"No."

"Is the wall made of sheet iron?"

"No; it gives no metallic sound when you hit it."

"Is it of ironwood?"

"No; it isn't iron and it isn't wood."

"What is it then?"

"Impossible to say. But, anyhow, steel doesn't touch it." Uncle
Prudent, in a sudden outburst of fury, began to rave and stamp on the
sonorous planks, while his hands sought to strangle an imaginary
Robur.

"Be calm, Prudent, he calm! You have a try."

Uncle Prudent had a try, but the bowie-knife could do nothing against
a wall which its best blades could not even scratch. The wall seemed
to be made of crystal.

So it became evident that all flight was impracticable except through
the door, and for a time they must resign themselves to their fate--
not a very pleasant thing for the Yankee temperament, and very much
to the disgust of these eminently practical men. But this conclusion
was not arrived at without many objurgations and loud-sounding
phrases hurled at this Robur--who, from what had been seen of him at
the Weldon Institute, was not the sort of man to trouble himself much