riment. Derrick and Paul therefore left the mine that evening
without being molested. They took pains, however, not to be very far
behind two brawny pillars of strength in the shape of Tom Evert and Monk
Tooley when they reached the foot of the slope.

Before going home Monk Tooley walked with Derrick to the Widow
Sterling's, to inquire after his boy, and was much pleased to learn that
he was getting along nicely.

"It lightens my heart ter hear yer say dat, missus," he said to Mrs.
Sterling, "an' it's not one woman in ten thousand would do what yer
doin' fer my poor lad."

"Derrick proposed it," said Mrs. Sterling, with a mother's anxiety that
her son should receive all the credit due him. "Without his help I'm
afraid I should not have been able to invite Bill to come here."

"He's a fine lad, missus," replied the miner, "an' if de time ever comes
dat I can serve you or him, my name's not Monk Tooley if I don't jump at
de chance."

After sitting a while with Bill, and doing what lay in his power to make
him comfortable, Derrick again got out his father's plans of the old
workings of the mine, and pored over them intently. Finally he
exclaimed, "It's all right; I am sure of it!"

"What are you so sure of, my son?" asked his mother, looking up from her
work.

"Something I have been trying to find out for Mr. Jones, mother, but he
does not want a word said about it; so I must keep the secret to myself,
at any rate until after I have seen him."

"Seems to me that you and Mr. Jones have a great many secrets together.
You really are becoming quite an important young man, Derrick."

Although Derrick only smiled in reply, he thought to himself that his
mother was about right, and hoped others would take the same view of his
importance that she did.

Selecting some tracing-paper from among the things left by his father,
the boy made a tracing from the plan he had been studying. He followed
all the lines of the original carefully, except in one place where the
plan was so indistinct that he could not tell exactly where they were
intended to go. Being in a hurry, and feeling confident that they should
be continued in a certain direction, he drew them so without verifying
his conclusions.

When he had finished he left the house, and went directly to that of the
mine boss, taking the tracings he had just made with him.

CHAPTER X

IN THE OLD WORKINGS--MISLED BY AN ALTERED LINE

Mr. Jones was expecting Derr