There was no reason for stopping for a whole hour; James Starr, Madge, Harry, and Simon Ford walked on, though there was nothing to show them what was the exact direction of this unknown tunnel.
And they would no doubt have gone farther still, if they had not suddenly come to the end of the wide road which they had followed since their entrance into the mine.
The gallery ended in an enormous cavern, neither the height nor depth of which could be calculated.

At what altitude arched the roof of this excavation--at what distance was its opposite wall--the darkness totally concealed; but by the light of the lamp the explorers could discover that its dome covered a vast extent of still water--pond or lake--whose picturesque rocky banks were lost in obscurity.
"Halt!" exclaimed Ford, stopping suddenly.

"Another step, and perhaps we shall fall into some fathomless pit." "Let us rest awhile, then, my friends," returned the engineer.

"Besides, we ought to be thinking of returning to the cottage." "Our lamp will give light for another ten hours, sir," said Harry.
"Well, let us make a halt," replied Starr; "I confess my legs have need of a rest.

And you, Madge, don't you feel tired after so long a walk ?" "Not over much, Mr.Starr," replied the sturdy Scotchwoman; "we have been accustomed to explore the old Aberfoyle mine for whole days together." "Tired?
nonsense!" interrupted Simon Ford; "Madge could go ten times as far, if necessary.