after all, I do remember one other thing besides the purely personal affair, which is, that a sort of gutter came presently across the floor of the cavern, and then ran along by the side of the path of rock we followed. And it was full of that same bright blue luminous stuff that flowed out of the great machine. I walked close beside it, and I can testify it radiated not a particle of heat. It was brightly shining, and yet it was neither warmer nor colder than anything else in the cavern.
Clang, clang, clang, we passed right under the thumping levers of another vast machine, and so came at last to a wide tunnel, in which we could even hear the pad, pad, of our shoeless feet, and which, save for the trickling thread of blue to the right of us, was quite unlit. The shadows made gigantic travesties of our shapes and those of the Selenites on the irregular wall and roof of the tunnel. Ever and again crystals in the walls of the tunnel scintillated like gems, ever and again the tunnel expanded into a stalactitic cavern, or gave off branches that vanished into darkness.
We seemed to be marching down that tunnel for a long time. "Trickle, trickle," went the flowing light very softly, and our footfalls and their echoes made an irregular paddle, paddle.