Ring of Fire II(31)

Ginny nodded. "Now we will have to persuade Mazalet to do it this way. He had some very strange ideas. Another thing. It will be cold and dark down there. You're going to get wet. You need wetsuits or something that will keep water in to get warm."



"Wool. Wool to the skin," said Olof, whose German was improving as fast as Ginny's Swedish. "Mama always said that."



"Wool, and tight-weave linen over it. With tight cuffs, collars and ankles. Maybe even belts to keep them tight. It will still be cold and miserable."



"It is the job, ja," said Lars. "We Delsbo boys are not afraid of a little cold. Besides they can haul us up quickly to get warm."



"NO. Um. Look, believe me on this . . . Decompression will kill you. You will have to come up slowly. I've got decompression tables."



"She knows what she's talking about, boys," said Per, calmly. "But we can take some dry clothes. The divers can get dry and have a drink when they come out of the water, even if they are in a big barrel. Look at the glass. There is still some room to sit above the water level."



Ginny nodded again. "You will have to take some kind of lantern down there. As long as air keeps coming from the surface, you'll be fine. Look, Mazalet was full of wild ideas about making up-time devices to dive with. I spent a lot of time explaining that the diving bell was simple, relatively easy to make and did not require some kind of non-return valve, because air is lighter than water."



Per held up the glass. "Will this work?" he asked. "The secret is that the air-pipe from the surface must bubble into the water right? Otherwise this, how do say, pressure, will push the air out of the bell. So we attach the pipe to the bottom of the bell, but we drill little holes, here—about one third of the way up from the lip. The water will always go as high as the holes, because the air is only trapped in the upper two thirds of the bell. The bubbling-in air comes in at the bottom. The trapped air can never meet."



Ginny smiled. He was the quickest of the four brothers. "Yes. And you can pump air to a diver with a helmet down a pipe—so long as the air is pumped from the air that is trapped inside the bell, and the diver is working at nearly the same depth. But to be safe if the bell is at ten fathoms, the diver probably should not go more than say another two fathoms to twelve fathoms. So we could pump air to a diver from the surface, but only if he is not more than two fathoms down."



"And what is the use of that?" asked Lars. "We can swim from the surface to two fathoms."



"But if we are at twenty fathoms, we can go to twenty-two—provided the pumping is done from inside the bell," said Olof thoughtfully. "The air is thick in the bell from the heaviness of the water. So the water cannot push it so easily."



It wasn't perhaps a text-book explanation, but he did have some of the idea of pressure, which considering his background was amazing. "Normally, the deeper the diver goes the more risk that the pressure, that heaviness, pushing back air—even the air in his lungs—up the hose to the surface. With the system we are using if the pump fails, only the air inside the hose will flow back because the canvas hose will collapse. And there is no air connection to air in his lungs or the bell. If it sucks anything it will suck water. We'll test the pumps for their ability to push air to various depths, but I have some plans for a simple double cylinder rotary one that ought to work."



She had to start explaining again and drawing pictures.





Fermin Mazalet shook his head. "This is more complex than I thought. The barge, yes. But the barrel? All those iron hoops? And the reinforcing to the top of the thing? It's more like a battering ram than something for going under the sea. And the weight of it . . . I'm not sure we'll get it to work. . . ."



"Look at it from the bright side," Lars quipped. "Even if it doesn't work, our treasure sits in plain sight. We could even lash ourselves to the mainmast if there is a storm."



"Lash ourselves to the mainmast?" Per shook his head. "What would be the point of that?"



"It's the done thing," said Lars, with a seriousness only betrayed by a tiny twitch. "In all the best stories."



Mazalet shook his head in bemusement. The Lennartson brothers were unlike any other Swedes he knew. The common people in Stockholm were a solid and dependable lot. They were not exactly dull, but not given to much frivolity either. His divers were different. They were inventing commercial diving on an ad hoc basis, solving problems at a frightening rate, and with an incongruously off-hand manner. Sometimes they even came up with solutions to problems that Mazalet had not even been aware of. Despite the summer heat, the Frenchman shuddered. Mazalet was honest enough, with himself at least, to realize that his contributions had become increasingly irrelevant. Some of his own half-baked solutions would probably have killed the crew, and Mazalet had come to look forward to Per's explanations with a sort of dreadful fascination. He'd perchance found men who would, if not salvage the bronze cannon, at least make it look very tempting to investors. He swayed between belief and the warm and cozy feel of a good scam coming together. "If you weren't so clever . . . If that piglet you used had not lived for a good twenty minutes beneath the water surface inside the barrel, I would be tempted to have you all committed as madmen."