"I give it up," answered the major. "You have such a way of simplifying things. And what enlargement do you expect to obtain in this way?"
"One of 48,000 times, which should bring the moon within an apparent distance of five miles; and, in order to be visible, objects need not have a diameter of more than nine feet."
"So, then," cried J. T. Maston, "our projectile need not be more than nine feet in diameter."
"Let me observe, however," interrupted Major Elphinstone, "this will involve a weight such as—"
"My dear major," replied Barbicane, "before discussing its weight, permit me to enumerate some of the marvels which our ancestors have achieved in this respect. I don't mean to pretend that the science of gunnery has not advanced, but it is as well to bear in mind that during the middle ages they obtained results more surprising, I will venture to say, than ours. For instance, during the siege of Constantinople by Mahomet II., in 1453, stone shot of 1900 lbs. weight were employed. At Malta, in the time of the knights, there was a gun of the fortress of St. Elmo which threw a projectile weighing 2500 lbs. And, now, what is the extent of what we have seen ourselves? Armstrong guns discharging shot of 500 lbs., and the Rodman guns projectiles of half a ton! It seems, then, that if projectiles have gained in range, they have lost far more in weight. Now, if we turn our efforts in that direction, we ought to arrive, with the progress of science, at ten times the weight of the shot of Mahomet II. and the Knights of Malta."
CANNON AT MALTA IN THE TIME OF THE KNIGHTS.
"Clearly," replied the major; "but what metal do you calculate upon employing?"
"Simply cast iron," said General Morgan.
"But," interrupted the major, "since the weight of a shot is proportionate to its volume, an iron ball of nine feet in diameter would be of tremendous weight."