"Maybe the roots hold it together," said Roland.

"It ought to dissolve," said Townsend. "This land doesn't seem to be soluble in water. The coast all around ought to wash away. There is something mysterious here. This island is as solid as a pancake; I don't understand it. By all the rules of the game there shouldn't be anything left here but the tree by this evening. There doesn't seem to be any process of erosion."

"What will we do if the island washes away from under us?" asked the boy they called Brownie. "The tree'll fall over sideways, won't it? I don't want to camp on an island that keeps getting smaller all the time. It's bad enough to have a tent shrink after a rain, but an island!"

"I think this island is warranted not to shrink," said Townsend.

"Warranted nothing," said Billy; "look how muddy the water is all around it. It'll be about as big as a fifty cent piece by midnight. The river is eating it all away."

"Speaking of eating," said Townsend, "here comes the discoverer."

The discoverer and his companion were indeed approaching and apparently they had sacked the town of Bridgeboro. Their gallant barque labored under a veritable mountain of miscellaneous paraphernalia and out of the pile projected a long bar with a device on the end of it which glinted red and green in the sunshine.

"It looks like a weather-vane," said Billy.

"There's something printed on it," said Roly.

"It says STOP," said the boy they called Nuts.