366 : GEOLOGY OF OHIO. 
Mr. Hirsher, at Findlay, not only manufactures the common red pot- 
tery from clay found in the Drift at that place, but he makes also a supe- 
rior pottery from fire-clay imported from Portage and Summit counties. 
The average product of his establishment is sixteen to eighteen hundred 
gallons per week the year round. The clay in its natural condition is 
subjected to a pug-mill process with a little water, molded by hand, and 
burned with a regular heat for about two days. A glazing is produced 
by pouring over the articles before placing them in the kiln a fine clay 
reduced by water to the consistency of cream, and passing through the 
kiln, while burning, the fumes of common salt. The glazing consists of 
a silicate of sodium, formed by the chemical union of the soda fumes from 
the salt with the silicic acid of the clay, which can only be effected at a 
red heat. | 
A single deposit of bog ore was noted in Hancock county. It occurs 
on the land of Mr. Charles Van Horn, Jr., N. W. } section 7, in the town- 
ship of Amanda. It has been cut by a ditch ten inches below a peat of 
about ten inches. It covers ten acres, more or less. An impure bog ore, 
or an iron ochre, may be often met with along the north slope of the 
ridges which cross the northern portion of the county, and in some 
places a bog ore of average quality could probably be taken out. These 
ochres could be made useful in the manufacture of an umber-colored 
mineral paint. 
Wells and Springs.—W ells on the gravel ridges reach water from eight 
to twenty feet below the surface. In the Drift immediately adjoining 
the ridges they pass through hard-pan a depth of forty to eighty feet 
before obtaining water. Sometimes a shallow artesian well is met with 
along the north slope of the ridges, depending for a supply on the reser- 
voir of water in the gravel of the ridge, and confined by the overlapping 
of the hard pan upon the gravel of the ridge. When the well descends 
to the rock the water is apt to show mineral impurities, as at Findlay, 
where nearly every well is affected with a sulphurous taste. Many of 
these, however, are drilled from ten to fifty feet into the Niagara lime- 
stone underlying. At the same place an inflammable gas which escapes 
from such wells is utilized for purposes of illumination. The residence 
‘of Dr. Jacob Carr is thus lighted. 7 
The following extract from a letter from Dr. Carr, ‘dated February 4, 
1872, covers the various points of interest connected with his well: 
(3 * * * +s 
I have lighted my house during the last nine or ten years from an 
adjoining well, which at first was dug to the rock, seven feet from the surface of the 
ground, for the purpose of procuring water for house use. The gas comes through 
crevices in the rock, and spoils the water for kitchen use. Three such wells are on 
