CHAPTER XV
THE FETE OF THE CASTING
During the eight months which were employed in the work ofexcavation the preparatory works of the casting had been carriedon simultaneously with extreme rapidity. A stranger arriving atStones Hill would have been surprised at the spectacle offeredto his view.
At 600 yards from the well, and circularly arranged around it asa central point, rose 1,200 reverberating ovens, each six feetin diameter, and separated from each other by an interval ofthree feet. The circumference occupied by these 1,200 ovenspresented a length of two miles. Being all constructed on thesame plan, each with its high quadrangular chimney, theyproduced a most singular effect.
It will be remembered that on their third meeting the committeehad decided to use cast iron for the Columbiad, and in particularthe white description. This metal, in fact, is the mosttenacious, the most ductile, and the most malleable, andconsequently suitable for all moulding operations; and whensmelted with pit coal, is of superior quality for allengineering works requiring great resisting power, such ascannon, steam boilers, hydraulic presses, and the like.
Cast iron, however, if subjected to only one single fusion,is rarely sufficiently homogeneous; and it requires a secondfusion completely to refine it by dispossessing it of its lastearthly deposits. So long before being forwarded to Tampa Town,the iron ore, molten in the great furnaces of Coldspring, andbrought into contact with coal and silicium heated to a hightemperature, was carburized and transformed into cast iron.After this first operation, the metal was sent on to Stones Hill.They had, however, to deal with 136,000,000 pounds of iron, aquantity far too costly to send by railway. The cost oftransport would have been double that of material. It appearedpreferable to freight vessels at New York, and to load them withthe iron in bars. This, however, required not less than sixty-eight vessels of 1,000 tons, a veritable fleet, which, quittingNew York on the 3rd of May, on the 10th of the same month ascendedthe Bay of Espiritu Santo, and discharged their cargoes, withoutdues, in the port at Tampa Town. Thence the iron was transportedby rail to Stones Hill, and about the middle of January thisenormous mass of metal was delivered at its destination.
It will easily be understood that 1,200 furnaces were not toomany to melt simultaneously these 60,000 tons of iron. Each ofthese furnaces contained nearly 140,000 pounds weight of metal.They were all built after the model of those which served forthe casting of the Rodman gun; they were trapezoidal in shape,with a high elliptical arch. These furnaces, constructed offireproof brick, were especially adapted for burning pit coal,with a flat bottom upon which the iron bars were laid. This bottom,inclined at an angle of 25 degrees, allowed the metal to flow intothe receiving troughs; and the 1,200 converging trenches carriedthe molten metal down to the central well.
The day following that on which the works of the masonry andboring had been completed, Barbicane set to work upon thecentral mould. His object now was to raise within the center ofthe well, and with a coincident axis, a cylinder 900 feet high,and nine feet in diameter, which should exactly fill up thespace reserved for the bore of the Columbiad. This cylinder wascomposed of a mixture of clay and sand, with the addition of alittle hay and straw. The space left between the mould and themasonry was intended to be filled up by the molten metal, whichwould thus form the walls six feet in thickness. This cylinder,in order to maintain its equilibrium, had to be bound by ironbands, and firmly fixed at certain intervals by cross-clampsfastened into the stone lining; after the castings these wouldbe buried in the block of metal, leaving no external projection.
This operation was completed on the 8th of July, and the run ofthe metal was fixed for the following day.
"This _fete_ of the casting will be a grand ceremony," said J.T. Maston to his friend Barbicane.
"Undoubtedly," said Barbicane; "but it will not be a public _fete_"
"What! will you not open the gates of the enclosure to all comers?"
"I must be very careful, Maston. The casting of the Columbiadis an extremely delicate, not to say a dangerous operation, andI should prefer its being done privately. At the discharge ofthe projectile, a _fete_ if you like-- till then, no!"
The president was right. The operation involved unforeseendangers, which a great influx of spectators would have hinderedhim from averting. It was necessary to preserve completefreedom of movement. No one was admitted within the enclosureexcept a delegation of members of the Gun Club, who had made thevoyage to Tampa Town. Among these was the brisk Bilsby, TomHunter, Colonel Blomsberry, Major Elphinstone, General Morgan,and the rest of the lot to whom the casting of the Columbiad wasa matter of personal interest. J. T. Maston became their cicerone.He omitted no point of detail; he conducted them throughout themagazines, workshops, through the midst of the engines, andcompelled them to visit the whole 1,200 furnaces one afterthe other. At the end of the twelve-hundredth visit they werepretty well knocked up.
The casting was to take place at twelve o'clock precisely.The previous evening each furnace had been charged with 114,000pounds weight of metal in bars disposed cross-ways to each other,so as to allow the hot air to circulate freely between them.At daybreak the 1,200 chimneys vomited their torrents of flameinto the air, and the ground was agitated with dull tremblings.As many pounds of metal as there were to cast, so many pounds ofcoal were there to burn. Thus there were 68,000 tons of coalwhich projected in the face of the sun a thick curtain of smoke.The heat soon became insupportable within the circle of furnaces,the rumbling of which resembled the rolling of thunder. The powerfulventilators added their continuous blasts and saturated withoxygen the glowing plates. The operation, to be successful,required to be conducted with great rapidity. On a signal givenby a cannon-shot each furnace was to give vent to the molteniron and completely to empty itself. These arrangements made,foremen and workmen waited the preconcerted moment with animpatience mingled with a certain amount of emotion. Not a soulremained within the enclosure. Each superintendent took hispost by the aperture of the run.
Barbicane and his colleagues, perched on a neighboring eminence,assisted at the operation. In front of them was a piece ofartillery ready to give fire on the signal from the engineer.Some minutes before midday the first driblets of metal began toflow; the reservoirs filled little by little; and, by the timethat the whole melting was completely accomplished, it was keptin abeyance for a few minutes in order to facilitate theseparation of foreign substances.
Twelve o'clock struck! A gunshot suddenly pealed forth and shotits flame into the air. Twelve hundred melting-troughs weresimultaneously opened and twelve hundred fiery serpents crepttoward the central well, unrolling their incandescent curves.There, down they plunged with a terrific noise into a depth of900 feet. It was an exciting and a magnificent spectacle.The ground trembled, while these molten waves, launching into thesky their wreaths of smoke, evaporated the moisture of the mouldand hurled it upward through the vent-holes of the stone liningin the form of dense vapor-clouds. These artificial cloudsunrolled their thick spirals to a height of 1,000 yards intothe air. A savage, wandering somewhere beyond the limits of thehorizon, might have believed that some new crater was forming inthe bosom of Florida, although there was neither any eruption,nor typhoon, nor storm, nor struggle of the elements, nor any ofthose terrible phenomena which nature is capable of producing.No, it was man alone who had produced these reddish vapors,these gigantic flames worthy of a volcano itself, thesetremendous vibrations resembling the shock of an earthquake,these reverberations rivaling those of hurricanes and storms;and it was his hand which precipitated into an abyss, dug byhimself, a whole Niagara of molten metal!