CHAPTER XX.
Launch the submarine boat. Experiment with it in Stillwater Cove.
Having completely finished and arranged my boat, my next task was tolaunch it and arrange for a series of experiments to ascertain itspractical value. So one fine morning I went forth, with a beatingheart, from the Hermitage, and waited patiently till nearly high water,and having greased my launching ways, and confined the cradle with along and strong rope of rawhide, so that its momentum, when launched,should not carry it across Stillwater Cove without being checked beforeit reached the other side, I, with anxiety and almost fear, withdrewthe iron bolts in front of it on the ways, and, going to the upperend, applied a crowbar to the still stationary mass, and after a fewmotions of the bar it began to move, and with one grand rush, not veryfast, and yet majestic and striking, the cradle, with its preciousfreight, dashed into the water, and, being brought up by the long ropeof rawhide fast to it, in a moment or two rested quietly upon its bosom.
I took the canoe "Fairy" and paddled all about it and saw that it satwell balanced, and secure, and that it floated beautifully. I thenmade fast to it with a short piece of rawhide rope, and commencedtowing it to the mouth of Stillwater Cove, where the water was deep butsmooth, to still further carry on my experiments. It was a good hardday's work to tow the heavy cradle to the place that I had fixed upon,which was at the mouth of Stillwater Cove, just within the breakwater,and about one mile beyond the landing-place and two or three miles fromthe Hermitage. This place was admirably fitted for my purposes, theshore being of a smooth sand and the water gradually deepening towardsthe centre of the cove. Nothing but clear, pure sea-sand on the bottom,and no rock to injure the boat or interfere with any experiment I mightchoose to make. Having arrived, I was glad to anchor the whole concernsafely, and to make my way home in the canoe.
The next day, fitted out with all I thought I should need, includingmy two goats for the treadmill and provisions for a day or two, Imade my way back again in the canoe to the floating cradle. I foundeverything all right, as I had left it, and proceeded to prove thepractical efficiency of my invention. In the first place I took thegoats on shore and tethered them, so that they could feed, but notescape. I then went to work and anchored the cradle in about twelvefeet of water, it then being nearly low tide, or slack water. Afterhaving secured both it and the boat also, I went to work sawing off theslats of the cradle upon which the latter rested, and in less thantwo hours the last one was off, and I had the satisfaction of seeingmy boat floating in the water, drawing only a few inches, certainlynot over six, with the manhole open, sustained wholly by the confinedair in the tanks, which held up the superstructure bravely. After theslats were cut away I drove out the pins from the mortised framework ofthe cradle and left my iron boat floating calmly on the bosom of thesmooth waters of Stillwater Cove. Floating the timbers to one side thathad formed the cradle, I allowed them to drift up stream with the nowincoming tide, the boat being securely anchored by two anchors, one inadvance and one at the stern, which were made fast to two ringbolts onthe roof, placed at each extremity.
And now for my final test. I had made up my mind, if the thing wasnot a success, that I did not intend to be personally implicated inany disaster. Two things only could happen; one, that the boat mightcapsize, and if so I was prepared to go on board with little clothing,so that if it vomited me up I could easily reach the surface and thenswim ashore, which was distant only a few rods; the other, that Ishould be unable to improve my air, once vitiated or used up. In thelatter event I had only to dive out from under the boat and again makemy way to the shore, losing, however, the lives of my poor goats.
I commenced my work by going on board of the boat by means of a shortladder, which reached from the manhole to the deck beneath. In thefirst place I shipped or hung the wooden shelves on each of the tanks,and loaded them with several iron weights, and also large smooth stonesand the two anchors that belonged to the boat. This made it very firm,and sunk the tanks at least two inches more. I then went on shore andbrought off my goats in the canoe and passed them on board through themanhole, which I had made large for this very purpose. I then went towork in the interior and fixed my compass, steering-gear, treadmill,and propeller, taking great care to see that my spray-wheel was all inorder, and at hand ready to be hung.
