"Let's wait until morning," said his more cautious brother.
Billy stooped down and picked up something. It was a rusty knife, with a few specks of yellow stone.
"What have you got?" asked Frank.
"Someone has been in this cave—years ago I should judge by this rusty knife," said the ranch boy. "And, unless I'm very much mistaken, we've stumbled on the hiding place of the treasure."
"The treasure!" gasped Andy. "What do you mean?"
"I mean this is the most promising sign we've struck yet," went on Billy. "I think these are particles of gold. I can soon tell. Make a fire, so we can see."
One was kindled, and by the light of it the test was applied.
"Gold! It's gold all right!" fairly yelled Billy, as the biting acid did not tarnish the touchstone on which he rubbed the yellow particles. "There's gold in this cave, and this is probably where the old miner found his nuggets, just before he went crazy, and forgot the location of it. Since then the bushes have grown over the mouth of the cavern, and no one stumbled upon it until——"
"Until I stumbled in it!" interrupted Andy, with a laugh. "But if there's gold there let's go in and get it!"
"No," said Billy, after a moment's thought, "it's too late to-night. But we'll come the first thing in the morning, and, if the cave is big enough, we'll camp here instead of in the tent."