“All depends how difficult it is to reach. The newest Neufeldt-Kuhnke rigid diving-suit, armour-plated in cast steel, could just about make it. I doubt if any diver could accomplish anything at that depth. He’d be under a pressure of two hundred pounds to the square inch and any movement would be like in a barrel of heavy tar. Anything except the simplest maneuver would be beyond him. The way to do it would be with observation turrets — Gaieazzi and my old firm, Siebe-Gorman, produce the best — and use those. They can go down about one thousand five hundred feet. You get inside one of those and use a phone to guide laying of explosives or dredgers or grapnels or power grabs. That’s the way they took over ten million dollars’ worth of gold from the Niagara, from about the same depth, off New Zealand, and about four million dollars’ worth of gold from the Egypt, lying in four hundred feet off Ushant. Those are the two classic cases of modern times and that’s how I would do it”
“And of course that would require at least a couple of surface vessels and much specialised equipment,” Vyland said softly. “Do you think we can go around buying up observation turrets — if there are any available in this country — and dredgers and then sit anchored in the same spot for weeks without exciting suspicion?”
“You have a point,” I admitted.
“So the bathyscaphe,” Vyland smiled. “The valley in the sea floor is less than six hundred yards from here. We take with us grabs and hooks attached to wires on drams fastened to the outside of the scaphe, fix them on — you can do some very fancy work with those extension arms and grabs fitted in front — then come back here, unreeling the wire as we go. Then we haul the wire in from the X 13.”
“As easy as that, eh?”
“Just as easy as that, Talbot. Clever, you would say?”
“Very.” I didn’t think it clever at all, I didn’t think Vyland had even begun to appreciate the difficulties involved, the endless slow-motion try, try, try again frustration of underwater salvage, the scope of the initial preparation, the skill and experience of years required. I tried to remember how long it had taken to salvage two and a half million dollars’ worth of gold and silver from the Laurentic, sunk in only just over a hundred feet of water — something like six years if I remembered rightly. And Vyland spoke as if he was going to do it in an afternoon. “And where exactly is the scaphe?” I asked.
Vyland pointed at the semi-circular trunking. “That’s one of the support legs of this rig — but it happens to be raised twenty feet above the sea bed. The bathyscaphe is moored below that.”
“Moored below it?” I stared at him. “What do you mean? It’s beneath the bottom of that leg? How did you get it there? How do you get into it? How in the world
“Simple,” he interrupted: “I am not, as you may have gathered, much of an engineer but I do have an — ah — professional friend who is. He devised the simple expedient of fitting a reinforced and completely waterproof steel floor of great strength across the bottom of this leg — about six feet from the bottom, actually — and letting into this a tapering steel cylinder about six feet long and not quite three feet in diameter, projecting downwards, open top and bottom, but the top capable of being sealed off flush with the waterproof floor by a screwed hatch. In a recession about two feet from the top of this cylinder is a reinforced rubber tube. . . . You begin to see daylight, I think, Talbot?”
“I see daylight.” They were an ingenious bunch, if nothing else. “Somehow — almost certainly at night — you got the rig’s engineers to co-operate with you in the lowering of this leg — I suppose you told them the yarn about top secret research, so secret that no one was allowed to see what was going on. You had the bathyscaphe on the surface, unbolted its bridge cover, lowered the leg slowly until this cylinder fitted over the bathyscaphe’s entrance hatch, pumped this rubber ring full of compressed air to make a perfect seal, then lowered the leg into the water, pushing the bathyscaphe down before it while someone inside the bathyscaphe, probably your engineering friend, adjusted the hydrostatic valve for one of the adjacent flooding chambers enough to let it sink easily but not so much as to rob it of its slight positive buoyancy necessary to keep the top of the entrance chamber jammed into the cylinder at the foot of the leg. And when you want to take off you just climb into the bathyscaphe, seal both the cylinder and bathyscaphe hatches, have someone on the rig blow the air from the rubber seal gripping the entrance chamber of the bathyscaphe, flood your tanks to get enough negative buoyancy to drop clear of the leg and there you are. Reverse process when you come back except that you’ll need a suction pump to clear the water that’s accumulated in the cylinder. Right?”
“In every detail.” Vyland permitted himself one of his rare smiles. “Brilliant, you might call it?”
“No. The only brilliant thing was stealing the bathyscaphe. The rest is within the scope of any moderately competent underwater operator. Just an application of the double-chambered submarine rescue diving bell which can fit in much the same way over the escape hatch of practically any submarine. And a fairly similar principle has been used for caisson work — sinking underwater piers for bridges and the like. But smart enough for all that. Your engineer friend was no fool. ,A pity about him, wasn’t it?”
“A pity?” Vyland was no longer smiling.
“Yes. He’s dead isn’t he?”
The room became very still. After perhaps ten seconds Vyland said very quietly: “What did you say?”
“I said he was dead. When anyone in your employ dies suddenly, Vyland, I would say it was because he had outlived his usefulness. But with your treasure unrecovered, he obviously hadn’t. There was an accident.”
Another long pause. “What makes you think there was an accident?”
“And he was an elderly man, wasn’t he, Vyland?”
“What makes you think there was an accident?” A soft menace in every word. Larry was licking his lips again.
“The waterproof floor you had put in in the bottom of the pillar was not quite as waterproof as you had thought. It leaked, didn’t it, Vyland? Only a very small hole, possibly, and in the perimeter of the floor where it joined the side of the leg. Bad welding. But you were lucky. Somewhere above where we’re standing there must be another transverse seal in the leg — to give structural strength, no doubt. So you used this machine here ” — I pointed to one of the generators bolted to the deck — ” to drive in compressed air after you’d sent someone inside the leg and sealed this door off. When you’d driven in enough compressed air the accumulated water was driven out the bottom and then the man — or men — inside were able to repair the hole. Right, Vyland?”
“Right.” He was on balance again, and there was no harm in admitting something to a person who would never live to repeat it to anyone. “How do you know all this, Talbot?”
“That footman up in the general’s house. I’ve seen many cases. He’s suffering from what used to be called caisson disease — and hell never recover from it. The diver’s bends, Vyland. When people are working under a high ak or sea pressure and that pressure is released too quickly they get nitrogen bubbles in the blood. Those men in the leg were working in about four atmospheres, about sixty pounds to the square inch. If they’d been down there more than half an hour they should have spent at least half an hour decompressing, but as it was some criminal idiot released the built-up pressure far too fast — as fast as it could escape, probably. At the best of times caisson work, or its equivalent, is only for fit young men. Your engineer friend Was no longer a fit young man. And you had, of course, no decompressor. So he died. The footman may live Song enough but he’ll never again know what a pain-free existence is. But I don’t suppose that troubles you, does it, Vyland?”
“We’re wasting time.” I could see the relief on Vyland’s face, for a moment there he’d suspected that I — and possibly others as well — knew too much about the happenings on the X 13. But he was satisfied now — and very relieved. But I wasn’t interested in his expression, only in the general’s.