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.

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Bituminous Coal. Loss. Anthracit6.
Carbon.-.... 18.10 - 3.57 = 14.53
Hydrogen.........,20 - 0.93 027
Oxygen.-........ 2.07 - 1.32 = 0.65
Anthracite. Loss. Plumbago.
Carbon....... 14.53 1.42 = 13.1 t
Hydrogen......... 0 27 - 0.14 = 0.13
Oxygen.....-. 0.65 - 0.65 0.0
From this table it will be seen that the change from wood-tissue to
peat or lignite, and from these to bituminous, thence to anthracite coal
and plumbago, consists in the evolution of a portion of the carbon, hydrogen and oxygen, leaving a constantly increasing percentage of carbon
behind, until ultimately the resulting mineral consists of a portion of the
original carbon of the plant with all its earthy matter. That portion of
the original substance which is lost in this progressive change, escapes
in the form of some hydrocarbon, as water, carburetted hydrogen, carbonic acid, petroleum, &c. The escape of these volatile compounds we
see in the gases bubbling up from marshes where vegetable matter is
undergoing decomposition; in the gases generated in.our coal mines
and, in my judgment, in our oil-springs, which always flow from strata
charged with bituminous matter. By the application of heat, and with
proper management, we can manufacture any of these mineral fuels from
vegetable fibre at will. This has been done repeatedly, and although we
cannot accurately reproduce the conditions under which these changes
are effected in nature's laboratory, we can so closely imitate them as to
demonstrate their character.
We find also that, under peculiar circumstances, nature has departed
from her usual routine, and has locally effected all the changes I have
enumerated, in a short space of time; as at Santa Fe, New Mexico,
where a trap dyke has cut through Cretaceous strata in which are beds
of soft and nearly valueless lignite, and where over a large area this outflow of melted rock has converted this lignite into a compact and valuable anthracite. So at Los Bronces, in Sonora, Triassic coals are converted into anthracite by the eruption of porphyritic rock. On Queen
Charlotte's Island, south of Alaska, is a Tertiary lignite changed by a
similar cause into the most beautiful and brilliant anthracite I have ever
seen.
All the coals of Ohio belong to the group known as bituminous coals,
but these exhibit very considerable variety in their chemical and physical characters, and the different varieties are adapted to very different
uses.
Following an economic classification, our coals may be described as,
first, dry, open-burning or furnace coals; second, cementing or coking
coals; third, cannel coals.