"And the carboys burst from the heat and ruined the sails," broke in the doctor. "But another question is, what became of that acid?"
"If it"s not in the "tween-deck yet, it must be in the hold--leaked through the hatches."
"I hope it hasn"t reached the iron in the hull, Boston, my boy. It takes a long time for cold acids to act on iron after the first oxidation, but in fifty years mixed nitric and sulphuric will do lots of work."
"No fear, Doc; it had done its work when you were in your cradle.
What"ll we do for canvas? We must get this craft before the wind.
How"ll the carpet do?" Boston lifted the edge, and tried the fabric in his fingers. "It"ll go," he said; "we"ll double it. I"ll hunt for a palm-and-needle and some twine." These articles he found in the mate"s room. "The twine"s no better than yarn," said he, "but we"ll use four parts."
Together they doubled the carpet diagonally, and with long st.i.tches joined the edges. Then Boston sewed into each corner a thimble--an iron ring--and they had a triangular sail of about twelve feet hoist.
"It hasn"t been exposed to the action of the air like the ropes in the locker forward," said Boston, as he arose and took off the palm; "and perhaps it"ll last till she pays off. Then we can steer. You get the big pulley-blocks from the locker, Doc, and I"ll get the rope from the boat. It"s lucky I thought to bring it; I expected to lift things out of the hold with it."
At the risk of his life Boston obtained the coil from the boat, while the doctor brought the blocks. Then, together, they rove off a tackle.
With the handles of their pistols they knocked bunk-boards to pieces and saved the nails; then Boston climbed the foremast, as a painter climbs a steeple--by nailing successive billets of wood above his head for steps. Next he hauled up and secured the tackle to the forward side of the mast, with which they pulled up the upper corner of their sail, after lashing the lower corners to the windla.s.s and fiferail.
It stood the pressure, and the hulk paid slowly off and gathered headway. Boston took the wheel and steadied her at northwest by west--dead before the wind--while the doctor, at his request, brought the open can of soup and lubricated the wheel-screw with the only subst.i.tute for oil at their command; for the screw worked hard with the rust of fifty years.
Their improvised sail, pressed steadily on but one side, had held together, but now, with the first flap as the gale caught it from another direction, appeared a rent; with the next flap the rag went to pieces.
"Let her go!" sang out Boston gleefully; "we can steer now. Come here, Doc, and learn to steer."
The doctor came; and when he left that wheel, three days later, he had learned. For the wind had blown a continuous gale the whole of this time, which, with the ugly sea raised as the ship left the lee of the land, necessitated the presence of both men at the helm. Only occasionally was there a lull during which one of them could rush below and return with a can of soup. During one of these lulls Boston had examined the boat, towing half out of water, and concluded that a short painter was best with a water-logged boat, had reinforced it with a few turns of his rope from forward. In the three days they had sighted no craft except such as their own--helpless--hove-to or scudding.
Boston had judged rightly in regard to the wind. It had hauled slowly to the southward, allowing him to make the course he wished--through the Bahama and up the Florida Channel with the wind over the stern.
During the day he could guide himself by landmarks, but at night, with a darkened binnacle, he could only steer blindly on with the wind at his back. The storm centre, at first to the south of Cuba, had made a wide circle, concentric with the curving course of the ship, and when the latter had reached the upper end of the Florida channel, had spurted ahead and whirled out to sea across her bows. It was then that the undiminished gale, blowing nearly west, had caused Boston, in despair, to throw the wheel down and bring the ship into the trough of the sea--to drift. Then the two wet, exhausted, hollow-eyed men slept the sleep that none but sailors and soldiers know; and when they awakened, twelve hours later, stiff and sore, it was to look out on a calm, starlit evening, with an eastern moon silvering the surface of the long, northbound rollers, and showing in sharp relief a dark horizon, on which there was no sign of land or sail.
They satisfied their hunger; then Boston, with a rusty iron pot from the galley, to which he fastened the end of his rope, dipped up some of the water from over the side. It was warm to the touch, and, aware that they were in the Gulf Stream, they crawled under the musty bedding in the cabin berths and slept through the night. In the morning there was no promise of the easterly wind that Boston hoped would come to blow them to port, and they secured their boat--reeving off davit-tackles, and with the plug out, pulling it up, one end at a time, while the water drained out through the hole in the bottom.
"Now, Boston," said the doctor, "here we are, as you say, on the outer edge of the Gulf Stream, drifting out into the broad Atlantic at the rate of four miles an hour. We"ve got to make the best of it until something comes along; so you hunt through that store-room and see what else there is to eat, and I"ll examine the cargo. I want to know where that acid went."
They opened all the hatches, and while Boston descended to the lazarette, the doctor, with his trousers rolled up, climbed down the notched steps in a stanchion. In a short time he came up with a yellow substance in his hand, which he washed thoroughly with fresh water in Boston"s improvised draw-bucket, and placed in the sun to dry. Then he returned to the "tween-deck. After a while, Boston, rummaging the lazarette, heard him calling through the bulkhead, and joined him.
"Look here, Boston," said the doctor; "I"ve cleared away the muck over this hatch. It"s "corked," as you sailormen call it. Help me get it up."
They dug the compacted oak.u.m from the seams with their knives, and by iron rings in each corner, now eaten with rust to almost the thinness of wire, they lifted the hatch. Below was a filthy-looking layer of whitish substance, protruding from which were charred, half-burned staves. First they repeated the experiment with the smouldering rag, and finding that it burned, as before, they descended. The whitish substance was hard enough to bear their weight, and they looked around.
