to describe some of his experiments in raising Spanish mules.
The finest mules that come out of Spain, class, in price, with
blooded horses. Don Luis talked with the enthusiasm of one who
understood and loved mules.

Then, finally, they passed to the office.

"Now, I shall be glad to talk with you for hours," the Mexican
hidalgo assured the young engineers.

Dr. Tisco, as though to show that he took no personal interest in
the talk, retired to an armchair at the further end of the room.
Nevertheless, the secretary observed carefully all that was said.
Covertly he studied the faces of the young engineers at all times.

"Ask me what you will," begged Don Luis, as he sank into an easy
chair close to the table on which Tom began to arrange his envelopes
of specimens taken from the mine.

"First of all, Don Luis," Tom began, "you spoke of some problems
that you wished us to solve in the operation of your mine."

"Yes, Senor Tomaso."

"I would like to ask you what the problems are that we are to
consider," Tom announced.

"Did you not see some of the problems before you, while we were
going through the mine?" inquired Montez.