towards the apex of its flight and plunged down into a vertical cylinder, forcing this down before it. About it moved the shapes of tenders, little figures that seemed vaguely different from the beings about us. As each of the three dangling arms of the machine plunged down, there was a clank and then a roaring, and out of the top of the vertical cylinder came pouring this incandescent substance that lit the place, and ran over as milk runs over a boiling pot, and dripped luminously into a tank of light below. It was a cold blue light, a sort of phosphorescent glow but infinitely brighter, and from the tanks into which it fell it ran in conduits athwart the cavern.
Thud, thud, thud, thud, came the sweeping arms of this unintelligible apparatus, and the light substance hissed and poured. At first the thing seemed only reasonably large and near to us, and then I saw how exceedingly little the Selenites upon it seemed, and I realised the full immensity of cavern and machine. I looked from this tremendous affair to the faces of the Selenites with a new respect. I stopped, and Cavor stopped, and stared at this thunderous engine.
"But this is stupendous!" I said. "What can it be for?"