"No doubt there is plenty of ice and snow in winter; but just here there seems to be nothing but swamps and forests."

"And swarms of mosquitoes," added Birger. "Don't forget the mosquitoes!"

In a moment more the children were back in their seats, and the train was creeping slowly northward, on its way toward Gellivare and Mount Dundret, where, from the fifth of June to the eleventh of July, the sun may be seen shining all day and all night.

Birger took a tiny stone from his pocket and showed it to his sister, saying, "See my souvenir of Polcirkel." But Gerda paid little attention to his souvenir, and slipped over to her father's seat to ask a question.

"Father," she said softly.

Lieutenant Ekman looked up from the maps and papers in his lap. "What do you wish, little daughter?" he asked.

"Will you please make me a promise?" she begged.

"If it won't take all my money to keep it," he answered with a smile.

But Gerda seemed in no hurry to tell what it was that she wanted, and began looking over the papers in his lap. "What is this?" she asked, taking up a small blue card.

"That is my receipt from the Tourist Agency," he answered. "When I give it to the station master at Gellivare, he will give me a key which will open the hut on Mount Dundret, and let us see the midnight sun in comfort."

"How much did you pay for it?" was Gerda's next question.

"I paid about four kronor for the card and all the privileges that go with it," was the answer.

"Have you plenty of money left?" asked the little girl.

Her father laughed. "Enough to get us all three back to Stockholm, at least," he said. "Why do you ask?"

"Because--" said Gerda slowly, and then stopped.

"Because what?" Lieutenant Ekman asked again.

"Because I wondered if we could stop at the lighthouse on our way home and ask Karen Kla.s.son to go to Stockholm and live with us;" and Gerda held her breath and waited for her father to speak.

"Perhaps she would not like to leave her father and mother for the sake of living with us," he said at last.

"I think she would, if it would make her back well," persisted Gerda.

Herr Ekman laughed. "If living with us would cure people's backs, we might have all the lame children in Sweden to care for," he said.

"But I want only Karen," said Gerda; "and I thought it would be good for her to take the Swedish medical gymnastics at the Inst.i.tute in Stockholm, where so many people are cured every year."

Lieutenant Ekman looked thoughtfully at his daughter. "That is a good idea and shows a loving heart," he said. "But are you willing to give up any of your pleasures in order to make it possible?"

Gerda looked at him in surprise, and he continued, "I am not a rich man.

If we should take Karen into our family and send her to the gymnasium, it would cost a good many kronor, and your mother and I would have to make some sacrifices. Are you willing to make some, too?"

Gerda gazed thoughtfully across the stretches of bog-land to the forest on the horizon. "Yes," she said at last; "I will go without the furs Mother promised to buy for me next winter."

Lieutenant Ekman knew well that Gerda had set her heart on the furs, and that it would be a real sacrifice for her to give them up; but if she were willing to do so cheerfully, it meant that she was in earnest about helping her new friend.

"Yes," he said, after a moment; "if you will give up the furs, we will see what can be done. On the way home we will stop at the lighthouse and ask Hans Kla.s.son to lend Karen to us for a little while."

Gerda clapped her hands. "Oh, a promise! A promise!" she cried joyously.

"What a good souvenir of Polcirkel!" and she ran to tell Birger the news.

CHAPTER VI

THE MIDNIGHT SUN

"What time is it, Father?" asked Gerda, as they reached the top of Mount Dundret, and Lieutenant Ekman took the key out of his pocket to open the door of the Tourists' Hut.

"It is half past eleven," replied her father, looking at his watch.

"At noon or at night?" questioned Gerda.

"Look at the sun, and don't ask such foolish questions," Birger told her.

"When the sun is high up in the heavens it is noon; but when it is down on the horizon it is night."

Gerda looked off at the sun which hung like a huge red moon on the northern horizon. "Then I suppose it is almost midnight," she said, "and time to go to bed. I was wishing it was nearer noon and dinner-time."

"You'll have to wait for dinner-time and bedtime, too, until we get back to Gellivare," her father told her.

"When you have travelled so far just to see the sun shining at midnight, you should spend all your time looking at it," said Birger, opening his camera to take some pictures.

Gerda looked down into the valleys below, where a thick mist hung over the lakes and rivers; then turned her eyes toward the sun, which was becoming paler and paler, its golden glow shedding a drowsy light over the hills.

"How still it is!" she said softly. "All the world seems to have gone to sleep in the midst of sunshine."

"It is exactly midnight," said her father, looking at the watch which he had been holding in his hand.

Birger closed his camera and slipped it into his pocket. "There," he said, "I have a picture of the sun shining at midnight, to prove to Oscar that it really does shine. Now I am going to gather some flowers to press for Mother;" and he ran off down the side of the hill.

Gerda found a seat on a rock beside the hut, and sat down to watch the beginning of the new day. The sun gradually brightened and became a magnificent red, tinging the clouds with gold and crimson, and gilding the distant hills. A fresh breeze sprang up, the swallows in their nests under the eaves of the hut twittered softly,--all nature seemed to be awake again.

"I've been thinking," said Gerda, after a long silence, "that I told Hilma I should understand about the midnight sun if I should see it; but I'm afraid I don't understand it, after all."

"It is this way," Lieutenant Ekman began. "The earth moves around the sun once every year, and turns on its own axis once every twenty-four hours."

"That is in our geography," Gerda interrupted. "The path which the earth takes in its trip around the sun is called its...o...b..t. The axis is a straight line that pa.s.ses through the center of the earth, from the North Pole to the South Pole."

"That is right," said her father; "and if old Mother Earth went whirling round and round with her axis perpendicular to her orbit, we should have twelve hours of daylight and twelve hours of darkness all over the earth every day in the year."

"I suppose she gets dizzy, spinning around so fast, and finds it hard to stand straight up and down," suggested Gerda.