“Maybe I can pry the door open with this,” he said. “Luck seems to be coming my way after all.” The bar was heavy, but Larry strained at it until he had inserted the wedge-like edge in the crack between the door and the side of the air lock. “Here goes!” he exclaimed. He pressed on the bar with all his strength. It did not budge. “I guess it’s tighter than I thought,” gasped the boy. Once again he pushed until his arms trembled with the strain. Again and again, throwing himself forward, he forced the bar away from him. Then, just when he was ready to give up in despair, he felt the iron lever give slightly. So little was the movement he half doubted whether it had moved. But as he pressed harder and harder he felt it sway, and then he knew he had started the door to swinging. “I must keep at it!” he panted, “or it will get stuck again.” Then with all his strength he pushed until, in the half-light, he saw the crack opening wider and wider until the door was half open and there was space enough for him to slip through. “Hurrah!” cried Larry faintly. “Now to see if the other door is open,” for the air lock had two portals. He dragged the bar with him as he stooped to go through the small opening. The air lock was about ten feet long, constructed entirely of steel and iron, and was about as big around as a hoisting engine boiler. Larry had to bend almost double as he went through it. Fortunately he found the other door open, and a few seconds later he was out in the tunnel again. “Now for a telephone,” he cried as he sprang forward on the run. Just ahead he could see a big patch of light that indicated where the round shaft led from the surface of the earth down to the floor of the tunnel. The going was easier now and the air was better. Larry soon reached the foot of the shaft. He found a number of workmen there. They were covered with dirt and water and Larry knew they had been working in the tunnel. “Where’d ye come from, boy?” asked one of them. “I was with the party that went through a little while ago,” Larry answered. “One of the men sent me back for something.” He did not say what it was, for fear some of the men might not think it proper for him to telephone the news to his paper. “Want to go up?” asked the man in charge of the elevator. Larry nodded. The man motioned for him to get on the movable platform which was about all the hoist was, and then gave the signal to start. In a few moments the boy was at the surface. He made his way out of the engine room at the mouth of the upright shaft and hurried across the railroad yards in the direction he had come. On the way in he had noticed an office where there was a telephone and he made for this. The man in charge gave permission for the boy to use the instrument, though he stared somewhat in surprise at Larry, who was covered with dirt and water. “Fall in the river?” he asked. “No, I came through the tunnel,” replied the boy.