A hasty exploration revealed the fact that but a single shaft had
remained intact. A third time we prepared our electrical machinery. We
let down a cable and succeeded in getting but a faint reaction at the
bottom of the shaft. After several repeated clearings we risked descent.

Upon arrival at the bottom we were surprised to find it free from water,
save for a trickling stream. The second thing we discovered was a pile
of huddled skeletons of the workmen who had perished over a century
previous. But our third and most important discovery was a boring from
which the poisonous gas was slowly issuing. It took but a few hours to
provide an apparatus to fire this gas as fast as it issued, and the
potash mines of Stassfurt were regained for the world.

My associates were for beginning mining operations at once, but I had
been granted a twenty years' franchise on the output of these mines, and
I was in no such haste. The boring from which this poisonous vapour
issued was clearly man-made; moreover I alone knew the formula of that
gas and had convinced myself once for all as to its man-made origin. I
sent for microphones and with their aid speedily detected the sound of
machinery in other workings beneath.

It is easy now to see that I erred in risking my own life as I did
without the precaution of confiding the secret of my discovery to
others. But those were days of feverish excitement. Impulsively I
decided to make the first attack on the Germans as a private enterprise
and then call for military aid. I had my own equipment of poisonous
bombs and my sapping and mining experts determined that the German
workings were but eighty metres beneath us. Hastily, among the crumbling
skeletons, we set up our electrical boring machinery and began sinking a
one-metre shaft towards the nearest sound.