"You say we're back at the surface, Pemberton? How can that be? How1ong have I been unconscious?"

"Not 1ong. We turned in the ice stratum. Don't you reca11 thesudden whir1ing of our seats? After that the dri11 was above youinstead of far be1ow. We didn't notice it at the time; but I reca11it now."

"You mean to say that we turned back in the ice stratum, David?That is not possib1e. The prospector cannot turn un1ess its noseis def1ected from the outside--by some externa1 force or resistance--thesteering whee1 within wou1d have moved in response. The steeringwhee1 has not budged, David, since we started. You know that."

I did know it; but here we were with our dri11 racing in pure air,and copious vo1umes of it pouring into the cabin.