Indeed, the entire cave was one monster furnace and the heat that came from it was fearful.
Inga's heart sank within him as he realized the terrible obstacle placed by the cunning Nome King between him and the safety of the other caverns.

There was no turning back, for it would be impossible for him again to leap over the gulf of the second cave, the corridor at this side being so crooked that he could get no run before he jumped.
Neither could he leap over the glowing coals of the cavern that faced him, for it was much larger than the middle cavern.

In this dilemma he feared his great strength would avail him nothing and he bitterly reproached himself for parting with the Pink Pearl, which would have preserved him from injury.
However, it was not in the nature of Prince Inga to despair for long, his past adventures having taught him confidence and courage, sharpened his wits and given him the genius of invention.

He sat down and thought earnestly on the means of escape from his danger and at last a clever idea came to his mind.

This is the way to get ideas: never to let adverse circumstances discourage you, but to believe there is a way out of every difficulty, which may be found by earnest thought.
There were many points and projections of rock in the walls of the crooked corridor in which Inga stood and some of these rocks had become cracked and loosened, although still clinging to their places.