I also conveyed on board some candles, flint and steel, matches, andprovisions, and as the last thing took in the stern anchor, so that theboat lay with the tide, tailing up stream. The other hawser I conveyedalso--by means of the canoe and with a boathook--under the forwardtank, so that I held the end within the interior, and could cast itoff at anytime. It was by the sun about eleven o'clock when I gave oneglance around me, and, standing on the last round of the ladder, I drewthe manhole cover over my head and commenced screwing it down on theinside, which having done I lighted several candles, although I had afair light reflected from the water and the bottom of the cove, formedof white sea-sand, directly beneath me, and distant, I should judge bythe state of the tide, some twenty to twenty-five feet. My goats hadbecome so accustomed to the boat that they showed little surprise atthe rather dim light, and stood ready to perform their part whenever Ishould put them to their customary task.
My heart beat rapidly, not with fear, but with excitement andexpectation. Here I was, already shut out from the outer air, and ina little world of my own. I hesitated to complete my experiment, andbefore going further I turned to my provisions and took a good longdrink of claret wine to strengthen my courage and steady my nerves.If I was in a scrape I could get out of it, but my poor goats! they,I was afraid, would have to pay for any error in judgment on my part.Having regained perfect composure, I made up my mind to make thefirst test of the practical value of my boat, and that was to see ifI could descend to the bottom of the ocean, that lay beneath me. Bymoving around I felt convinced that my calculations about the centre ofgravity had been correct, and I felt that the boat would not capsize.It was remarkably stiff and steady, and would, I felt confident, remainso when submerged. This bugbear was already off my mind, and gaveme confidence to proceed. So, moving to the place on the starboardside where all my pipes and stopcocks were congregated, I commencedby opening the stopcock of the water-pipe, which, as I had foreseen,brought no perceptible change. Some little water rushed into the tanks,but only what was sufficient to compress the air to the extent of theweight of the superstructure of the boat. This experiment did not sinkit one particle; its buoyancy remained exactly the same, for the sameair remained in the tanks, although compressed, and was not able toescape on account of the position of the outlet of the pipe that hadopened communication between it and the water, pointing, as it did,directly to the centre of the earth. After waiting a little, and seeingthat this all worked well, I placed my hand upon the stopcock of a moreimportant pipe, namely the tank air-pipe, which led from the tanks tothe outer surface of the superstructure.
Now, or never! Upon turning this cock I should descend or my theorywould be incorrect. The moment my hand opened this valve the air wouldbe expelled by the pressure of the boat upon the water, conveyed tothe air in the tanks by the water-pipe, which was already open; and,as it was expelled, so the buoyancy of the boat would be decreased,and I should descend. The fatal moment had come, and with a firmhand I opened the tank air-pipe, and plainly heard the escaping air,the incoming water, and felt the boat descending, and saw the sandybottom apparently approaching me. I cut off the discharge of the tankair-pipe, and with a slight rebound the boat arose again a few inchestowards the surface, simply regaining its true position in equilibrio,that it had for a moment passed, by the momentum of its descent. Bylittle turns of this stopcock I discovered, as I expected, that Icould move the boat in a descending direction even an inch at a time.The movement was a perfect fascination, but each delivery of air wasbringing me nearer the bottom, and as yet I had tried no means ofrising again to the surface.
When I had gotten to within about six feet of the former I thought ittime to s
ee if I could again rise towards the surface. I was well awarethat, having used up this air, it was so much loss to me, but I was inhopes to be able to replace it; and even if I could not replace it tomake the boat rise to near the surface without it. I could do this inone way, by casting overboard the anchors and weights lying upon thewooden shelves; but this, if done to any great extent, might cause thecapsizing of the whole affair. No; I had a better way than this, and atit I went. In the first place I closed the water-pipe, and then, havingopened the screw-valve in the connected tanks, I screwed upon it thepump and commenced discharging the water from them--that had run into take the place of the discharged air--into the water of the ocean,which formed, in one sense, the interior flooring of my boat.
