CHAPTER XXIII
AN UNDERSEA COLLISION
Under the warm, tropical sun the submarine floated idly on the surfaceof the calm sea. She had risen from the depths, her hatches had beenopened, and now the crew, the owner, and his guests were breathing freeair. The men were taking advantage of the period above water to washout some of their garments, hanging them on improvised lines stretchedalong the deck. For Tom Swift had said he would remain above thesurface all day.
Some slight repairs were necessary to the electric motors, and theycould be made only when the craft was on the open sea. This, too, wouldafford a chance to recharge the batteries and repair one of them.
For the time being the search under the sea for the treasure shipPandora had been abandoned. But it was not given up entirely. As Tomhad announced to Ned, a new theory would be worked out. So far,cruising about in the place where the fillibuster ship was supposed tohave gone down had resulted in nothing.
Mr. Damon, who had been below, shaving, came up on deck to see Tom andNed tossing into the water large pieces of cork taken from spare lifepreservers. Tom tossed his in from one side of the deck, and Ned fromthe other. Then, as the eccentric man listened, he heard Tom say:
"I think mine is going to beat yours, Ned!"
"Then you've got another guess coming," declared the young financialman. "Mine's going twice as fast as yours is now, though yours didstart off better."
"Bless my beefsteak!" exclaimed Mr. Damon, "what's this, Tom Swift? Ithought we came on a treasure-hunting expedition, and here I find youand Ned playing some childish game! I hope you aren't laying any wagerson it!" Mr. Damon did not approve of gambling in any form.
"No, we aren't doing that," laughed Tom, as he dropped another bit ofcork into the ocean.
"We are trying to arrive at some valuable scientific facts, Mr. Damon."
"Scientific facts--that childish play?"
"It isn't play," said Tom, turning to remark to Ned: "I think we'vesettled it. The current has a decided twist to the north."
"Yes," agreed his chum. "You were right, Tom."
"If you don't mind explaining," began Mr. Damon, "I should like toknow--"
"We're trying to determine the drift of the ocean currents in thislocality," Tom said.
"So we'll know better where to look for the Pandora," added Ned.
"Oh, so you haven't given up the hunt, then?" asked the eccentric man.
"By no means!" exclaimed Tom. "It's this way, Mr. Damon. We went downat as nearly the exact spot where the treasure-ship was sunk as wecould determine by means of calculations. She wasn't there, nor couldwe find her by going around in circles. Then it occurred to me, and tosome of the others also, including Ned, that the ocean currents mighthave shifted the position of the craft after she had sunk. There arepowerful currents in the ocean, as you know, the Gulf Stream being oneand the Japan Current another. Now there may be smaller ones in thesewaters that would produce a local effect.
"So Ned and I have been dropping bits of cork of different shapes intothe water and watching which way they drifted. Our conclusion is thatthe currents here have a decided set toward the north."
"And what does that indicate?" asked Mr. Damon.
"That we should have begun our search some distance north of the pointwhere we actually did begin," answered Tom.
"How far north?" the eccentric man wanted to know.
"That's just what we have yet to ascertain," the young inventorreplied. "So far our conclusions have been arrived at merely fromsurface data. Now we've got to go below."
"And play with bits of cork there?" asked Mr. Damon.
"No, we'll have to use something heavier than cork," Tom said. "We'llprobably use weights, and see how far they move along the bottom in agiven time. But we have established one thing, and I begin to havehopes now that we may locate the Pandora."
The remainder of the day was spent in various ways aboard thesubmarine, which continued to float idly on the waves.
It was toward evening, when the red, setting sun gave promise of a fairday on the morrow that the submarine's deck lookout approached Tom,and, waiting until he had the attention of the young inventor, reported:
"There is a smudge of smoke dead astern, sir."
"Is there?" exclaimed Tom. "Let me have the glasses."
He took them from the lookout and made a long and careful study of theslight, black smudge which was low down on the horizon.
"A steamer," decided Tom, "and coming on fast. We'll go below!" headded. "Please make ready," he said to the officer in charge.
"What's up, Tom?" asked Ned, as his chum gathered up the papers onwhich he had been figuring on an improvised table set under an awningon deck.
"Some craft is coming, and I'd just as soon she wouldn't sight us," wasthe answer.
"You mean she might interfere with our search for the treasure-ship?"
"Not exactly. But she might want to start a search on her own account,and there's no use of giving our presence away, or letting them guessat what might be right conclusions as to the location of the Pandora."
"But, Tom, no one knows of the wreck! At least, no one is supposed tobut our party and--"
"Hardley. Exactly!" exclaimed Tom, as he saw his chum about to utterthe name.
"And you think he is coming?"
"I shouldn't be a bit surprised. Anyhow, it's just as easy for us tosubmerge and let them do their own guessing. I was going down soon,anyhow, and another hour won't make any difference. Here, take a look,if you like."
