eathless with excitement. "Then there is a secret
pocket, or poke as your exasperating uncle calls it."

"There must be," said Sinclair; "and now that we know that, we're going
to find it. Of course, we assumed there was one, but we had only that
foolish doggerel to prove it. Now this regular bill establishes it as a
fact beyond all doubt. Do you know this Martin Campbell, Grandy?"

"I know there was a mason by that name, who worked here several times for
your uncle. He came down from Leicester, but of course I know nothing
more of him."

"We'll find him!" declared Bob. "We'll make him give up the secret of the
pocket."

"Maybe he's dead by this time," said Sinclair. "Was he an old man,
Grandy?"

"I don't know, my dear. I never saw him. He worked here when I was away
in London. I fear, however, he is not alive now."

"Oh, perhaps he is. It was only about thirty-five years ago, or forty,
that he built this 'secret pocket.' Thirty-eight, to be exact. The date
on the bill proves that."

"Well, to-morrow you must go to see him," said Mrs. Hartley, rising. "But
now, my children, you must go to bed. You can't learn any more to-night,
and to-morrow we will pick up the broken thread. Patty, my dear child,
you are doing a great deal for us."

"It isn't anything yet," said Patty, "but oh, if it only leads to
something, I shall be so glad!"

CHAPTER XVIII

THE OLD CHIMNEY-PIECE

But Sinclair's search for the old mason in Leicester was absolutely
unsuccessful. He learned that Martin Campbell had died many years ago,
and had left no direct descendants. A cousin of the old mason told
Sinclair all this, and said, too, that there were no books or papers or
accounts of the dead man left in existence.

So Sinclair returned home, disappointed but not entirely discouraged.

"We'll find it yet," he said to Patty. "We have proof of a hiding-place,
now we must discover it."

"We will!" declared Patty. "But it's so exasperating not to know whether
the old mason built that 'pocket' indoors or out."

"Out, I think," said Sinclair. "It's probably a sunken bin or vault of
brick, made water-tight, and carefully concealed."

"Yes, it's certainly carefully concealed," Patty agreed.

Sinclair was entitled to a fortnight's vacation from his law studies, and
he arranged to take it at this time. For now that the interest was
revived, all were eager to make search all the time.

"Let's be systematic about it," said Bob, "and