322 COAL-FIELDS OF KENTUCKY. 
ing of iron. This coal has been worked in various 
places, and is now delivered at Chilicothe at 16 
cents a bushel, of which many thousand bushels 
are annually consumed. 
The thickness of these three beds of coal ranges 
from 10 to 17 feet. " The whole amount of coal," 
says Mr. Briggs, "between the Ohio River and the 
Hocking Valley, may be safely estimated as suffi- 
cient to form an entire stratum 50 miles in length, 
five miles in width, and nine feet in thickness. This 
amount of coal will yield about 9,000,000 of tons 
per square mile. This estimate includes but a very 
small part of the coal which can be obtained from 
the beds heretofore described ; for, after disappear- 
ing beneath the water-courses, they doubtless con- 
tinue eastward towards the Ohio River, sinking 
deeper and deeper beneath the surface, so that they 
can be reached only by shafts near the Ohio at the 
depth of some hundred feet. The method of ob- 
taining coal by sinking shafts has not yet been 
practised in this country to any considerable ex- 
tent, but will ultimately be in Ohio, when the con- 
sumption of fossil coal shall have created a suffi- 
cient demand for the article. Shafts have been 
sunk with success, under the direction of practical 
geologists in Great Britain, to the depth of 1200 to 
1500 feet. Coal must undoubtedly be obtained in 
this way in our own country at no very remote pe- 
riod."* 
COAL' FIELDS IN KENTUCKY. 
Extensive beds of coal are found along the base 
of the Cumberland Mountains, stretching along 120 
miles west of them, in the heads of Licking, Ken- 
tucky, Green, and Cumberland rivers. Throughout 
this region, embracing the sides and spurs of Cum- 
berland Mountains, the prevailing rock is sand- 
stone ; on its western limit it changes to limestonCi 
* Eeport to the Legislature of Ohio, 1838, p. 87, 