Ned peered through the glasses, but his eyes not being trained in seainterpretation, as were Tom's, he could make out nothing but a blacksmudge, now larger and darker.
"It might be a cloud for all I can tell," he said, as he handed thebinoculars back to Tom.
"Well, it's a steamer all right, and she's under forced draft, too, ifI'm any judge. We'll go below before she sights us."
"Perhaps she has already," suggested Ned, as the crew began clearingthe submarine's deck.
"No, we lie too low in the water for that. Well, now we can start ourunderwater observations of current trends."
It did not take long, once she started, for the M. N. 1 to go down.Just as the sun sank below the horizon, and while the smudge of smokewas becoming more distinct, the waves closed over the steel deck of thesubmarine. Half an hour later she was nearly a quarter of a mile belowthe surface, resting on the bottom of the sea again.
On this trip Tom did not go to any such depths as he did on his formervoyage in the Advance. Not that the reconstructed submarine was notcapable of it, for she was even stronger than when first built. But thewreck they were seeking did not lie in so great a depth of water, andthere was no need of running useless risks.
"Well," remarked Ned, when they came to a stop, "I don't believe anyone will find us here."
"Not an ordinary diver, at any rate," Tom agreed. "And after supper I'mgoing to have another go at the currents."
The meal was served as usual, and a very good one it was, consideringthe fact that not as many supplies could be carried in the ratherlimited space of a submarine as may be transported in an ocean liner.Then, as it was still early, Tom and Ned, with the help of some of theofficers, got ready for a new series of experiments.
The big searchlight was set aglow, and, going out on the ocean bed indiving suits, Tom and his friends dropped on the sand various weightedobjects.
These were made in the shape of the hull of a steamer, and inproportion. Once they were on the sand, an iron rod was thrust into theocean bed near each object.
"Now," remarked Tom, as they all went into the submarine again, "we'lllet them drift until morning. Then we'll make new calculations. I thinkwe'll arrive at some results, too."
"Just what are you aiming to do?" asked Mr. Damon.
"See how far each one of those weighted objects drifts," Tom replied."We have planted them in different spots on the ocean bed. Some willdrift farther than others. Some are large and some
are small. Bystriking an average we may be able to tell about how far from thesupposed location of the Pandora we ought to look for her."
The night passed without incident and as calmly and peacefully asthough they were all in some deep cave beneath a great mountain. In themorning after breakfast Tom and his friends went outside the submarineagain and noted the weighted objects. Some had drifted farther thanothers. Measurements were carefully taken, and then began a series ofintricate calculations.
The distance each object had drifted from the iron bar marker wasconsidered in reference to its size and shape. Also the elapsed timewas computed. The results were then compared, an average struck, andthen the size and weight of the Pandora, as nearly as they could beascertained, were figured. The resultant figures were compared, and Tomannounced:
"If we are anywhere near right in our conclusions we ought to begin tosearch for the treasure-ship about four miles from here, in a generalnortherly direction."
"Do you think she has drifted that far?" asked Ned.
"Fully that," Tom answered. "That is only our starting point--thecenter of a new series of circles."
A moment later Tom gave the order to rise to the surface.
"Going up?" exclaimed Ned.
"Yes, I want to make some observations to determine our exact nauticalposition."
"But suppose that other steam--"
"We'll have to take a chance. We can submerge quickly if we have to,and I don't believe she's able to do that."
An observation was taken through the conning tower, however, before theM. N. 1 went all the way up, and there was not a sail nor a smudge ofsmoke on the horizon.
"So far so good," murmured Tom. "Now we'll 'shoot the sun,' and afterwe submerge we'll begin our search in earnest. I think we are on theright track now."
The observation was made at noon, and then, as nearly as possible, thesubmarine was moved to a position approximately four miles north of theplace where the Pandora was supposed to have foundered.
"Down we go!" exclaimed Tom, and down they went.
The depth gauge showed more than a thousand feet below the surface whenthe M. N. 1 came to rest. This was deeper than Tom had thought to findthe wreck, but his craft was able to withstand the pressure. A briefwait, to make sure that everything was in readiness, was followed bythe beginning of the new search. In gradually widening circles thecraft moved about under water.
If the voyagers had expected to locate at once the treasure-ship, theywould have been disappointed. For the first day gave no signs. But Tomhad not promised immediate results, and no one gave up hope.
It was shortly after noon on the second day of the search at the newlocation that, as they were proceeding at rather greater speed thanusual, something happened.
Ned had just suggested that he and Tom might go out and try thecurrent-setting experiments again, when suddenly they were both thrownoff their feet by a terrific jar and concussion. The M. N. 1 seemed toreel back, as if from a great blow.
"Bless my safety razor!" cried Mr. Damon, "what's the matter, Tom?"
"I think we've had a collision!" was the answer. "I must see how badlywe are damaged!"