"Here are the rails on which they moved the two gigantic pieces which were responsible for the bombardment."
"I say! You can't bombard from the bottom of a cavern! Where are the embrasures?"
"The rails will take us there. Show a good light, Bernard. Look, here's a platform mounted on a pivot. It's a good size, eh? And here's the other platform."
"But the embrasures?"
"In front of you, Bernard."
"That's a wall."
"It's the wall which, together with the rock of the hill, supports the terrace above the Liseron, opposite Corvigny. And two circular breaches were made in the wall and afterwards closed up again. You can see the traces of the closing quite plainly."
Bernard and the lieutenant could not get over their astonishment:
"Why, it's an enormous work!" said the officer.
"Absolutely colossal!" replied Paul. "But don't be too much surprised, my dear fellow. It was begun sixteen or seventeen years ago, to my own knowledge. Besides, as I told you, part of the work was already done, because we are in the lower rooms of the old Ornequin buildings; and, having found them, all they had to do was to arrange them according to the object which they had in view. There is something much more astounding, though!"