Overhead, hung to the under side of the deck and extending the length of the hold, were wooden tanks, charred, and in some places burned through.
"She must have been built for a pa.s.senger or troop ship," said Boston.
"Those tanks would water a regiment."
"Boston," answered the doctor, irrelevantly, "will you climb up and bring down an oar from the boat? Carry it down--don"t throw it, my boy." Boston obliged him, and the doctor, picking his way forward, then aft, struck each tank with the oar. "Empty--all of them," he said.
He dug out with his knife a piece of the whitish substance under foot, and examined it closely in the light from the hatch.
"Boston," he said, impressively, "this ship was loaded with lime, tallow, and acids--acids above, lime and tallow down here. This stuff is neither; it is lime-soap. And, moreover, it had not been touched by acids." The doctor"s ruddy face was ashen.
"Well?" asked Boston.
"Lime soap is formed by the cauticizing action of lime on tallow in the presence of water and heat. It is easy to understand this fire. One of those tanks leaked and dribbled down on the cargo, attacking the lime--which was stowed underneath, as all these staves we see on top are from tallow-kids. The heat generated by the slaking lime set fire to the barrels in contact, which in turn set fire to others, and they burned until the air was exhausted, and then went out. See, they are but partly consumed. There was intense heat in this hold, and expansion of the water in all the tanks. Are tanks at sea filled to the top?"
"Chock full, and a cap screwed down on the upper end of the pipes."
"As I thought. The expanding water burst every tank in the hold, and the cargo was deluged with water, which attacked every lime barrel in the bottom layer, at least. Result--the bursting of those barrels from the ebullition of slaking lime, the melting of the tallow--which could not burn long in the closed-up-s.p.a.ce--and the mixing of it in the interstices of the lime barrels with water and lime--a boiling hot mess. What happens under such conditions?"
"Give it up," said Boston, laconically.
"Lime soap is formed, which rises, and the water beneath is in time all taken up by the lime."
"But what of it?" interrupted the other.
"Wait. I see that this hold and the "tween-deck are lined with wood.
Is that customary in iron ships?"
"Not now. It used to be a notion that an iron skin damaged the cargo; so the first iron ships were ceiled with wood."
"Are there any drains in the "tween-deck to let water out, in case it gets into that deck from above--a sea, for instance?"
"Yes, always; three or four scupper-holes each side amidships. They lead the water into the bilges, where the pumps can reach it."
"I found up there," continued the doctor, "a large piece of wood, badly charred by acid for half its length, charred to a lesser degree for the rest. It was oval in cross section, and the largest end was charred most."
"Scupper plug. I suppose they plugged the "tween-deck scuppers to keep any water they might ship out of the bilges and away from the lime."
"Yes, and those plugs remained in place for days, if not weeks or months, after the carboys burst, as indicated by the greater charring of the larger end of the plug. I burrowed under the debris, and found the hole which that plug fitted. It was worked loose, or knocked out of the hole by some internal movement of the broken carboys, perhaps.
At any rate, it came out, after remaining in place long enough for the acids to become thoroughly mixed and for the hull to cool down. She was in the ice, remember. Boston, the mixed acid went down that hole, or others like it. Where is it now?"
"I suppose," said Boston, thoughtfully, "that it soaked up into the hold, through the skin."
"Exactly. The skin is calked with oak.u.m, is it not?" Boston nodded.
"That oak.u.m would contract with the charring action, as did the oak.u.m in the hatch, and every drop of that acid--ten thousand gallons, as I have figured--has filtered up into the hold, with the exception of what remained between the frames under the skin. Have you ever studied organic chemistry?"
"Slightly."
"Then you can follow me. When tallow is saponified there is formed, from the palmitin, stearin, and olein contained, with the cauticizing agent--in this case, lime--a soap. But there are two ends to every equation, and at the bottom of this immense soap vat, held in solution by the water, which would afterwards be taken up by the surplus lime, was the other end of this equation; and as the yield from tallow of this other product is about thirty per cent., and as we start with eight thousand fifty-pound kids--four hundred thousand pounds--all of which has disappeared, we know that, sticking to the skin and sides of the barrels down here, is--or was once--one hundred and twenty thousand pounds, or sixty tons, of the other end of the equation--glycerine!"
"Do you mean, Doc," asked Boston, with a startled look, "that--"
"I mean," said the doctor, emphatically, "that the first thing the acids--mixed in the "tween-deck to just about the right proportions, mind you--would attack, on oozing through the skin, would be this glycerine; and the certain product of this union under intense cold--this hull was frozen in the ice, remember--would be nitro-glycerine; and, as the yield of the explosive is two hundred and twenty per cent. of the glycerine, we can be morally sure that in the bottom of this hold, each minute globule of it held firmly in a hard matrix of sulphate or nitrate of calcium--which would be formed next when the acids met the hydrates and carbonates of lime--is over one hundred and thirty tons of nitro-glycerine, all the more explosive from not being washed of free acids. Come up on deck. I"ll show you something else."
Limp and nerveless, Boston followed the doctor. This question was beyond his seamanship.
The doctor brought the yellow substance--now well dried. "I found plenty of this in the "tween-deck," he said; "and I should judge they used it to pack between the carboy boxes. It was once cotton-batting.
It is now, since I have washed it, a very good sample of gun-cotton.
Get me a hammer--crowbar--something hard."
Boston brought a marline-spike from the locker, and the doctor, tearing off a small piece of the substance and placing it on the iron barrel of a gipsy-winch, gave it a hard blow with the marline spike, which was nearly torn from his hand by the explosion that followed.