fi. B. Andrews—Parallelism of Coal-seams. 57 
opinion, while he strenuously maintains the latter. In my 
district, and in the portions of his district—i. e., the one under his 
special supervision—that I have examined, and also in the bor- 
dering States of West Virginia and Kentucky, I find a general 
useful in our Coal-measures. If, on the other hand, the subsi- 
ence were uneven and irregular, no coal-seam can have its 
proper and exact horizon, and all things are in confusion. If, 
for example—and I quote one of the cases given by Dr. New- 
berry in his article—coals No. 8 and No. 9 are, at one place, 150 
feet apart, and have three coal seams, 8a, 82 and 8c, intercalated 
between them, and a few miles away they are only 50 feet apart, 
with no intercalated seams, the mind is left in confusion and 
perplexity, and the practical identification of coal-seams is well 
nigh impossible. The theory of unequal subsidences, of “ very 
local subsidences,” of “ warped and folded strata,” is itself very 
confusing, for it requires us to believe that the old shore-areas 
held themselves in statical equilibrium near the water’s edge 
during the long periods in which the vegetable matter of the 
face, with the coal-swamps filling its basins and winding hol- 
lows, subsided below the ocean, the introduction of the proper 
Coal-measure stratification began, and then occur horizon- 
tally arranged sediments, Hence, the next seam of coal 
