k, then held it up. Harry was about
to take the pen when Tom Reade drawled:

"It wouldn't be quite right for us to sign this report, Don Luis."

"Why not?" queried the Mexican, wheeling like a flash.

"Just for the simple reason," Reade answered, "that to sign the
report would be to state all the facts contained in the report
as being of our personal observation. We haven't seen enough
of the mine, as yet, for it to be right for us to sign the report.
An engineer's signature to a report is his statement--ON HONOR--that
he personally knows such report to be true. So I am very certain
you will understand that it would be a breach of honor for us to
sign this document."

"Ah! He is clever--and now the real trouble must begin!" Dr.
Tisco told himself. "These engineers are not easily duped, but
in Don Luis's hands they will destroy themselves!"

CHAPTER VI

WATCHING THE MIDNIGHT LIGHTS

Don Luis Montez laid down the pen. Outwardly he was as amiable as
ever; certainly he was all smiles.

"A thousand pardons, _caballeros_!" he murmured. "Of course, you
are quite right. It had not occurred to me in that light before.
True, the report was intended only for my own pleasure in later
years, but that does not alter the nice point of honor."

Tom Reade was deceived by Don Luis's manner. He did not suspect
that, at this very instant, the Mexican was consumed with demoniacal
rage.

"I shall not be patient another time," muttered Don Luis, between
his teeth and under his breath. Yet aloud he said:

"We have had too much of business to-day. We are tiring ourselves.
Until dinner time let us go outside and be gentlemen. Business
for to-morrow or next week. And my dear daughter. Brute! I
have been forgetting her."

Senorita Francesca, a darkly beautiful girl of eighteen, shy and
retiring from the convent schooling that had ended but lately,
soon came downstairs at her father's summons. Dr. Tisco bowed
low before the charming girl. Tom and Harry were presented, and
tried to make themselves agreeable to the young Mexican girl.
Senorita Francesca's shyness, however, made this somewhat difficult,
so the young engineers felt inwardly grateful when Dr. Tisco strolled
down the porch with her.

Dinner proved to be a somewhat formal affair. Yet, as soon as
the meal was finished Senorita Francesca was escorted from the
dining room by her father and returned to her room.

"What did you think of the young