The Pittsburg Coal Bed, — WJiite. 55 
to the Ohio river this "breast" division thins and in the 
Glendale and Moundsville shafts is only 21 inches, accord- 
ing to Mr. J. W. Paul, state mining inspector for West Vir- 
ginia. It is still perfectly distinct, however, with the twin 
slates one-fourth of an inch thick each, and enclosing six 
inches of "bearing in" coal immediately below. 
. The "bearing-in" coal is so named by the Monongahela 
river miner, because in mining operations the under-cutting 
of the "breast" coal is made in this layer, the latter being 
then wedged or blown down, and the "brick" division subse- 
quently taken up. The "bearing-in" coal is usually brilliant 
and pure, varying in thickness from three to six inches, and 
enclosed by two thin parting slates, so much alike in color 
and structure as to be almost indistinguishable. Their color 
is usually a dark, mottled gray, and they vary in thickness 
from one-fourth to one inch. The persistency of these twin 
slates over all the regions drained by the Monongahela and 
east to the Georges Creek and North Potomac field, while 
westward to Wheeling, Bellaire and the neighboring regions 
of Ohio they still appear to be present, is one of the remark- 
able features of this coal-bed. When, however, the areas of 
this coal south of the little Kanawha river in West Virginia, 
and west from the Muskingum in Ohio, are examined, these 
twin slates are not fovmd, or if represented are no longer 
recognizable as the Monongahela partings, but the "roof" 
coals and "over-clay" appear to be present. 
The "l)rick" coal comes next under the lower of the twin 
slates, and was so named by the Monongahela river miners 
because it comes out in oblong, rectangular blocks resem- 
bling the shape of common bricks. It is usually about one 
foot thick. The parting which separates the "brick" coal 
from the next lower member is always present along the 
Monongahela from Brownsville to Pittsburg, and it is also 
represented in the Georges Creek and North Potomac field, 
but in the Fairmont region it is only occasionally present, 
the bed there being generally undivided below the ''bearing- 
in" coal. 
The "bottom" member is from twelve to twenty inches 
thick along the Monongahela, and contains so many thin, 
.slaty, sulphurous laminse, that it is usually not taken out in 
