THE FETE OF THE CASTING
During the eight months which were employed in the work of excavation
the preparatory works of the casting had been carried on simultaneously
with extreme rapidity. A stranger arriving at Stones Hill would have
been surprised at the spectacle offered to his view.
At 600 yards from the well, and circularly arranged around it as a
central point, rose 1,200 reverberating ovens, each six feet in
diameter, and separated from each other by an interval of three feet.
The circumference occupied by these 1,200 ovens presented a length of
two miles. Being all constructed 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 had
decided 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
moulding operations; and when smelted with pit coal, is of superior
quality for all 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 rarely
sufficiently homogeneous; and it requires a second fusion completely to
refine it by dispossessing it of its last earthly deposits. So long
before being forwarded to Tampa Town, the iron ore, molten in the great
furnaces of Coldspring, and brought into contact with coal and silicium
heated to a high temperature, 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, a quantity
far too costly to send by railway. The cost of transport would have
been double that of material. It appeared preferable to freight vessels
at New York, and to load them with the iron in bars. This, however,
required not less than sixty- eight vessels of 1,000 tons, a veritable
fleet, which, quitting New York on the 3rd of May, on the 10th of the
same month ascended the Bay of Espiritu Santo, and discharged their
cargoes, without dues, in the port at Tampa Town. Thence the iron was
transported by rail to Stones Hill, and about the middle of January
this enormous mass of metal was delivered at its destination.
It will easily be understood that 1,200 furnaces were not too many to
melt simultaneously these 60,000 tons of iron. Each of these furnaces
contained nearly 140,000 pounds weight of metal. They were all built
after the model of those which served for the casting of the Rodman
gun; they were trapezoidal in shape, with a high elliptical arch. These
furnaces, constructed of fireproof 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 into the receiving troughs; and the 1,200 converging
trenches carried the molten metal down to the central well.
The day following that on which the works of the masonry and boring had
been completed, Barbicane set to work upon the central mould. His
object now was to raise within the center of the well, and with a
coincident axis, a cylinder 900 feet high, and nine feet in diameter,
which should exactly fill up the space reserved for the bore of the
Columbiad. This cylinder was composed of a mixture of clay and sand,
with the addition of a little hay and straw. The space left between the
mould and the masonry was intended to be filled up by the molten metal,
which would thus form the walls six feet in thickness. This cylinder,
in order to maintain its equilibrium, had to be bound by iron bands,
and firmly fixed at certain intervals by cross-clamps fastened into the
stone lining; after the castings these would be buried in the block of
metal, leaving no external projection.
This operation was completed on the 8th of July, and the run of the
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 Columbiad is an
extremely delicate, not to say a dangerous operation, and I should
prefer its being done privately. At the discharge of the projectile, a
_fete_ if you like—till then, no!”
The president was right. The operation involved unforeseen dangers,
which a great influx of spectators would have hindered him from
averting. It was necessary to preserve complete freedom of movement. No
one was admitted within 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, and the rest of the lot to whom the casting of the
Columbiad was a matter of personal interest. J. T. Maston became their
cicerone. He omitted no point of detail; he conducted them throughout
the magazines, workshops, through the midst of the engines, and
compelled them to visit the whole 1,200 furnaces one after the other.
At the end of the twelve-hundredth visit they were pretty well knocked
up.
The casting was to take place at twelve o’clock precisely. The previous
evening each furnace had been charged with 114,000 pounds 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 flame into the air, and the ground was
agitated with dull tremblings. As many pounds of metal as there were to
cast, so many pounds of coal were there to burn. Thus there were 68,000
tons of coal which 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
powerful ventilators added their continuous blasts and saturated with
oxygen the glowing plates. The operation, 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 the molten iron and completely to
empty itself. These arrangements made, foremen and workmen waited the
preconcerted moment with an impatience mingled with a certain amount of
emotion. Not a soul remained within the enclosure. Each superintendent
took his post 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 of artillery
ready to give fire on the signal from the engineer. Some minutes before
midday the first driblets of metal began to flow; the reservoirs filled
little by little; and, by the time that the whole melting was
completely accomplished, it was kept in abeyance for a few minutes in
order to facilitate the separation of foreign substances.
Twelve o’clock struck! A gunshot suddenly pealed forth and shot its
flame into the air. Twelve hundred melting-troughs were simultaneously
opened and twelve hundred fiery serpents crept toward the central well,
unrolling their incandescent curves. There, down they plunged with a
terrific noise into a depth of 900 feet. It was an exciting and a
magnificent spectacle. The ground trembled, while these molten waves,
launching into the sky their wreaths of smoke, evaporated the moisture
of the mould and hurled it upward through the vent-holes of the stone
lining in the form of dense vapor-clouds. These artificial clouds
unrolled their thick spirals to a height of 1,000 yards into the air. A
savage, wandering somewhere beyond the limits of the horizon, might
have believed that some new crater was forming in the bosom of Florida,
although there was neither any eruption, nor typhoon, nor storm, nor
struggle of the elements, nor any of those 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,
these tremendous 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 by himself, a whole
Niagara of molten metal!