"It means land being washed away by water. If you put a piece of land
in the water, the water will dissolve it and it won't take long either.
It isn't like an island that has always been where it is--a kind of
hill sticking up out of the water. This is just a piece of land and
the roots of this little tree won't hold it together long.

"The question is, should we go hunting for new members under those
conditions? Pretty soon we'll have a full patrol and no island under
us; we'll be in the water. That's perfectly agreeable to me and all
the rest of us. But does Keekie Joe know how to swim? We really have
no _grounds_ for forming a patrol. See?"

"Do you call that an argument?" Pee-wee thundered. "It shows how much
you know about geography because look at an ice cream soda! Does that
corrode? Let's hear you answer that? Or erode or whatever you call
it. A chunk of ice cream floats in the soda, doesn't it? Maybe after
a while it melts, but this land isn't ice cream, is it?

"That shows how much you know about logic. This island has been here
ever since early this morning, hasn't it? And it's just as big as it
was, isn't it? An island is an island and the water won't melt it
unless it's hot--like a lump of sugar in a cup of coffee. You've got
to stir it up to melt it. Is North America corroding? Or Coney
Island? Is this island any smaller than it was?"

"No, it isn't, and that's the funny part," said Townsend. "We've
explored the coast but we haven't explored the depths. Let's have that
little shovel a minute, will you?"