"Down that ladder there.

You'll be able to see the furnaces and the stokers at work.

I don't believe you'll care to go into the stoke-hole." Frank descended.

Great heat came up to him, accompanied by a glow that shifted and changed, dying down suddenly at one moment and glaring out at the next.

He could hear the ring of shovels and the clank of iron doors.
He reached an iron grating, where a fierce heat rolled up and seemed to scorch him.