"I won't tease you， then， old Simon，" answered James Starr. "Far be it from me even in jest to depreciate the New Aberfoyle mine by an unjust comparison！ I only meant to say one thing， and that is that we don't know where we are."

"We are in the subsoil of the county of Stirling， Mr. Starr，" replied Simon Ford； "and that I assert as if--"

"Listen！" said Harry， interrupting the old man.

All listened， as the young miner was doing. His ears， which were very sharp， had caught a dull sound， like a distant murmur.

His companions were not long in hearing it themselves.

It was above their heads， a sort of rolling sound， in which though it was so feeble， the successive CRESCENDO and DIMINUENDO could be distinctly heard.

All four stood for some minutes， their ears on the stretch， without uttering a word. All at once Simon Ford exclaimed， "Well， I declare！ Are trucks already running on the rails of New Aberfoyle？"

"Father，" replied Harry， "it sounds to me just like the noise made by waves rolling on the sea shore."

"We can't be under the sea though！" cried the old overman.

"No，" said the engineer， "but it is not impossible that we should be under Loch Katrine."

"The roof cannot have much thickness just here， if the noise of the water is perceptible."

"Very little indeed，" answered James Starr， "and that is the reason this cavern is so huge."

"You must be right， Mr. Starr，" said Harry.

"Besides， the weather is so bad outside，" resumed Starr， "that the waters of the loch must be as rough as those of the Firth of Forth."

"Well！ what does it matter after all？" returned Simon Ford；"the seam won't be any the worse because it is under a loch.

It would not be the first time that coal has been looked for under the very bed of the ocean！ When we have to work under the bottom of the Caledonian Canal， where will be the harm？"

"Well said， Simon，" cried the engineer， who could not restrain a smile at the overman's enthusiasm； "let us cut our trenches under the waters of the sea！ Let us bore the bed of the Atlantic like a strainer； let us with our picks join our brethren of the United States through the subsoil of the ocean！ let us dig into the center of the globe if necessary， to tear out the last scrap of coal."

"Are you joking， Mr. Starr？" asked Ford， with a pleased but slightly suspicious look.

"I joking， old man？ no！ but you are so enthusiastic that you carry me away into the regions of impossibility！ Come， let us return to the reality， which is sufficiently beautiful； leave our picks here， where we may find them another day， and let's take the road back to the cottage."

Nothing more could be done for the time. Later， the engineer， accompanied by a brigade of miners， supplied with lamps and all necessary tools， would r閟um？the exploration of New Aberfoyle. It was now time to return to the Dochart pit.

The road was easy， the gallery running nearly straight through the rock up to the orifice opened by the dynamite， so there was no fear of their losing themselves.

But as James Starr was proceeding towards the gallery Simon Ford stopped him.

"Mr. Starr，" said he， "you see this immense cavern， this subterranean lake， whose waters bathe this strand at our feet？

Well！ it is to this place I mean to change my dwelling， here I will build a new cottage， and if some brave fellows will follow my example， before a year is over there will be one town more inside old England."

James Starr， smiling approval of Ford's plans， pressed his hand， and all three， preceding Madge， re-entered the gallery， on their way back to the Dochart pit. For the first mile no incident occurred.

Harry walked first， holding his lamp above his head.

He carefully followed the principal gallery， without ever turning aside into the narrow tunnels which radiated to the right and left.