“I think so too,” replied Barbicane; “that is why I propose to
quadruple that length, and to construct a gun of nine hundred feet.”
The general and the major offered some objections; nevertheless,
the proposition, actively supported by the secretary, was
definitely adopted.
“But,” said Elphinstone, “what thickness must we give it?”
“A thickness of six feet,” replied Barbicane.
“You surely don’t think of mounting a mass like that upon a
carriage?” asked the major.
“It would be a superb idea, though,” said Maston.
“But impracticable,” replied Barbicane. “No, I think of sinking
this engine in the earth alone, binding it with hoops of wrought
iron, and finally surrounding it with a thick mass of masonry of
stone and cement. The piece once cast, it must be bored with
great precision, so as to preclude any possible windage. So there
will be no loss whatever of gas, and all the expansive force of
the powder will be employed in the propulsion.”
“One simple question,” said Elphinstone: “is our gun to be rifled?”
“No, certainly not,” replied Barbicane; “we require an enormous
initial velocity; and you are well aware that a shot quits a
rifled gun less rapidly than it does a smooth-bore.”
“True,” rejoined the major.
The committee here adjourned for a few minutes to tea and sandwiches.
On the discussion being renewed, “Gentlemen,” said Barbicane,
“we must now take into consideration the metal to be employed.
Our cannon must be possessed of great tenacity, great hardness,
be infusible by heat, indissoluble, and inoxidable by the
corrosive action of acids.”
“There is no doubt about that,” replied the major; “and as we
shall have to employ an immense quantity of metal, we shall not
be at a loss for choice.”
“Well, then,” said Morgan, “I propose the best alloy hitherto
known, which consists of one hundred parts of copper, twelve of
tin, and six of brass.”
“I admit,” replied the president, “that this composition has
yielded excellent results, but in the present case it would be
too expensive, and very difficult to work. I think, then, that
we ought to adopt a material excellent in its way and of low
price, such as cast iron. What is your advice, major?”
“I quite agree with you,” replied Elphinstone.
“In fact,” continued Barbicane, “cast iron costs ten times less
than bronze; it is easy to cast, it runs readily from the moulds
of sand, it is easy of manipulation, it is at once economical of
money and of time. In addition, it is excellent as a material,
and I well remember that during the war, at the siege of
Atlanta, some iron guns fired one thousand rounds at intervals
of twenty minutes without injury.”
“Cast iron is very brittle, though,” replied Morgan.
“Yes, but it possesses great resistance. I will now ask our
worthy secretary to calculate the weight of a cast-iron gun with
a bore of nine feet and a thickness of six feet of metal.”
“In a moment,” replied Maston. Then, dashing off some
algebraical formulae with marvelous facility, in a minute or two
he declared the following result:
“The cannon will weigh 68,040 tons. And, at two cents a pound,
it will cost—-”
“Two million five hundred and ten thousand seven hundred and
one dollars.”
Maston, the major, and the general regarded Barbicane with
uneasy looks.
“Well, gentlemen,” replied the president, “I repeat what I
said yesterday. Make yourselves easy; the millions will not
be wanting.”
With this assurance of their president the committee separated,
after having fixed their third meeting for the following evening.
CHAPTER IX
THE QUESTION OF THE POWDERS
There remained for consideration merely the question of powders.
The public awaited with interest its final decision. The size
of the projectile, the length of the cannon being settled, what
would be the quantity of powder necessary to produce impulsion?
It is generally asserted that gunpowder was invented in the
fourteenth century by the monk Schwartz, who paid for his grand
discovery with his life. It is, however, pretty well proved
that this story ought to be ranked among the legends of the
middle ages. Gunpowder was not invented by any one; it was the
lineal successor of the Greek fire, which, like itself, was