The little island was now moving slowly upstream by the incoming tide.
It caught on the flats, performed a slow pirouette like some drowsy
toe-dancer or exhausted merry-go-round, then extricated itself and
floated majestically in the channel till the little apple tree became
involved with the foliage along shore.

"Do you know this seems like a very funny kind of an island to me?"
Townsend Ripley drawled. "I wonder what makes it hold together? It
ought to disintegrate."

"Dis what?" asked Billy.

"Disintegrate--that's Latin for falling to pieces."

"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.