There were as many pounds of coal to be burnt as metal to be melted.

There were, therefore, 68,000 tons of coal throwing up before the sun a thick curtain of black smoke.
The heat soon became unbearable in the circle of furnaces, the rambling of which resembled the rolling of thunder; powerful bellows added their continuous blasts, and saturated the incandescent furnaces with oxygen.
The operation of casting in order to succeed must be done rapidly.

At a signal given by a cannon-shot each furnace was to pour out the liquid iron and to be entirely emptied.
These arrangements made, foremen and workmen awaited the preconcerted moment with impatience mixed with emotion.

There was no longer any one in the inclosure, and each superintendent took his place near the aperture of the run.
Barbicane and his colleagues, installed on a neighbouring eminence, assisted at the operation.

Before them a cannon was planted ready to be fired as a sign from the engineer.
A few minutes before twelve the first drops of metal began to run; the reservoirs were gradually filled, and when the iron was all in a liquid state it was left quiet for some instants in order to facilitate the separation of foreign substances.
Twelve o'clock struck.