to the left and walked along a path that ran from the canal
across the green fields to what looked like a hill.

But it wasn't a hill at all, really, because there aren't any
hills in Holland. It was a long, long wall of earth, very high--
oh, as high as a house, or even higher! And it had sloping
sides.

There is such a wall of earth all around the country of Holland,
where the Twins live. There has to be a wall, because the sea is
higher than the land. If there were no walls to shut out the sea,
the whole country would be covered with water; and if that were
so, then there wouldn't be any Holland, or any Holland Twins, or
any story. So you see it was very lucky for the Twins that the
wall was there. They called it a dyke.

Grandfather and Kit and Kat climbed the dyke. When they reached
the top, they sat down a few minutes to rest and look at the
great blue sea. Grandfather sat in the middle, With Kit on one
side, and Kat on the other; and the basket of worms and the
basket of lunch were there, too.

They saw a great ship sail slowly by, making a cloud of smoke.

"Where do the ships go, Grandfather?" asked Kit.

"To America, and England, and China, and all over the world,"
said Grandfather.

"Why?" asked Kat. Kat almost always said "Why?" and when she