The Professor was getting excited according to his wont, and was allowing his imagination to run away with him.
"Axel, we are on the way towards the grand discovery. This blade has been left on the strand for from one to three hundred years, and has blunted its edge upon the rocks that fringe this subterranean sea!"
"But it has not come alone. It has not twisted itself out of shape; some one has been here before us!
"Yes--a man has."
"And who was that man?"
"A man who has engraved his name somewhere with that dagger. That man wanted once more to mark the way to the centre of the earth. Let us look about: look about!"
And, wonderfully interested, we peered all along the high wall, peeping into every fissure which might open out into a gallery.
And so we arrived at a place where the s
