by Jules Verne
CHAPTER XV.
THE FETE OF THE CASTING.
During the eight months which were employed in the work of excavationthe preparatory works of the casting had been carried on simultaneouslywith extreme rapidity. A stranger arriving at Stones Hill would have beensurprised at the spectacle offered to his view.
At 600 yards from the well, and circularly arranged around it as a centralpoint, rose 1200 reverberating ovens, each six feet in diameter, andseparated from each other by an interval of three feet. The circumferenceoccupied by these 1200 ovens presented a length of two miles. Being allconstructed on the same plan, each with its high quadrangular chimney,they produced a most singular effect.
It will be remembered that on their third meeting the Committee haddecided to use cast-iron for the Columbiad, and in particular the _white_description. This metal in fact is the most tenacious, the most ductile,and the most malleable, and consequently suitable for all mouldingoperations; and when smelted with pit coal, is of superior quality forall engineering works requiring great resisting power, such as cannon,steam-boilers, hydraulic presses, and the like.
Cast-iron, however, if subjected to only one single fusion, is rarelysufficiently homogeneous; and it requires a second fusion completely torefine it by dispossessing it of its last earthly deposits. So beforebeing forwarded to Tampa Town, the iron ore, molten in the great furnacesof Coldspring, and brought into contact with coal and silicium heated toa high temperature, was carburized and transformed into cast-iron. Afterthis first operation, the metal was sent on to Stones Hill. They had,however, to deal with 136,000,000 lbs. of iron, a quantity far too costlyto send by railway. The cost of transport would have been double that ofmaterial. It appeared preferable to freight vessels at New York, and toload them with the iron in bars. This, however, required not less thansixty-eight vessels of 1000 tons, a veritable fleet, which, quitting NewYork on the 3rd of May, on the 10th of the same month ascended the Bayof Espiritu Santo, and discharged their cargoes, without dues, in theport at Tampa Town. Thence the iron was transported by rail to StonesHill, and about the middle of January this enormous mass of metal wasdelivered at its destination.
It will be easily understood that 1200 furnaces were not too many tomelt simultaneously these 60,000 tons of iron. Each of these furnacescontained nearly 140,000 lbs. weight of metal. They were all built afterthe model of those which served for the casting of the Rodman gun, theywere trapezoidal in shape, with a high elliptical arch. These furnaces,constructed of fireproof brick, were especially adapted for burningpit coal, with a flat bottom upon which the iron bars were laid. Thisbottom, inclined at an angle of 25 deg., allowed the metal to flow intothe receiving troughs; and the 1200 converging trenches carried themolten metal down to the central well.
The day following that on which the works of the masonry and boring hadbeen completed, Barbicane set to work upon the central mould. His objectnow was to raise within the centre of the well, and with a coincidentaxis, a cylinder 900 feet high, and 9 feet in diameter, which shouldexactly fill up the space reserved for the bore of the Columbiad. Thiscylinder was composed of a mixture of clay and sand, with the addition ofa little hay and straw. The space left between the mould and the masonrywas intended to be filled up by the molten metal, which would thus formthe walls six feet in thickness. This cylinder, in order to maintain itsequilibrium, had to be bound by iron bands, and firmly fixed at certainintervals by cross-clamps fastened into the stone lining; after thecastings these would be buried in the block of metal, leaving no externalprojection.
Illustration: THE CASTING.
This operation was completed on the 8th of July, and the run of the metalwas fixed for the following day.
"This fete of the casting will be a grand ceremony," said J. T. Mastonto 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 Columbiad is anextremely delicate, not to say a dangerous operation, and I should preferits being done privately. At the discharge of the projectile, a fete ifyou like--till then, no!"
The president was right. The operation involved unforeseen dangers, whicha great influx of spectators would have hindered him from averting. It wasnecessary to preserve complete freedom of movement. No one was admittedwithin the enclosure except a delegation of members of the Gun Club,who had made the voyage to Tampa Town. Among these was the brisk Bilsby,Tom Hunter, Colonel Blomsberry, Major Elphinstone, General Morgan, andthe rest of the lot to whom the casting of the Columbiad was a matterof personal interest. J. T. Maston became their cicerone. He omitted nopoint of detail; he conducted them throughout the magazines, workshops,through the midst of the engines, and compelled them to visit the whole1200 furnaces one after the other. At the end of the twelve-hundredthvisit they were pretty well knocked up.
The casting was to take place at 12 o'clock precisely. The previousevening each furnace had been charged with 114,000 lbs. weight of metalin bars disposed cross-ways to each other, so as to allow the hot airto circulate freely between them. At daybreak the 1200 chimneys vomitedtheir torrents of flame into the air, and the ground was agitated withdull tremblings. As many pounds of metal as there were to _cast_, so manypounds of coal 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 heatsoon became insupportable within the circle of furnaces, the rumbling ofwhich resembled the rolling of thunder. The powerful ventilators addedtheir continuous blasts and saturated with oxygen the glowing plates. Theoperation, to be successful, required to be conducted with great rapidity.On a signal given by a cannon-shot each furnace was to give vent to themolten iron and completely to empty itself. These arrangements made,foremen and workmen waited the preconcerted moment with an impatiencemingled with a certain amount of emotion. Not a soul remained within theenclosure. Each superintendent took his post by the aperture of the run.
Barbicane and his colleagues, perched on a neighbouring eminence,assisted at the operation. In front of them was a piece of artilleryready to give fire on the signal from the engineer. Some minutes beforemidday the first driblets of metal began to flow; the reservoirs filledlittle by little; and, by the time that the whole melting was completelyaccomplished, it was kept in abeyance for a few minutes in order tofacilitate the separation of foreign substances.
Twelve o'clock struck! A gunshot suddenly pealed forth and shot itsflame into the air. Twelve hundred melting-troughs were simultaneouslyopened and twelve hundred fiery serpents crept towards the centralwell, unrolling their incandescent curves. There, down they plungedwith a terrific noise into a depth of 900 feet. It was an exciting anda magnificent spectacle. The ground trembled, while these molten waves,launching into the sky their wreaths of smoke, evaporated the moistureof the mould and hurled it upwards through the vent-holes of the stonelining in the form of dense vapour-clouds. These artificial cloudsunrolled their thick spirals to a height of 1000 yards into the air.A savage, wandering somewhere beyond the limits of the horizon, mighthave believed that some new crater was forming in the bosom of Florida,although there was neither any eruption, nor typhoon, nor storm, norstruggle of the elements, nor any of those terrible phenomena whichnature is capable of producing. No, it was man alone who had producedthese reddish vapours, these gigantic flames worthy of a volcano itself,these tremendous vibrations resembling the shock of an earthquake, thesereverberations rivalling those of hurricanes and storms; and it was hishand which precipitated into an abyss, dug by himself, a whole Niagaraof molten metal!