To make this pump work I of course opened, and left open, thepump-pipe, so that the air from the interior rushed in and filled thetank as fast as the pump discharged the water, and at each stroke ofthe pump, after the first few, the boat, as I had hoped, began to rise;the water, having been just so much ballast to carry it down, beingdischarged by the pump, was just so much thrown overboard in weight toallow it to rise. By persistent pumping I made my boat rise quite nearthe surface, but not to the buoyant position it at first maintained,for I had in my descent used up considerable of the air in the tanks,which I had as yet not replaced, or rather what I had used from themhad been replaced from the air of the interior when I pumped out thewater, which I could only do by allowing the connection between thetanks and the interior to be open, so as to make the pump work. Inshort I had lost just so much buoyancy as was equal to the escaped air;but still I had been able to make the boat descend and ascend.
These experiments took me over two hours, and I commenced to feel theneed of new air, and to notice that my candles began to burn a littledimly. I was thus warned that my air was being used up and charged withcarbonic gas, and that it was time for me to renew it. So I unscrewedthe pump and closed the valve, opened the water-pipe, and placed myhand upon the tank air-pipe and prepared to descend. One effect Ishould have noticed of my loss of air, and that was that the water inthe interior of the boat rose considerably, and a large portion ofthe tanks was now submerged. A few turns of the stopcock of the tankair-pipe carried me near to the bottom, where I desired to be, to trymy last and most important experiment.
Arriving to within a few feet of the bottom I rigged my spray-wheel,and connected it with the drum of the treadmill and set the goats atwork. And it was time, for my breathing had become oppressive, and theanimals themselves seemed dull and frightened. I had waited almost toolong. My candles also commenced to burn more dimly, and I prepared totake my plunge into the water and come up outside of the boat shouldmy experiment now fail. But wonder of wonders! my spray-wheel madebut a few revolutions, dashing large quantities of minute spray intothe interior by its rapid motion, before my lungs were relieved, thecandles renewed their brilliancy, and the goats recovered from thelassitude under which they had a moment before seemed to be laboring.
The problem was solved. I had made my own air. I could remain belowthe surface as long as I desired. Everything about me was rather dampand moist from the dashing of spray about the interior, and severalof the candles, that I had not protected, were put out; but two, inthe extremity of the boat, were preserved, and now that my problem wassolved I did not again light the former, the two remaining ones beingall-sufficient. And in fact I did not need them; my own lungs, I found,were sufficient as a guide to tell me in future when to renew the air.Still it was fascinating to see these two candles burning brilliantlythat had but a moment before been so dim. The reflected light from thepure sandy bottom just below me was amply sufficient for all purposes.
I imagined, by the slight shadow that the boat cast on the bottombeneath, from the brilliant sun that I knew was shining overhead, andfrom counting up in my mind all I had done since leaving the surface,that the air had lasted me, as nearly as I could judge, two hours;and that seemed to be the extreme limit to which I could go and notrenew it. I also knew by the quantity of tallow consumed in the candlesthat it must be nearly that amount of time. I also noticed that thespray-wheel had not only purified my air, but that whilst it was inoperation the boat had slightly ascended, proving that I had gained alighter gas for the nitrogen and carbonic acid precipitated.
One more thing remained to be tested, and I should feel that my laborswere complete. In the first place I made the boat ascend as far aspossible, by means of the pump and stopcocks, as before described, andthen I went to work and rigged my propeller and set the goats at work.I got the boat as near the surface as possible before communicatingmotion to it, so as not to run against any obstacle if possible. Butthen the body of water in which I was submerged was so pure, and freefrom anything of that nature, that there was little danger after all.With a feeling of confidence that I had not had in all the otherexperiments, I cast off the hawser affixed to the anchor that held theboat, and started the goats. Mechanics did not trouble me, and it waswith no surprise, but only gratification, that I saw by the bottomthat the boat was moving forward, and that it readily obeyed the helm.I turned it completely around by the tiller, and made an excursion offully half a mile, I should think, up Stillwater Cove, once in a whilegetting out of the channel, when by stopping the goats and reversingthe propeller I was able to back into the channel again, and finallyto turn around by a series of forward and backward motions till Iagain arrived at the place from which I had started, which I knew bythe anchor lying in mid-channel. By observation of the bottom I shouldsay that the boat was propelled at least three miles an hour, which wassufficient for all my purposes.
