The cannon was suddenly fired, and shot its flame into the air.

Twelve hundred tapping-holes were opened simultaneously, and twelve hundred fiery serpents crept along twelve hundred troughs towards the central well, rolling in rings of fire.

There they plunged with terrific noise down a depth of 900 feet.

It was an exciting and magnificent spectacle.

The ground trembled, whilst these waves of iron, throwing into the sky their clouds of smoke, evaporated at the same time the humidity of the mould, and hurled it upwards through the vent-holes of the masonry in the form of impenetrable vapour.