Chapter Thirteen
Off for the Treasure
Suddenly Tom, after a moment's pause, seized a wrench and beganloosening some nuts.
"What are you doing?" asked his father faintly, for he was beingweakened by the vitiated atmosphere.
"I'm going to take this valve apart," replied his son. "We haven'tlooked there for the trouble. Maybe it's out of order."
He attacked the valve with energy, but his hands soon lagged. The lackof oxygen was telling on him. He could no longer work quickly.
"I'll help," murmured Mr. Sharp thickly. He took a wrench, but nosooner had he loosened one nut than he toppled over. "I'm all in," hemurmured feebly.
"Is he dead?" cried Mr. Damon, himself gasping.
"No, only fainted. But he soon will be dead, and so will all of us, ifwe don't get fresh air," remarked Captain Weston. "Lie down on thefloor, every one. There is a little fairly good air there. It's heavierthan the air we've breathed, and we can exist on it for a littlelonger. Poor Sharp was so used to breathing the rarified air of highaltitudes that he can't stand this heavy atmosphere."
Mr. Damon was gasping worse than ever, and so was Mr. Swift. Theballoonist lay an inert heap on the floor, with Captain Weston tryingto force a few drops of stimulant down his throat.
With a fierce determination in his heart, but with fingers that almostrefused to do his bidding, Tom once more sought to open the big valve.He felt sure the trouble was located there, as they had tried to locateit in every other place without avail.
"I'll help," said Mr. Jackson in a whisper. He, too, was hardly able tomove.
More and more devoid of oxygen grew the air. It gave Tom a sense as ifhis head was filled, and ready to burst with every breath he drew.Still he struggled to loosen the nuts. There were but four more now,and he took off three while Mr. Jackson removed one. The young inventorlifted off the valve cover, though it felt like a ton weight to him. Hegave a glance inside.
"Here's the trouble!" he murmured. "The valve's clogged. No wonder itwouldn't work. The pumps couldn't force the water out."
It was the work of only a minute to adjust the valve. Then Tom and theengineer managed to get the cover back on.
How they inserted the bolts and screwed the nuts in place they nevercould remember clearly afterward, but they managed it somehow, withshaking, trembling hands and eyes that grew more and more dim.
"Now start the pumps!" cried Tom faintly. "The tanks will be emptied,and we can get to the surface."
Mr. Sharp was still unconscious, nor was Mr. Swift able to help. He laywith his eyes closed. Garret Jackson, however, managed to crawl to theengine-room, and soon the clank of machinery told Tom that the pumpswere in motion. The lad staggered to the pilot house and threw thelevers over. An instant later there was the hissing of water as itrushed from the ballast tanks. The submarine shivered, as thoughdisliking to leave the bottom of the sea, and then slowly rose. As thepumps worked more rapidly, and the sea was sent from the tank in greatvolumes, the boat fairly shot to the surface. Tom was ready to open theconning tower and let in fresh air as soon as the top was above thesurface.
With a bound the Advance reached the top. Tom frantically worked theworm gear that opened the tower. In rushed the fresh, life-giving air,and the treasure-hunters filled their lungs with it.
And it was only just in time, for Mr. Sharp was almost gone. He quicklyrevived, as did the others, when they could breathe as much as theywished of the glorious oxygen.
"That was a close call," commented Mr. Swift. "We'll not go below againuntil I have provided for all emergencies. I should have seen to theair tanks and the expanding one before going below. We'll sail home onthe surface now."
The submarine was put about and headed for her dock. On the way shepassed a small steamer, and the passengers looked down in wonder at thestrange craft.
When the Advance reached the secluded creek where she had beenlaunched, her passengers had fully recovered from their terribleexperience, though the nerves of Mr. Swift and Mr. Damon were not atease for some days thereafter.
"I should never have made a submerged test without making sure that wehad a reserve supply of air," remarked the aged inventor. "I will notbe caught that way again. But I can't understand how the pump valve gotout of order."
"Maybe some one tampered with it," suggested Mr. Damon. "Could AndyFoger, any of the Happy Harry gang, or the rival gold-seekers have doneit?"
"I hardly think so," answered Tom. "The place has been too carefullyguarded since Berg and Andy once sneaked in. I think it was just anaccident, but I have thought of a plan whereby such accidents can beavoided in the future. It needs a simple device."
"Better patent it," suggested Mr. Sharp with a smile.
"Maybe I will," replied the young inventor. "But not now. We haven'ttime, if we intend to get fitted out for our trip."
"No; I should say the sooner we started the better," remarked CaptainWeston. "That is, if you don't mind me speaking about it," he addedgently, and the others smiled, for his diffident comments were only amatter of habit.
The first act of the adventurers, after tying the submarine at thedock, was to proceed with the loading of the food and supplies. Tom andMr. Damon looked to this, while Mr. Swift and Mr. Sharp made somenecessary changes to the machinery. The next day the young inventorattached his device to the pump valve, and the loading of the craft wascontinued.
All was in readiness for the gold-seeking expedition a week later.Captain Weston had carefully charted the route they were to follow, andit was decided to move along on the surface for the first day, so as toget well out to sea before submerging the craft. Then it would sinkbelow the surface, and run along under the water until the wreck wasreached, rising at times, as needed, to renew the air supply.
With sufficient stores and provisions aboard to last several months, ifnecessary, though they did not expect to be gone more than sixty daysat most, the adventurers arose early one morning and went down to thedock. Mr. Jackson was not to accompany them. He did not care about asubmarine trip, he said, and Mr. Swift desired him to remain at theseaside cottage and guard the shops, which contained much valuablemachinery. The airship was also left there.
"Well, are we all ready?" asked Mr. Swift of the little party ofgold-seekers, as they were about to enter the conning tower hatchway ofthe submarine.
"All ready, dad," responded his son.
"Then let's get aboard," proposed Captain Weston. "But first let metake an observation."
He swept the horizon with his telescope, and Tom noticed that thesailor kept it fixed on one particular spot for some time.
"Did you see anything?" asked the lad.
"Well, there is a boat lying off there," was the answer. "And some oneis observing us through a glass. But I don't believe it matters.Probably they're only trying to see what sort of an odd fish we are."
"All aboard, then," ordered Mr. Swift, and they went into thesubmarine. Tom and his father, with Captain Weston, remained in theconning tower. The signal was given, the electricity flowed into theforward and aft plates, and the Advance shot ahead on the surface.
The sailor raised his telescope once more and peered through a windowin the tower. He uttered an exclamation.
"What's the matter?" asked Tom.
"That other ship--a small steamer--is weighing anchor and seems to beheading this way," was the reply.
"Maybe it's some one hired by Berg to follow us and trace ourmovements," suggested Tom.
"If it is we'll fool them," added his father. "Just keep an eye onthem, captain, and I think we can show them a trick or two in a fewminutes."
Faster shot the Advance through the water. She had started on her wayto get the gold from the sunken wreck, but already enemies were on thetrail of the adventurers, for the ship the sailor had noticed wassteaming after them.