minutes before midday
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 .