incoming tide brings salt water up the river from the ocean, the outgoing
tide carries fresh water down from the lake.

Just as the great clock in the church tower began chiming the hour of
nine, a group of children gathered on the granite pier opposite the
King's Palace.

A busy scene greeted their eyes. Vessels were being loaded and unloaded,
passengers were arriving, men were hurrying to and fro, and boys selling
newspapers were rushing about in the crowd.

"Do you see the _North Star_?" Sigrid asked the others. "That is the name
of the boat they are going to take."

"There it is!" cried Oscar; "and there are Gerda and Birger on the deck."
With a merry shout of greeting he ran on board the steam launch, followed
by all the other girls and boys.

"Oh, Gerda, how I wish I were going with you," said Hilma wistfully. "I
should love to cross the Arctic Circle and see the sun shining all night
long."

Gerda, who was wearing a pretty blue travelling dress, with blue ribbons
on her hat and in her hair, threw her arms around her friend. "I wish
you were going, too," she answered. "Birger is the best brother any girl
could have; but he isn't like a sister, and that is what you are to me,
Hilma."

At the same moment, Birger was confiding to his friend, "I wish you were
going with us, Oscar. Gerda is a good sister; but she isn't like a