ch as cast-iron. Is not that your opinion, major?"

"Quite," answered Elphinstone.

"In fact," resumed Barbicane, "cast-iron costs ten times less than
bronze; it is easily melted, it is readily run into sand moulds, and is
rapidly manipulated; it is, therefore, an economy of money and time.
Besides, that material is excellent, and I remember that during the war
at the siege of Atlanta cast-iron cannon fired a thousand shots each
every twenty minutes without being damaged by it."

"Yet cast-iron is very brittle," answered Morgan.

"Yes, but it possesses resistance too. Besides, we shall not let it
explode, I can answer for that."

"It is possible to explode and yet be honest," replied J.T. Maston
sententiously.

"Evidently," answered Barbicane. "I am, therefore, going to beg our
worthy secretary to calculate the weight of a cast-iron cannon 900 feet
long, with an inner diameter of nine feet, and sides six feet thick."

"At once," answered J.T. Maston, and, as he had done the day before, he
made his calculations with marvellous facility, and said at the end of a
minute--

"This cannon will weigh 68,040 tons."

"And how much will that cost at two cents a pound?"

"Two million five hundred and ten thousand seven hundred and one
dollars."

J.T. Maston, the major, and the general looked at Barbicane anxiously.

"Well, gentlemen," said the president, "I can only repeat what I said to
you yesterday, don't be uneasy; we shall not want for money."

Upon this assurance of its president the committee broke up, after
having fixed a third meeting for the next evening.

CHAPTER IX.

THE QUESTION OF POWDERS.

The question of powder still remained to be settled. The public awaited
this last decision with anxiety. The size of the projectile and length
of the cannon being given, what would be the quantity of powder
necessary to produce the impulsion? This terrible agent, of which,
however, man has made himself master, was destined to play a part in
unusual proportions.

It is generally known and often asserted that gunpowder was invented in
the fourteenth century by the monk Schwartz, who paid for his great
discovery with his life. But it is nearly proved now that this story
must be ranked among the legends of the Middle Ages. Gunpowder was
invented by no one; it is a direct product of Greek fire, composed, like
it, of sulphur and saltpetre; only since that epoch these mixtures;
which were only dissolving, ha