From the Earth to the Moon by Jules Verne

high degree of brisance and eventually damages a gun’s bore.”
    “That’s a drawback for a cannon meant for long use, but not for our Columbiad. We’ll run no risk of a burst barrel, and the powder will have to ignite very quickly, so that its energy will be completely utilized.”
    “We could make several priming holes,” said J. T. Maston, “and ignite the powder at different places simultaneously.”
    “I suppose so,” replied the major, “but that would make the operation more difficult. I’ll stick to my coarse-grained powder because it will eliminate such difficulties.”
    “So be it,” said the general.
    “In his Columbiad,” said the major, “Rodman used a powder with grains the size of chestnuts, made of willowcharcoal that was simply roasted in iron boilers. It was hard and glossy, left no trace on the hand, contained a high proportion of hydrogen and oxygen, burned instantaneously, and, despite its great brisance, it wasn’t hard on gun barrels.”
    “Then I don’t see any reason to hesitate,” said J. T. Maston. “Our choice is clear.”
    “Unless you’d prefer gold powder,” said the major, laughing. This earned him a threatening gesture from his touchy friend’s iron hook.
    So far Barbicane had remained aloof from the discussion. He had been merely listening and letting the others talk. It was obvious that he had an idea. He contented himself with saying:
    “And now, my friends, what quantity of powder do you propose?”
    His three colleagues looked at one another for a few moments. Finally the general said, “Two hundred thousand pounds.”
    “Five hundred thousand,” said the major.
    “Eight hundred thousand pounds!” said J. T. Maston.
    This time the major could not accuse him of exaggerating. After all, they were planning to send a 20,000-pound projectile to the moon with an initial velocity of 36,000 feet per second. There was a silence after the three men had made their respective proposals.
    It was finally broken by Barbicane:
    “Gentlemen,” he said calmly, “I start from the principle that the strength of our cannon, built correctly, will be unlimited. I’m therefore going to surprise Mr. Maston by proposing to double his 800,000 pounds of powder.”
    “A million six hundred thousand pounds?” said J. T. Maston, bounding on his chair.
    “Yes.”
    “But then we’ll have to come back to my half-mile cannon!”
    “That’s obvious,” said the major.
    “A million six hundred thousand pounds of powder,” said J. T. Maston, “will occupy a volume of about 22,000 cubic feet. Since your cannon has a capacity of only 54,000 cubic feet, it will be half full, and the bore will be so short that the expanding gases won’t be able to give the projectile enough velocity.”
    There was no answer to that. J. T. Maston had spoken the truth. They all looked at Barbicane.
    “Nevertheless,” he said, “I insist on using that much powder. Think of it: 1,600,000 pounds of powder will produce 2,500,000 cubic feet of gas. Two and a half million! Do you realize what that means?”
    “But how can we do it?” asked the general.
    “It’s quite simple: we must reduce that enormous mass of powder without diminishing its power.”
    “Very well, but how?”
    “I’ll tell you,” Barbicane said simply. The others stared at him eagerly. “Nothing could be simpler than to reduce that amount of powder to a quarter of its normal volume. You’re all familiar with that singular substance which forms the elementary tissues of plants and is known as cellulose.”
    “Ah, now I understand you!” said the major.
    “It can be obtained in a pure state from various sources,” Barbicane went on, “especially cotton, which is the fiber that surrounds the seeds of the cotton plant. When cotton is combined with cold nitric acid, it’s transformed into a substance that’s extremely insoluble, combustible, and explosive. It was discovered over thirty years ago, in 1832, by a French chemist