“Let’s have another crack at it!” cried Tom, and went to work with the spade again.

In ten minutes he had scattered considerable earth and made the hole much larger.  They held the lantern inside and saw that the floor of the other cavity was about on a level with the one in which they stood.  Tom slid the old spade through the hole, and then went through himself.

“Come on! let’s take a look,” he said, reaching up for Ruth and the lantern.

“But this isn’t finding a way out,” complained Ralph.  “What will the other folks say?”

“We’ll find the opening later.  We couldn’t venture outside now, anyway.  It is still storming, you can bet,” declared the eager Tom.

Ruth’s sharp eyes were peering here and there.  The cavern they had entered was almost circular and had a dome-shaped roof.  There were shelves all around several feet above the floor.  Some of these ledges slanted inward toward the rock, and one could not see much of them.

“Lift me up here, Tom!” commanded the girl.  “I want to scramble up on the ledge.”

“You’ll hurt yourself.”

“Nonsense!  Can’t I climb a tree almost as well as Ann Hicks?”

He gave her a lift and Ruth scrambled over the edge with a little squeal.

“Oh, oh, oh!” she cried.  “Here’s something.”

“Must be,” grunted Tom, trying to climb up himself.  “Why, I declare, Ruthie! that’s a box.”

“It’s a little chest.  It’s ironbound, too.  My! how heavy.  I can’t lift it.”

“Tumble it down and let’s see,” commanded Ralph, holding the lantern.

Ruth sat down suddenly and looked at the boys.

“I don’t know,” she said.  “I don’t know that we’ve got any right to touch it.  It’s padlocked.  Maybe it is old Mr. Tilton’s treasure-box.”

“That would be great!” cried Tom.

“But I don’t know,” continued Ruth, reflectively.  “We would better not touch it.  I wouldn’t undertake to advise Jerry what to do if he found it.  But this is what they call ‘treasure trove,’ I guess.  At least, it was what that Rufus Blent had in mind, all right, when he sold Mr. Tingley the island with the peculiar reservation clause in the deed.”

CHAPTER XXIV

A MIDNIGHT MARAUDER

Meanwhile the boys and girls left behind in Jerry Sheming’s old camp began to find the absence of Ruth and her two companions rather trying.  The time which had elapsed since the three explorers started to find the eastern outlet of the cave seemed much longer to those around the campfire than to the trio themselves.

Before the searching party could have reached the brookside, had the tunnel been perfectly straight, the nervous Belle Tingley wanted to send out a relief expedition.

“We never should have allowed Ruthie to go,” she wailed.  “We all should have kept together.  How do we know but they’ll find the cave a regular labyrinth, and get lost in it, and wander around and around, and never find their way out, or back, and——­”