The Poisoned Pen [58]
tunnel obstructed the narrow passage to such an extent that we had to be careful in picking our way. At last we reached the shield, and on hands and knees we crawled out into one of its compartments. Here we experienced for the first time the weird realisation that only the "air" stood between us and destruction from the tons and tons of sand and water overhead. At some points in the sand we could feel the air escaping, which appeared at the surface of the river overhead in bubbles, indicating to those passing in the river boats just how far each tunnel heading below had proceeded. When the loss of air became too great, I learned, scows would dump hundreds of tons of clay overhead to make an artificial river bed for the shield to stick its nose safely through, for if the river bed became too thin overhead the "air" would blow a hole in it. Capps, it seemed to me, was unusually anxious to have the visit over. At any rate, while Kennedy and Paddy were still crawling about the shield, he stood aside, now and then giving the men an order and apparently forgetful of us. My own curiosity was quickly satisfied, and I sat down on a pile of the segments out of which the successive rings of the tunnel were made. As I sat there waiting for Kennedy, I absently reached into my pocket and pulled out a cigarette and lighted it. It burned amazingly fast, as if it were made of tinder, the reason being the excess of oxygen in the compressed air. I was looking at it in astonishment, when suddenly I felt a blow on my hand. It was Capps. "You chump!" he shouted as he ground the cigarette under his boot. "Don't you know it is dangerous to smoke in compressed air?" "Why, no," I replied, smothering my anger at his manner. "No one said anything about it." "Well, it is dangerous, and Orton's a fool to let greenhorns come in here." "And to whom may it be dangerous?" I heard a voice inquire over my shoulder. It was Kennedy. "To Mr. Jameson or the rest of us?" "Well," answered Capps, "I supposed everybody knew it was reckless, and that he would hurt himself more by one smoke in the air than by a hundred up above. That's all." He turned on Kennedy sullenly, and started to walk back up the tunnel. But I could not help thinking that his manner was anything but solicitude for my own health. I could just barely catch his words over the tunnel telephone some feet away. I thought he said that everything was going along all right and that he was about to start back again. Then he disappeared in the mist of the tube without even nodding a farewell. Kennedy and I remained standing, not far from the outlet of the pipe by which the compressed air was being supplied in the tunnel from the compressors above, in order to keep the pressure up to the constant level necessary. I saw Kennedy give a hurried glance about, as if to note whether any one were looking at us. No one was. With a quick motion he reached down. In his hand was a stout little glass flask with a tight-fitting metal top. For a second he held it near the outlet of the pipe; then he snapped the top shut and slipped it back into his pocket as quickly as he had produced it. Slowly we commenced to retrace our steps to the air-lock, our curiosity satisfied by this glimpse of one of the most remarkable developments of modern engineering. "Where's Paddy?" asked Kennedy, stopping suddenly. "We've forgotten him." "Back there at the shield, I suppose," said I. "Let's whistle and attract his attention. I pursed up my lips, but if I had been whistling for a million dollars I couldn't have done it. Craig laughed. "Walter, you are indeed learning many strange things. You can't whistle in compressed air. I was too chagrined to answer. First it was Capps; now it was my own friend Kennedy chaffing me for my ignorance. I was glad to see Paddy's huge form looming in the semi-darkness. He had seen that we were gone and hurried after us. "Won't ye stay down an' see some more, gintlemen?" he asked. "Or have ye had enough of the air? It seems very smelly to me this mornin' - I don't blame ye.