the surface, so that not only do the miners have to go down
into the sulphurous heat, but the caldrons in which the sulphur is
refined give out gases that are unendurable to human throats and lungs.
In our mines, the sulphur is now refined sixty or a hundred feet below
the surface of the ground, and pours out in an already purified state,
at the top of the well."

Sansevero looked incredulous. "But sulphur is almost impossible to
liquefy. Unlike metals, it congeals again when it has been heated beyond
the proper temperature. Also it corrodes any metal it touches, so that a
pipe would be eaten away immediately."

"To get over those difficulties is exactly what I am trying to do by my
new process," Derby answered. "The sulphur is melted by hot water sent
down the pipes, followed by sand, and then sawdust--the sand to carry
the heat to the cooler edges, and the wet sawdust to check the heat at
the center."

Even the princess drew nearer and laid her hand on her husband's arm as
Derby made his explanation. Sansevero trembled with excitement. "But
according to that," he cried, turning to his wife; "our mine would be
practicable!" Then to Derby: "I ought to explain to you that we have a
sulphur mine in Sicily, near Vencata. So far as I know, the sulphur
does, as you say, lie in a bed some twenty meters down. Above it are
rock and alluvial soil. The volcanic neighborhood makes the temperature
below ground higher than can be borne, yet we know that the sulphur
deposit is immense."

"Give me more details. From what you say, it sounds as though this mine
of yours might be exactly what we are looking for. Does Mr. Randolph
know of it, or that you are the owner?"

"No; no one knows it excepting one small group of sulphur owners. I
unwisely went into it on the advice of--some one who is very good at
all these things; yet the best are liable to mistake. Other mines in the
neighborhood, owned by friends of mine, have brought in a fortune. Ours
has, so far, been a failure."

The talk lasted until luncheon was served. Giovanni put in an
appearance, and Derby was pressed to stay. As di Valdo and the American
met, there was a barely perceptible coldness under the Italian's good
manners, while Derby's greeting showed a momentary curiosity. Two more
sharply contrasted beings could hardly have been brought together. But
gradually Giovanni also became interested in the mining plans, and, as
the reason for the American's coming to Euro