GEOLOGY OF OHIO. 109 
Beaver and at Salineville, the latter town taking its name from this fact, 
but the cheapness with which salt has been produced in Michigan and 
New York has caused most of the salt works of northern Ohioto become — 
unprofitable, and, as a consequence, many of them have been abandoned. 
A similar cause has limited the production of hydraulic cement. That 
made at New Lisbon is reported upon favorably by those who have used 
it, and the condition of the old locks of the Sandy and Beaver Canal, 
which were laid up with it, prove that it is a strong and durable cement; 
but the Lake markets are supplied in such abundance and so cheaply 
from western New York, and the region bordering the Ohio, from Barnes- 
ville, Belmont county, and Louisville, Kentucky, that the sales of cement 
made here have been, and probably will continue to be, much restricted. 
In the cliff opposite the town of New Lisbon a section of nearly one 
hundred feet of rock is exposed. Here the blue limestone lies a few feet 
above the creek, and Coal No. 3 is seen under it, thinner than on the 
north side of the valley. Above is a mass of black shale, twenty feet in 
thickness, containing some iron ore, and apparently representing Coal No. 
4. In this shale are large numbers of fossil mollusks (Solenemya radiata) ; 
it is regularly stratified, and is evidently an aqueous deposit. We have 
here an interesting exhibition of the changes which sometimes take 
place in coal seams. Coal No. 4 is the seam known as the Strip Vein at 
Hammondsville and Linton, the upper seam cut in the Salem Shaft, and 
the coal worked at Albany and Leetonia. In all these localities it is a 
remarkably pure.coking coal. Further north, however, in Canfield and 
Berlin townships, Mahoning county, it is a very variable seam, some- 
times becoming cannel throughout, and from five to six feet in thickness; 
sometimes half cannel and half cubical coal, and about four feet thick; 
oftener still, a seam of bituminous coal, two and a half feet thick, with 
six to ten inches of cannel at the top. In passing from Green Village to 
New Lisbon, this coal is seen to diminish in thickness, while the associ- 
ated shale becomes thicker and more bituminous, until, finally, as I have 
stated, the coal is entirely lost, the carbonaceous matter being distribu- 
ted through a sufficient amount of earthy sediment to form nearly twenty 
feet of bituminous shale. 
At Elktou,,below/-New Lisbon; this black shale contains a foot of bitu- 
minoug edak im its lower part: i Jeuriamiles further down the creek, on the 
Wlhems fanm,ithe-coal.seam has.ineréasecdto three and one half feet in 
thickness, with: another!foot of-eoah fine fees NG it. Below it Coal No. 
Soe as thani two feetumothiokwess! vd shsi. 
- asMidwayopfithe clifgsepposite the sane es eyo Coal No. 5 is 
ah bud-isokere quite thins; -Hasdounden both sides of, the valley in 
