"The Vikings had no such easy way as this of getting from Lake Mälar out into the Baltic Sea," said Lieutenant Ekman, coming up to find the children, and helping himself generously to the kringlor. Gerda looked at the gnarled and sturdy oaks that lined the banks of the canal like watchful sentinels. "The Vikings must have loved the lakes and bays of the Northland," she said. "Perhaps they begged All-father Odin to let their spirits come back and make their homes in these trees." "No doubt they did," replied her father, gravely enough. "I suppose when the trees wave their arms and shake themselves so violently they are saying to each other something like this: 'See how these good-for-nothing children go in good-for-nothing boats over this good-for-nothing ditch.'" "With their good-for-something father," cried Gerda, throwing her arms around his neck and giving him a loving kiss. "Am I really good for something?" he asked, as soon as he could speak. "Well then, you must be good for something, too. In olden times the Vikings sailed the seas and brought home many a treasure from foreign shores. See that you take home some treasures from your journey,--something that will remind you of the towns we visit and the sights we see," and he put his hand into his pocket and took out three coins. "The Vikings had a fashion of taking what they wanted without paying for it," suggested Birger. "You'd better not try it now, my son," replied Herr Ekman; and he gave each one of the children a krona. "Here's a kringla to remind me of Södertelje," said Gerda, slipping one of the cakes into her pocket; and then the three children went off to the forward deck to watch the boat sail out into the ocean. For fifty miles they sailed among wooded islands and rocky ledges, and then entered the canal which connects the Baltic Sea with Lake Roxen. On the way the boat stopped at two or three ports, and each tune the children went ashore to buy a souvenir. "Show me your treasures, and I will show you mine," Gerda said to Erik, after the first stop. The boy shook his head. "I bought something useful," he said, "and I shall send it to my father;" but even with coaxing he would not tell what it was, until they were all ready to show their treasures to Lieutenant Ekman. So all three of the children agreed to keep their souvenirs a secret, and had great fun slipping off alone to buy them. All day and all night, and all the next day, the boat steamed across the open lakes, glided noiselessly into the quiet canals, or climbed slowly step by step up the locks. Toward night of the second day Birger suddenly announced, "This is Lake Viken, and it is the highest lake on the way between the two ends of the canal route. The captain says that it is more than three hundred feet above the level of the sea." "Have we seen the prettiest part of the route?" asked Gerda.