Ohio Natural Gas Fields. — Boivnocker. 225 
Berea grit, top at 888 feet, 
bottom at 942 " 
730 feet of 8yi inch casing. 
942 feet of 6J4 iiich casing. 
Corniferous Lower Helderberg and 
Niagara limestones, top at 1735 " 
bottom at 2390 " 
Clinton, top at 2390 " 
bottom at 2460 
Medina, hard above, but very soft below, top at 2460 " 
2554 feet of 5 Vio inch casing. bottom 2560 " 
Cincinnati series, top at 2560 " 
bottom of well 2860 " 
In the Sugar Grove territory the great limestones (Corn- 
iferous, Lower Helderberg and Niagara) are charged with 
salt-water, which sometimes completely fills the well. The 
formation is unbroken, except in the lower fifty feet, where it 
becomes shaly, so that the transition to the Clinton is not 
abrupt, and yet it is easily recognized by the driller. 
Lastly, there is given a skeleton record of a well on the 
Dunlap farm near Homer in Burlington towmship, Licking 
county. 
Drive pipe (8 inch) ■ 307 feet. 
Berea grit, bottom at - 556 " 
566 feet of 65^ inch casing. 
Corniferous, Lower Helderberg and 
Niagara limestones, top at 1310 " 
bottom 2074 " 
Pink limestone and shales, top at 2074 " 
bottom 2187 " 
Clinton sand, top at 2187 " 
bottom 2216 " 
Bottom of well at 2222 " 
The most interesting feature of this part of the field in 
comparison with that around Sugar Grove is the absence of 
water below the Berea grit. As shown in the record just given 
only one string of casing is used, and that extends merely to 
the base of the Berea. This greatly diminishes the cost of the 
wells, and also the chances of water forcing its way down into 
the gas sand. 
The Clinton formation. — This outcrops in the southwestern 
corner of the state. Its area there is very small, forming a 
mere band around the Cincinnati series, but owing to a 
tendency to form an escarpment with the underlying formation 
