inca.gold-第9节
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e rock passageway like so much meat through a jagged pipe。 〃Stand by。 Give me your depth。〃
〃I read slightly over seventeen meters。 Much higher than the bottom of the sinkhole。 We were sucked into a passage that sloped upward for twenty meters。〃
〃You're borderline；〃 Giordino informed him； 〃but the others have exceeded their time and pressure limits。 I'll pute and advise you of depression stops。〃
〃Don't make them too long。 Once the pony bottle is empty； it won't take long for the three of us to use up what air I have left in my twin tanks。〃
〃Perish the thought。 If I don't hold these kids by the collar； they'll jerk you out of there so fast you'll feel like you were fired from a cannonball。〃
〃Try to keep it civilized。〃
Giordino held up his hand as a signal for the students to begin pulling。 〃Here we go。〃
〃Bring on the jugglers and the clowns；〃 Pitt answered in good humor。
The safety line became taut and the long； slow haul began。 The rush of the surge through the shaft was matched by the gurgling of their exhaust bubbles from the air regulators。 With nothing to do now but grip the line； Pitt relaxed and went limp； allowing his body to be drawn against the flow of the underground current that gushed through the narrow slot like air through a venturi tube。 The lighter silt…clouded water in the pool at the end of the passage seemed miles away。 Time had no meaning； and he felt as if he'd been immersed for an age。 Only Giordino's steady voice helped Pitt keep his grip on reality。
〃Cry out if we haul too fast；〃 ordered Giordino。
〃Looking good；〃 Pitt replied； hearing his air tanks grinding against the ceiling of the shaft。
What is your estimate of the current's rate of speed？〃
〃Close to eight knots。〃
Small wonder your bodies are causing severe resistance。 I've got ten kids up here； pulling their hearts out。〃
〃Six more meters and we're out of here；〃 Pitt informed him。
And then a minute； probably a minute and a half； struggling to hold on to the safety line as they were buffeted by the diminishing force of the torrent； and they broke free of the shaft into the cloud of silt swirling around the floor of the sacrificial pool。 Another minute and they were pulled upward and clear from the drag of the current and into transparent； unclouded water。 Pitt looked up； saw the light filtering through the green slime； and felt a wondrous sense of relief。
Giordino knew they were free of the suction when the tension on the safety line suddenly diminished。 He ordered a halt to the ascent operation as he rechecked his depression data on a laptop puter。 One stop of eight minutes would take Pitt out of any danger of depression sickness； but the archaeology project divers would need stops of far longer duration。 They had been down over two hours at depths ranging from 17 to 37 meters （67 to 122 feet）。 They would require at least two stops lasting over an hour。 How much air was left in Pitt's tanks to sustain them？ That was the life…or…death dilemma。 Enough for ten minutes？ Fifteen？ Twenty？
At sea level； or one atmosphere； the normal human body contains about one liter of dissolved nitrogen。 Breathing larger quantities of air under the pressure of water depth increases the absorption of nitrogen to two liters at two atmospheres （10 meters； or 30 feet of water depth）； three liters at three atmospheres （30 meters； or 90 feet）； and so on。 During diving the excess nitrogen is rapidly dissolved in the blood； carried throughout the body； and stored in the tissues。 When a diver begins to ascend； the situation is reversed； only this time far more slowly。 As the water pressure decreases； the overabundance of nitrogen travels to the lungs and is eliminated by respiration。 If the diver rises too quickly； normal breathing can't cope and bubbles of nitrogen form in the blood； body tissue； and joints； causing depression sickness； better known as the bends； a condition that has crippled or killed thousands of divers over the past century。
Finally； Giordino set aside the puter and called Pitt。 〃Dirk？〃
〃I hear you。〃
〃Bad news。 There isn't enough air left in your tanks for the lady and her friend to make the necessary depression stops。〃
〃Tell me something I don't know；〃 Pitt came back。 〃What about backup tanks in the chopper？〃
〃No such luck；〃 moaned Giordino。 〃In our rush to leave the ship the crew threw on an air pressor but forgot to load extra air tanks。〃
