"We could, but it might not be safe. I don't want to take on too much weight, as my glider isn't as stable as the airship. But we have plenty of the metal. "Indeed we have," agreed Ivan Petrofsky. "Much of mine and my brother's will go toward helping relieve the sufferings of the Siberian exiles," he added. "And mine, too," said Alexis Borious. They started back early the next morning in a more terrific gale than in any the glider had yet flown. But she proved herself a stanch craft, and soon they were at the place where they had left the airship. It was undisturbed. Four days were spent in taking apart the glider and packing it on board the Falcon. Then, with the platinum safely stored away Tom, with a last look at the desolate land that had been so kind to them, sent his craft on her homeward way. It was when they were near the city of Pirtchina, on the Obi river, that what might have proved a disastrous accident occurred. They were flying along high, and at great speed, for Tom wanted to make all the distance he could, to get out of Siberia the more quickly. They had had a fair passage so far, and were congratulating themselves that they would soon be in civilization again. Suddenly, Mr. Damon, who had been on the after deck, taking observations through a telescope, came running forward, crying out: "Tom! Tom! What is that water dripping from the back part of the airship?" "Water?" exclaimed Tom. "No water is dripping from there." "Come and look," advised Mr. Damon. The young inventor raced back with him. He saw a thin, white stream trickling down from the lower part of the craft. Tom sniffed the air suspiciously. "Gasolene! It's gasolene!" he cried. "We must have a leak in the supply tanks!" He dashed toward the reserve storeroom, and at that moment, with a suddenness that was startling, the motor stopped and the Falcon lurched toward the earth. CHAPTER XXV HOMEWARD BOUND--CONCLUSION "All right!" yelled Ned, as soon as he heard Tom's cry. "I've got her under control. We'll volplane down." "Is it dangerous? Are we in danger?" asked Peter Petrofsky of his brother, in Russian. "I guess there's no danger, where Tom Swift's concerned," was the answer. "I have not volplaned much, but it will be all right I think." And it was, for with Ned Newton to guide the craft, while Tom did his best to stop the leak, the craft came gently to earth on the outskirts of a fairly large Siberian city. Almost instantly the Falcon was surrounded by a curious throng. "You had better keep inside," said Ivan Petrofsky to his brother and Mr. Borious. "Descriptions of you are probably out broadcast by now, but I am still sufficiently disguised, I think." "But what is to be done?" demanded the younger Russian brother. "If the gasolene is gone, how can we leave here?" "Trust Tom Swift for that," was the reply. "Keep out of sight now, there is a large crowd outside." Tom came from the tank room. There was a despondent look on his face.