300 GEOLOGY OF OHIO. 
Recasting this section, and omitting all but the coals, and also pre- 
fixing the Middle Kittanning coal, as in the previous arrangement, we 
find the order shown below: 
Middle Kittanning coal. 
Titer vial ios. hoki e8e ac ches Cede Sedbesbateedecs cabes Saescncolteccc con muee ent 100 feet. 
First coal seam. 
WNGervall:..: ccs cess vosescasevesbesteccsseneeveceuseetesocseconereesueceeeeeeeene 73 feet. 
Second coal seam. 
Intervaltss, coc. iisesteccccssecsseetens wacudes eBanssharecsseeteceteees beens dh 32 feet. 
Norris coal. 
There is no hint in the drillers’ record of any limestone or other 
characteristic element, except the coals. We are thus left quite un- 
certain as to the equivalence of these elements in the general section. 
Were it not for the presence of the two limestones named in the first 
table, in territory so near the Norris farm, a more satisfactory identifica- 
tion of the coal seams would appear to be found in referring the Norris 
seam to the Lower Mercer horizon, the second coal to the Upper Mercer 
horizon, and the first coal to the Brookville seam. This would make 
theyintervals abnormal in the way of increase, very much as the other 
scheme renders them abnormal by reduction. 
_ A definite answer cannot therefore be given at this time as to the 
place in the series to which the coal of the Post Boy. boring belongs. 
As between the two references suggested, the latter would seem to have 
most reasonable support in the facts of the general section, and the 
former in the facts of the particular section. 
The?Lower Coal Measures, as developed in the remaining counties 
of the Ohio coal field, will be discussed in subsequent chapters. 
