172 GEOLOGY OF OHIO. 
The coal of the Cleveland Shaft, and also of the Chew bank, Brook- 
field township, ranges somewhat lower in quality, if inference may be 
safely drawn from single analyses. The results are given below in 
connection with those of two other mines: 
No. 1. Cleveland Shaft, Brookfield township... .........sscscsseccsceceees Lord. 
No. 2. Chew Bank, Brookfield township.............0csssssscscscsccsceces 3 
No. 3. High Tone Shaft, Liberty township................sscsessesesseseee g: 
No. 4. California Slope, Hubbard township................scecscessceeeoes ‘f 
1 2 3. 4 
IMPOISCURE iorccacccsessicessssuscuececaseieserescerisceceeoss 4.60 4.38 4.69 5.76 
Volatile combustible matter ...... ........c0000 38.36 icin 35.62 36.72 
Hixedicarbomicciccccs.ucssss scene cacwseccesrsesemeetee: Peo Pisco BG agi 
sl peed iden aed Dts ate | se | a 
ho ia ae 
Stl phan s.ctenc. veovesenecscrcetsecsesse eset 2.02 3.07 1.01 0.69 
The California mine is seen to come up to the first rank as to 
quality. All of the samples here reported were taken from the bank 
cars, and represent considerable portions of the mines as now worked. 
Other portions may of course show somewhat different results. 
The Block coal is no longer largely used as an iron-smelting fuel, 
having been almost entirely displaced by Connellsville coke within the 
last 10 years throughout the Mahoning Valley. The low rate at which 
the Pennsylvania coke is now furnished, together with the essential 
advantages that coke has over raw coal in iron manufacture, has led to 
this substitution. The Block coal pays a high royalty, and cannot be 
mined as cheaply as most of the other seams of Ohio and Western 
Pennsylvania. 
In the Cleveland market the Mahoning Valley coal retains its old 
advantage, commanding, with the other coals of the same horizon, at 
least 50 cents more per ton than any other bituminous coal that is 
brought there. 
The present condition of the field in Trumbull county can be made 
out from the following brief notes. In Hubbard township a large part 
of the possible area of the Block coal has already been mined out, and 
