“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.
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, have been transformed into detonating
mixtures.
But if learned men know perfectly the false history
of gunpowder, few people are aware of its mechanical
power. Now this is necessary to be known in order
to understand the importance of the question submitted
to the committee.
Thus a litre of gunpowder weighs about 2 lbs.; it
produces, by burning, about 400 litres of gas; this
gas, liberated, and under the action of a temperature
of 2,400 deg., occupies the space of 4,000 litres.
Therefore the volume of powder is to the volume of
gas produced by its deflagration as 1 to 400.
The frightful force of this gas, when it is compressed
into a space 4,000 times too small, may be imagined.
This is what the members of the committee knew perfectly
when, the next day, they began their sitting.
Major Elphinstone opened the debate.
“My dear comrades,” said the distinguished
chemist, “I am going to begin with some unexceptionable
figures, which will serve as a basis for our calculation.
The 24-lb. cannon-ball, of which the Hon. J.T.
Maston spoke the day before yesterday, is driven out
of the cannon by 16 lbs. of powder only.”
