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,