HOCKING VALLEY COAL FIELD. 971 
FIGURE Cx 
STRUCTURE OF NELSONVILLE COAL IN 
THE SNAKE HALLOW MINE OF 
W.B.BROOKS & SON. 
Cry Slate, overloran with sandstone. 
Rah Poor BAG RU NOLO ORONO Ne : 
S\ ake maxed ww wien Sook. See Ree 
SS i SNe | 
Wone Coat, Ro oF ol BNO ee a ee 
\S RR Vet bene NERS et AC eees Nien ae a See UE eee 
Seeeras LAVsh 
| Ona ENWrcrm enlace dani Wl! Fe 
FEAx stb _ SONG Mas tee da NG 
Lower encla.. gate bade et leon ells 
¥ AY Q QV oay — 2H ~ 5 + - —} 
treacherous to some extent, often falling to the sandstone, but the roof 
that they form is, after all, somewhat better that it looks. In the 
normal seam the thin layer of bone coal that comes in above the upper 
bench makes an excellent roof. The coal splits naturally at this point, 
and the bone coal, with the black slate above it, is strong and unaffected 
by the air. 
As usual in the seam, there is a band of soft coal directly over the 
second slate. Aside from its friable nature this band is not especially 
objectionable, but the character of the output would be improved if 2 
to 4 inches were split off from the upper bench. ~When sent out, as it 
generally is, it mainly turns to slack before it reaches the consumer. 
The coal cuts easily. Faces are remarkably bright and regular. 
The end joints or cutters divide the coal into blocks 8 to 12 inches in 
thickness. The direction of the face is about 10° east of north. 
Irregularities in the coal itself are very rare. A single clay 
vein in the present workings cuts across 2 entries, in a north-easterly 
direction, but, as a whole, the coal is undisturbed and regular. 
The fire-clay on which the coal rests is unusually thick. Itisa 
