1008 GEOLOGY OF OHIO. 
Summary. 
The coal supply of Vinton county is peculiar in this respect, 
viz., that it is largely derived from seams that are seldom worked or 
workable elsewhere. The Tionesta, Brookville and Clarion (Upper) 
coals have greater volume than any other seams of the county, while 
of the Kittanning and Freeport coals, though all are present, but 
one is mined to any extent. This one yields but little more than 3 
feet of marketable coal, but it is characterized by persistency and 
steadiness, as well as by good quality, and therefore becomes a safe 
basis of large mining enterprises. 
MINES OF JACKSON CouNTY. 
It is to be regretted that time has not sufficed for working out the 
lowermost 200 feet of the coal measures of Southern Ohio, and 
particularly of Jackson county, in such a way that clear and satisfac- 
tory statements could be made as to the order of the geological elements 
of economic interest comprised in this part of the seale. Although 
-a good deal of work has been done in th district since the date of 
Professor Andrews’s report upon it in 1870, many of the questions un- 
settled at that time remain unsettled still. What is required is a few 
weeks’ work carried on in a methodical way, and with the aid of in- 
strumental measurements upon the lower coals of the county. Until 
this is done, it is scarcely worth while to advance statements upon the 
disputed points which, resting largely on individual judgment, can be 
offset by the different conclusions of other observers. 
These lower coals constitute the chief element in the mineral 
wealth of the county, at the present time, and their superior develop- 
ment here gives to Jackson county an enviable pre-eminence among 
the Coal Measure counties of this part of the State. 
Almost all of those whose judgment in regard to the question 
is entitled to respect, consider the Jackson Shaft coal and the Wellston 
coal as two distinct seams, but now and then an intelligent person is 
found who still maintains the older view, that the two coals belong to 
the same horizon. | 
There is, of course, no instance known in which typical and 
universally accepted representatives of these coals are found in the 
same vertical section, for in such a case the question could not be 
raised, but a few localities can be pointed out in which the fields 
