all cases, appear to have been those 

 of hand specimens supposed to represent the average of the seam 

 as shipped : and there are comparatively few showing the com- 

 position of coals not regarded as fit for working. It is sufficiently 

 clear that conditions were not the same in all portions of the area 

 occupied by any seam or during the time of its accumulation. 



In the Jurassic region of Austria, the coal of one seam near 

 Bernreuth, though externally resembling good coal, has 42 per cent. ; 

 near Gresten, the same seam has only 3.9 per cent. The ash is low 

 at Hinterholtz but at Grossau it rises to 10 per cent. At Pechgraben 

 the average of all analyses is 17. These in all cases are from 

 coals which are mined. No attention was paid to other seams be- 

 cause they are " dirty." Similar conditions exist in the Triassic 

 region of Austria. Near Kleinzell, the highest seam has 14 per 

 cent. ; near Lilienf eld, the good coal, with little more than 7 of ash, 

 is in the middle seam ; near Kirchberg, the coal mined has from 



