687 
of every geologist and scientific engineer ; a thing compiled 
from sinkings here and borings there, possibly tolerably 
correct for a very limited district, but representing as fairly 
the measures of the whole coal-field, as the single brick 
represented the house out of which it was taken. For 
instance, take the coal known as the High Hazles or Kent's 
Thick; about Sheffield it is a good coal, four feet thick; 
utterly worthless about Barnsley ; and again workable, but 
only 2' 6", at Mapplewell. How can a " General Section " 
show this? The history of almost every other bed of coal 
in the field will prove in the same way the worthlessness of 
"General Sections." 
All that I complain of is easily explained ; the information 
is not likely to be of value for many a long day, at least we 
hope so ; and posterity is left to take care of itself. But I 
would venture to suggest that coal, to which England owes 
her great commercial prosperity, and which when once gone 
can never be replaced, is being used by us at an enormous 
rate ; in short, that we are living on our capital : and this 
being the case, the barest justice demands that we should 
hand down to those who come after us the records of our 
experience, to enable them to turn to the best account the 
comparatively trifling remnant that we have left unconsumed. 
These few remarks, I hope, will be taken in good part, and 
will not be held to argue any want of gratitude on my part 
for the favours and kind attentions which I have everywhere 
received, and for which any thanks that I can offer must be 
a most inadequate return. 
But I am not here to lecture on the ethics of coal-mining, 
and will at once turn to my subject. 
The lowest of the thick workable coals in this part of the 
field is the Silkstone, Sheffield, or Black Shale Coal, a " soft " 
or bituminous bed of great purity, yielding excellent house- 
coal, and well suited for coking. It consists of two beds, 
