SUPPLEMENTAL REPORT—HANGING ROCK DISTRICT. 933 
fied deposits, shales, sandstones, fire-clays, coals, etc., accumulated in 
these separate localities in the vast lapse of years that one hundred 
and eighty feet of strata require for their growth. Equality of moasure 
is not, however, to be inferred for cther portions of the district. In 
Greenfield township, Gallia county, the same interval expands to two 
hundred and twenty feet. Both horizons here are perfectly distinct and 
certain, and the interval was carefully measured with the engineer’s level. 
It will be observed that the whole intervals in the two sections are 
divided in very nearly the same way. Especially a Buff Limestone is 
found in each at a height of about sixty-five feet above the base. _ Mae 
connections of this last named horizon are numerous,.and it seems al- 
most certain that the Buff Limestone of the Hocking Valley is one and 
the same with the Buff Limestone of Monitor Furnace. There are, 
however, several limestones of this general character in this part of the 
series to the northward, and inasmuch as no direct continuity of the 
stratum has been proved, the identification is not positive. 
This steadiness is all the more surprising when the difference of ma- » 
terials that fill the intervals is considered. There are much heavier 
sandstones to the southward than in the Hocking Valley. 
A third section is here introduced that represents with great fidelity 
and minuteness the general stratigraphical order of the series in the 
southern part of Winton and the northern part of Jackson counties. 
This section was furnished by Dr. L. W. Baker, of Hamden Junction, 
to whose untimely death, reference was made in the letter that introduces 
this Report. This section stands for a great amount of labor, and a more 
thorough and accurate knowledge of the field than any other man has 
ever had. The section was made on entirely independent measure- 
ments from those already reported, but it is in substantial agreement 
with them. In regard to the lowermost two hundred feet, it must be 
granted that there is less certainty than in the other portions. This 
part of the series has not yet received the attention that it merits. 
This report will be concluded with the publication of a number of 
chemical analyses that have been made in the laboratories of the Ohio 
State University during the last two years, of the economical minerals of 
the Hanging Rock District. These analyses will be seen to embrace 
many points of interest and importance both as regards quantity and 
quality. They have been made without expense tothe Survey or tothe 
State. The analysis of a few limestones outside of the district is also 
introduced here, because they aré in process of trial as flux among the 
furnaces of the Hocking Valley. All of these analyses were executed by 
Curtis C. Howard, B. S., now Assistant Professor of Chemistry in Star- 
ling Medical College, Columbus. : 
