"Guess we'll have to dig some more," said Bob.
"Wait a minute. Let me get a purchase on it with the bar."
Laurie seized that implement again and drove it into the softened earth beside the post. As the first drive didn't send it far enough, he pulled it out, and put all his strength into the next effort. This time he succeeded beyond all expectations. The bar slipped through his fingers and disappeared from sight!
"Where-where did it go to?" cried Bob, dumfounded.
"It went--it went to China, I guess! It just slipped right through my hands, and kept on slipping!" Laurie knelt and dug at the hole with his fingers.
"No, I can't feel it. Hand it here." Laurie took the shovel and dug frantically. Then Bob dug. The result was that they enlarged and deepened the hole around the post, but the crowbar failed to materialize.
"I suppose," said Laurie, finally, dropping the shovel and tilting back his cap, "what happened was that I struck a sort of hole, and the bar went right down in. Maybe it was a rat-hole, Bob."
"I guess so. Anyway, it's gone, and we'll have to get a new one."
"Oh, I guess we'll find it when we get the post out. Let's try the old thing."
They did, and, after a moment of indecision, it came out most obligingly. But there was still no crowbar to be seen. Laurie shook his head, mystified. "That's the funniest thing I ever saw," he declared.
"It surely is! Look here; maybe there's an old well there."
"Then why didn't the post go down into it?"
"Because it's covered over with stones. The bar happened to slip into a--a crevice."
Laurie nodded dubiously. "That might be it," he agreed. "Or perhaps we've discovered a subterranean cavern!"
"Caverns always are subterranean, aren't they?"
"No; sometimes they're in the side of a hill."
"A cave and a cavern are the same thing, you smart Aleck."
"All right; but even if a cavern is in a hill, it's underground, and subterranean means under--"
"Help! You win, Bob! Come on and get hold of this log and let's get it out of here." And, as they staggered with it across the garden to add it to the pile of posts and lumber already there, he continued: "There's one thing certain, Bob, and that's that you won't get me to play tennis on your court. I'd be afraid of sinking into the ground some fine day!"