These, and a thousand other anxious speculations crowded my brain.
The tension was so great that I felt that something was on the point of snapping and that I should go mad.
Arising, I again commenced to pace the vault. I found it was about 30ft. wide by almost 20ft. in breadth; near the sides my head sometimes touched the roof; this led me to think that it had been formed out of a natural cavern.
It might be one of a succession of caverns, and divided from others by, perhaps, only a few inches of dirt or stone.
I picked up a large bone and commenced to tap the sides, as I walked round.
After making the circuit of the cave several times, I noticed, that at one corner, the wall had a hollow sound.
I struck it again.
Yes! there could be no doubt the sound was different from that given by other parts.
The hollowness extended for about three feet in each direction.
I felt reanimated, and set to work with the bone to try and pierce the wall.
The bone was too short, and I had to tear part of the earth, near the hole, away, to let me get my arm in.