GEOLOGICAL STUDIES IN SITU

Next day, Tuesday, June 30, at 6 a.m., the descent began again.

We were still following the gallery of lava, a real natural staircase, and as gently sloping as those inclined planes which in some old houses are still found instead of flights of steps. And so we went on until 12.17, the precise moment when we overtook Hans, who had stopped.

"Ah! here we are," exclaimed my uncle, "at the very end of the chimney."

I looked around me. We were standing at the intersection of two roads, both dark and narrow. Which were we to take?