The Underground City | Page 7

pudding-stone, schist, compact or friable sandstone, gravel and stones, the whole of the
massive forests.

And what went on in this gigantic crucible, where all this vegetable matter had
accumulated, sunk to various depths? A regular chemical operation, a sort of distillation.
All the carbon contained in these vegetables had agglomerated, and little by little coal
was forming under the double influence of enormous pressure and the high temperature
maintained by the internal fires, at this time so close to it.
Thus there was one kingdom substituted for another in this slow but irresistible reaction.
The vegetable was transformed into a mineral. Plants which had lived the vegeta-tive life
in all the vigor of first creation became petrified. Some of the substances enclosed in this
vast herbal left their impression on the other more rapidly mineralized products, which
pressed them as an hydraulic press of incalculable power would have done.
Thus also shells, zoophytes, star-fish, polypi, spirifores, even fish and lizards brought by
the water, left on the yet soft coal their exact likeness, "admirably taken off."
Pressure seems to have played a considerable part in the formation of carboniferous strata.
In fact, it is to its degree of power that are due the different sorts of coal, of which
industry makes use. Thus in the lowest layers of the coal ground appears the anthracite,
which, being almost destitute of volatile matter, contains the greatest quantity of carbon.
In the higher beds are found, on the contrary, lignite and fossil wood, substances in which
the quantity of carbon is infinitely less. Between these two beds, according to the degree
of pressure to which they have been subjected, are found veins of graphite and rich or
poor coal. It may be asserted that it is for want of sufficient pressure that beds of peaty
bog have not been completely changed into coal. So then, the origin of coal mines, in
whatever part of the globe they have been discovered, is this: the absorption through the
terrestrial crust of the great forests of the geological period; then, the mineralization of
the vegetables obtained in the course of time, under the influence of pressure and heat,
and under the action of carbonic acid.
Now, at the time when the events related in this story took place, some of the most
important mines of the Scottish coal beds had been exhausted by too rapid working. In
the region which extends between Edinburgh and Glasgow, for a distance of ten or
twelve miles, lay the Aberfoyle colliery, of which the engineer, James Starr, had so long
directed the works. For ten years these mines had been abandoned. No new seams had
been discovered, although the soundings had been carried to a depth of fifteen hundred or
even of two thousand feet, and when James Starr had retired, it was with the full
conviction that even the smallest vein had been completely exhausted.
Under these circumstances, it was plain that the discovery of a new seam of coal would
be an important event. Could Simon Ford's communication relate to a fact of this nature?
This question James Starr could not cease asking himself. Was he called to make
conquest of another corner of these rich treasure fields? Fain would he hope it was so.
The second letter had for an instant checked his speculations on this subject, but now he
thought of that letter no longer. Besides, the son of the old overman was there, waiting at
the appointed rendezvous. The anonymous letter was therefore worth nothing.

The moment the engineer set foot on the platform at the end of his journey, the young
man advanced towards him.
"Are you Harry Ford?" asked the engineer quickly.
"Yes, Mr. Starr."
"I should not have known you, my lad. Of course in ten years you have become a man!"
"I knew you directly, sir," replied the young miner, cap in hand. "You have not changed.
You look just as you did when you bade us good-by in the Dochart pit. I haven't forgotten
that day."
"Put on your cap, Harry," said the engineer. "It's pouring, and politeness needn't make
you catch cold."
"Shall we take shelter anywhere, Mr. Starr?" asked young Ford.
"No, Harry. The weather is settled. It will rain all day, and I am in a hurry. Let us go on."
"I am at your orders," replied Harry.
"Tell me, Harry, is your father well?"
"Very well, Mr. Starr."
"And your mother?"
"She is well, too."
"Was it your father who wrote telling me to come to the Yarrow shaft?"
"No, it was I."
"Then did Simon Ford send me a second letter to contradict the first?" asked the engineer
quickly.
"No, Mr. Starr," answered the young miner.
"Very well," said Starr, without speaking of the anonymous letter.