13 
person found out the only place where the coal is well shown, 
and sunk a pit, hut finding' the coal worthless, he has gone a 
little way off on the old red sandstone, where ho is sinking after 
the most approved manner, bricking his shaft round. lie is 
going through some very hard sandstone.” In this case the 
true explanation, of course gratuitously offered, was disregarded, 
and the last report announced by the “ practical men ” was, 
that they were on the very verge of discovering coal. 
Observe in the vertical column, and in this horizontal section, 
the geological position of the lower silurian shales, utterly barren 
of coal, and sunk thousands upon thousands of feet beneath the 
coal measures, carboniferous limestone, and old red sand- 
stone.* They are often black, and carbonaceous-looking, and 
their oozing springs are sometimes discoloured and scummy by 
the presence of oxide of iron, and other impurities derived in the 
passage of the water through the rocks. But coal measure 
shales are also frequently black, carbonaceous, and charged with 
numerous beds of ironstone, which, discolouring the springs, 
produce the red water (dwr goch) of the Welsh miner. By a 
mistaken application of the principle, that like causes produce 
like effects, the empirical miner sets to work, and the black 
slates of the counties of Pembroke, Radnor, and Caermarthen, 
— of Montgomery, Merioneth, and Caernarvon, — near Trefgarn, 
Caermarthen, Builth, Llanidloes, in Lleyn, and at Caernarvon, 
— are dotted with shafts, borings, and levels, sunk or driven in 
delusive searches for coal. While in progress, the cry still is, 
“ the indications are good, go a little deeper and the pit, the 
disappointment, and the ruin, often deepen together, till, aban- 
doned in despair, the speculator is left to console himself with 
the parting assurance, “ We are not to blame ; — had you only 
gone a little deeper.” Long after, when the wandering geologist 
visits such spots, he is informed that the miners actually found 
coal, but were bribed to hush it up by coal owners jealous of 
their markets. 
I do not wish to imply that the men who advise such under- 
* Alluding to diagrams on the wall. 
