"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.