Pitt stared through his face mask at Rodgers； still clutching his camera and shooting pictures。 The photographer gave him a thumbs up sign as though he'd just cleared the pool table at the neighborhood saloon。 Pitt's gaze moved to Shannon。 Her hazel eyes stared back at him through her face mask； wide and content as if she thought the nightmare was over and her hero was going to sweep her off to his castle。 She had not realized the worst was far from over。 For the first time he noticed that she had blond hair； and Pitt found himself wondering what she looked like in only her swim suit without the diving equipment。
The daydream was over almost as soon as it was begun。 His mind came back on an even keel and he spoke into his face mask receiver。 〃Al； you said the pressor is on board the chopper。〃
〃I did。〃
〃Send down the tool kit。 You'll find it in the storage locker of the chopper。〃
〃Make sense；〃 Giordino urged。
〃The manifold valves on my air tanks；〃 Pitt explained hastily。 〃They're the new prototypes NUMA is testing。 I can shut off one independently of the other and then remove it from the manifold without expelling air from the opposite tank。〃
〃I read you； pal；〃 said an enlightened Giordino。 〃You disconnect one of your twin tanks and breathe off the other。 I pull up the empty and refill it with the pressor。 Then we repeat the process until we satisfy the depression schedule。〃
〃A glittering concept； don't you think？〃 asked Pitt with dark sarcasm。
〃Fundamental at best；〃 grunted Giordino； artfully concealing his elation。 〃Hang at six…point…five meters for seventeen minutes。 I'll send the tool kit down to you on the safety line。 I just hope your plan works。〃
〃Never a doubt。〃 Pitt's confidence seemed genuine。 〃When I step onto firm ground again； I'll expect a Dixieland band playing ‘Waiting for the Robert E。 Lee'。〃
〃Spare me；〃 Giordino groaned。
As he ran toward the helicopter； he was confronted by Miller。
〃Why did you stop？〃 the anthropologist demanded。 〃Good God； man； what are you waiting for？ Pull them up！〃
Giordino fixed the anthropologist with an icy stare。 〃Pull them to the surface now and they die。〃
Miller looked blank。 〃Die？〃
〃The bends； Doc； ever hear of it？〃
A look of understanding crossed Miller's face； and he slowly nodded。 〃I'm sorry。 Please forgive an excitable old bone monger。 I won't trouble you again。〃
Giordino smiled sympathetically。 He continued to the helicopter and climbed inside； never suspecting that Miller's words were as prophetic as a lead dime。
The tool kit； consisting of several metric wrenches； a pair of pliers； two screwdrivers； and a geologist's hammer with a small pick on one end； was tied loosely to the safety line by a bowline knot and lowered by a small cord。 Once the tools were in Pitt's hands he gripped the air tank pack between his knees。 Next he adroitly shut off one valve and unthreaded it from the manifold with a wrench。 When one air tank came free； he attached it to the cord。
〃Cargo up；〃 Pitt announced。
In less than four minutes； the tank was raised by willing hands on the secondary cord； connected to the throbbing gas…engine pressor and taking on purified air。 Giordino was cursing； sweet talking； and begging the pressor to pump 3500 pounds of air per square inch into the 100…cubic…foot steel tank in record time。 The needle on the pressure gauge was just shy of 1800 pounds when Pitt warned him that Shannon's pony bottle was dry and his lone tank had only 400 pounds left。 With three of them sucking on one tank； that did not leave a fortable safety margin。 Giordino cut off the pressor when the pressure reached 2500 and wasted no time in sending the tank back down into the sinkhole。 The process was repeated three more times after Pitt and the other divers moved to their next depression stop at three meters； which meant they had to endure several minutes in the slime。 The whole procedure went off without a hitch。
Giordino allowed an ample safety margin。 He let nearly forty minutes pass before he pronounced it safe for Shannon and Rodgers to surface and be lifted to the brink of the sacrificial pool。 It was a measure of his plete confidence in his friend that Pitt didn't even bother to question the accuracy of Giordino's calculations。 Ladies went first as Pitt encircled Shannon's waist with the strap and buckle that was attached to the safety and munications line。 He waved to the faces peering over the edge and Shannon was on her way to dry land。
Rodgers was next。 His utter exhaustion after his narrow brush with death was forgotten at the sheer exhilaration of being lifted out of the godforsaken pool of death and slime； never； he swore； to return。 A gnawing hunger and a great thirst
