Another three hours, and I saw no bottom to the chimney yet. When I lifted my head I perceived the gradual contraction of its aperture. Its walls, by a gentle incline, were drawing closer to each other, and it was beginning to grow darker.

Still we kept descending. It seemed to me that the falling stones were meeting with an earlier resistance, and that the concussion gave a more abrupt and deadened sound.

As I had taken care to keep an exact account of our manoeuvres with the rope, which I knew that we had repeated fourteen times, each descent occupying half an hour, the conclusion was easy that we had been seven hours, plus fourteen quarters of rest, making ten hours and a half. We had started at one, it must therefore now be eleven o’clock; and the depth to which we had descended was fourteen times 200 feet, or 2,800 feet.

At this moment I heard the voice of Hans.

“Halt!” he cried.