round?" asked Harry, of the servant.

"The learned doctor must be dressing by this time, _caballero_,"
replied the servant respectfully.

"Hm!" mused Harry. "Can it be that the people in Bonista do their
work at night?"

"Oh, I'll wager the poor _peons_ at the mine have been at work
for some time," Tom smiled. "Anyway, I'm glad we haven't kept
everyone else waiting."

At half-past ten o'clock Dr. Tisco appeared, immaculate in white.
He bowed low and courteously to the guests.

"I trust, _caballeros_, that you have enjoyed perfect rest."

"Yes," answered Harry. "And now we're fidgeting to get at work.
But, of course, we can't start for the mine until Don Luis gives
us the word, and we are at his pleasure."

"It is nearly time for Don Luis to appear," said Tisco gravely.

"Is he always as late as this?"

"Here, Senor Hazelton, we do not call eleven o'clock a late hour
for appearing."

Twenty minutes later Don Luis appeared, clad in white and indolently
puffing at a Mexican cigarette.

"You will smoke, gentlemen?" inquired their host, courteously, after
he had inquired concerning their rest.

"Thank you," Tom responded, pleasantly. "We have never used tobacco."

Don Luis rang and a servant appeared.

"Have one of my cars ordered," commanded Don Luis.

Ten minutes later a car rolled around to the entrance.

"You will come with us, Carlos?" inquired Don Luis.

"Assuredly, Don Luis," replied the secretary, in the tone of a man
who was saying that he would not for worlds miss an expected treat.

It was a seven-passenger car of late design. Into the tonneau
stepped the two Mexicans and the two young engineers.

"To the mines," ordered Don Luis.

"Do you wish speed, excellency?" inquired the chauffeur.

"No; we will go slowly. We may wish to talk."

Gravely, in military fashion, the chauffeur saluted, then allowed
the automobile to roll slowly away.

"It is not an attractive road, after we leave the _hacienda_,"
explained Don Luis Montez to Tom. "It is a dusty road, and a
somewhat hard one. The mining country is not a beautiful place
in which to live."

"It is at least more beautiful than the country in which our mine
is located," Tom replied.

"Are you gentlemen, then, mine owners as well as mine experts?"
inquired their host.

Tom told Don Luis briefly about their mine, the Ambition, in the
Indian Smoke Range, Nevada.

"And is your mine a profitable one?" inquired the Mexican.

"It