After arriving back to my first position I pointed the boat towardsthe sandy beach, and when the hanging shelves touched the bottom Icarefully removed them and their weights to the top of the tanks, inthe interior, and, with a short pole, pushed the boat still nearer theshore, till the tanks rested on the sand; and this I did with careand quickly, for I was a little afraid of a capsize when the hangingshelves were removed, which was only for a moment or two, however,before the boat was at rest on its own foundations, on the sand. I thenforced down under the water from the interior quite a large block ofwood under the tank that had the water pipe protruding, so that thelatter should not be hurt by being driven into the sand when the wholeboat was stranded at low water.
The tide being now at ebb, I knew that I had not long to wait beforethe whole boat would be high and dry upon the sand. But having gottenmy piece of timber under the tank to protect the water pipe, I openedthe atmospheric pipe and let the whole boat sink solidly to the bottom,in all its parts, as well as the forward part that was resting onthe sand. I then cautiously opened the manhole, ready to close itimmediately should it yet be below the surface; but, as I supposed, itwas out of the water at least six inches, and, throwing it open, I onceagain emerged into the open air of day.
I released the goats and carried them on shore, and as the tide recededall the water left my tanks through the water pipe, which I thenclosed, and there was my boat as buoyant again as when it was firstlaunched, with all the tanks full of air, and ready to be towed to ananchorage as soon as the next incoming tide should float it.
I lay down upon the sea-side and contemplated my work, and wonderedif it would not make me a rich man if I could transport it to somecivilized portion of the earth. Was it possible for me to make a boatof this kind on a large scale, with a team of goats, fifteen or twentyin number, and traverse the depths of the ocean till I arrived at someChristian land? One thing at least was in its favor: I need fear nostorms or any dangers of the ocean from waves or wind, and one othergreat obstacle would be overcome. I could leave the helm at any timeand go to sleep, feeling sure that my boat would not be driven about bywaves and winds, but repose peacefully in eqilibrio till I again awoke,and forced it forward upon its passage.
There was matter for great thought in all this. But on the other hand,should my air fail me, or my tanks leak, or steering apparatus getout of order, I should ei
ther be stifled to death, drowned, or leftbeneath the ocean to wear out a miserable existence till death relievedme. The risk was too great. Besides I had no means but a compass ofascertaining where I was going, no glass lens to give me any light;but perhaps I might possibly make the latter. It was all well enoughfor me to venture out from my island where at the worst I could escapeand swim ashore; and, if the truth must be spoken, I found myself toomuch in love with my island, and all its comforts, to hazard too muchto escape from it. I cannot say that I did not long and long to escape,and that I did not mourn for companionship; but I must also confessthat I had begun to love my island home also, in one sense, and I couldsee far enough ahead now into the future to acknowledge to myself that,should I escape, it would be only to return with companions to here endmy days.
These were different feelings than what I had when first cast on theisland, as will readily be perceived by perusal of this manuscript,if ever, by the mercy of God, it comes to anybody's hands to read.But what could I--an old sailor, but not an old man, who had bangedaround the world--ask for more than I could obtain on my island exceptcompanionship? Nothing.
Having secured the boat, and put the goats and spare traps into thecanoe, I at the close of the day paddled myself back to the Hermitage,determined on the morrow to make an excursion out of Stillwater Coveinto the ocean, and see what I could discover. To be doubly secure Imade up my mind to tow the canoe with a long rope of rawhide on thesurface of the water, astern of the submarine boat below it, so thatif I did meet with disaster or shipwreck I could get into the formerand make my way to the shore in safety,--in fact this arrangement wouldtake away all danger from the enterprise, as I felt confident that Icould always escape from the boat, and it would be well worth while tohave the canoe at hand to jump into, if I had to do so.