Part I. Report of progress in 1869, by J. S. Newberry, chief geologist. Part II. Report of progress in the second district, by E. B. Andrews, assist. geologist. Part III. Report on geology of Montgomery County, by Edward Orton, assist. geologist.

33
more than 100,000,000 tons, and a very short calculation will suffice to
show what an important contribution this makes to her national wealth.
The power developed in the combustion of a pound of coal, is reckoned
by engineers as equal to 1,500,000 foot-pounds. The power exerted by a
man of ordinary strength during a day of labor is about the same; so
that a pound of coal may be regarded as equivalent to a day's labor of a
man. Hence three hundred pounds will represent the labor of a man
for a year. It has been estimated that 20,000,000 tons of the annual coal product of Great Britain is devoted to the development of
motive power, and that this is equivalent to the labor of 133,000,000 of
men. These men, in this calculation, are considered as exerting merely,"brute force;" but since they may all be regarded as producers only,
and not consumers-the profit on the balance of her coal product fully
covering all expenses-we are safe in estimating the contribution made
to the wealth of Great Britain, by her annual coal product, as equal to,
that of 133,000,000 of skilled operatives laboring for her enrichment.
Such being the value to a nation or community of this combustible,
let us see how our nation and our State has shared in nature's gifts.
The area of the coal fields of the carboniferous age, lying within the
limits of the United States, has been estimated at 150,000 square miles.
The productive coal area of Ohio is not less than 10,000 square miles, or
quite equal to that possessed by Great Britain, and far in excess of that
of any other European nation.
I have said that the annual coal production of Great Britain is over
100,000,000 tons-a rate of expenditure of capital which is seriously
alarming British economists. In Ohio the annual coal production is now
about 3,000,000 tons. So it will be seen that we not only have an almost
inexhaustible source of wealth in our coal fields, but that as yet we have
scarcely begun to draw from this treasury. Hence I was justified in
saying, as I did, that this promised to be by far the most important
source of our power and material progress; and one of the most important duties pressing upon our legislators, and on us as geologists, is, by
all means in our power, to promote the rapid and intelligent development
of all the industries that are to spring from this source.
In order that we may more clearly apprehend the nature and capabili-.
ties of the material which has such potency, and with which~we are so
richly endowed, I will briefly describe some of the varieties which it
exhibits, and the uses to which they are adapted.
Coal is now considered by all chemists and geologists of any standing
as of organic origin, and it may be easily demonstrated that it has been
derived from the decomposition of vegetable tissue. As we findjit in
the earth, it forms one of a series of carbonaceous minerals whichjrepre.
sent but different stages in a progressive change from vegetable tissue
3-G. S.