I shuddered at the thought of being lost in the mazes of this vast subterranean labyrinth.
Besides, if the ascending road did become steeper, I was comforted with the thought that it was bringing us nearer to the surface.

There was hope in this.

Every step confirmed me in it, and I was rejoicing at the thought of meeting my little Graeuben again.
By mid-day there was a change in the appearance of this wall of the gallery.

I noticed it by a diminution of the amount of light reflected from the sides; solid rock was appearing in the place of the lava coating.

The mass was composed of inclined and sometimes vertical strata.