as slackening, also that
the shaft grew more narrow, till at length there were only a few feet
between the edge of the stone and its walls. The result of this, or so
I supposed, was that the compressed air acted as a buffer, lessening our
momentum, till at length the huge stone moved but very slowly.

"Be ready to follow me," cried Yva again, and we rose to our feet, that
is, Bickley and I did, but poor Bastin was semi-comatose. The stone
stopped and Yva sprang from it to a rock platform level with which it
lay. We followed, dragging Bastin between us. As we did so something hit
me gently on the head. It was Bastin's lamp, which I seized.

"We are safe. Sit down and rest," said Yva, leading us a few paces away.

We obeyed and presently by the dim light saw the stone begin to stir
again, this time upwards. In another twenty seconds it was away on its
never-ending journey.

"Does it always go on like that?" said Bastin, sitting up and staring
after it.

"Tens of thousands of years ago it was journeying thus, and tens of
thousands of years hence it will still be journeying, or so I think,"
she replied. "Why not, since the strength of the draught never changes
and there is nothing to wear it except the air?"

Somehow the vision of this huge stone, first loosed and set in motion by
heaven knows what agency, travelling from aeon to aeon up and down
that shaft in obedience to some law I did not understand, impressed my
imagination like a nightmare. Indeed I often dream of it to this day.

I looked about me. We were in some cavernous place that could be but
dimly seen, for here the light that flowed down the shaft from the
upper caves where it was mysteriously created, scarcely shone, and often
indeed was entirely cut off, when the ever-journeying stone was in the
narrowest parts of the passage. I could see, however, that this cavern
stretched away both to right and left of us, while I felt that from
the left, as we sat facing the shaft, there drew down a strong blast of
fresh air which suggested that somewhere, however far away, it must open
on to the upper world. For the rest its bottom and walls seemed to be
smooth as though they had been planed in the past ages by the action of
cosmic forces. Bickley noticed this the first and pointed it out to me.
We had little time to observe, however, for presently Yva said:

"If you are rested, friends, I pray you light those lamps of yours,
since we must walk a while in darknes