Free From the Earth to the Moon by Jules Verne Page B

evening.

CHAPTER 9

THE QUESTION OF POWDER
    T HE QUESTION of powder still had to be dealt with. The public was eagerly awaiting this final decision. Now that the respective sizes of the projectile and the cannon had been established, how much gunpowder would be needed to provide the necessary propulsion? That formidable substance, which man had succeeded in bringing under his control, would have to be used in unheard-of amounts.
    It is generally known and often repeated that gunpowder was invented in the fourteenth century by a monk named Schwarz, who paid for his great discovery with his life. But it has now been almost certainly proven that this story must be classified as a medieval legend. Gunpowder was invented by no one. It is directly descended from “Greek fire,” which, like it, is composed of sulfur and saltpeter; but in the course of time those deflagrating mixtures were transformed into explosive ones.
    But while the learned are perfectly familiar with the false history of gunpowder, few people realize its mechanical power. This must be known in order to understand the importance of the question under consideration by the committee.
    A quart of gunpowder weighs about two pounds. When it burns, it produces 400 quarts of gas. When thisgas is released, under the effect of a temperature of 2,400 degrees, it occupies a volume of 4,000 quarts. Thus the ratio between a certain volume of gunpowder and the volume of gas it produces when it burns is 4,000 to one. It is not difficult to imagine the awesome power of that gas when it is confined in a space 4,000 times too small for it.
    The members of the committee were well aware of this when they began their third meeting. Barbicane gave the floor to Major Elphiston, who had been in charge of powder production during the war.
    “Gentlemen,” said the distinguished chemist, “I’ll begin by giving you some undeniable figures that we can use as a basis for discussion. The twenty-four-pounder, which our honorable secretary spoke about so poetically the day before yesterday, uses only sixteen pounds of powder to fire its ball.”
    “Are you sure of that figure?” asked Barbicane.
    “Quite sure. The Armstrong cannon uses only seventy-five pounds of powder for its 800-pound projectile, and the Rodman Columbiad uses only 160 pounds of powder to shoot its half-ton projectile a distance of six miles. These facts are incontestable, because I personally gathered them from the reports of the Artillery Committee.”
    “That’s perfectly true,” said the general.
    “Here’s the conclusion to be drawn from these figures,” said the major: “the quantity of powder doesn’t increase in direct proportion to the weight of the projectile. The twenty-four-pounder uses sixteen pounds of powder, or two-thirds the weight of its projectile, but that ratio isn’t constant.
    “If it were, a projectile weighing half a ton would require 667 pounds of powder, but it actually requires only 160 pounds.”
    “What point are you trying to make?” asked Barbicane.
    “If you carry your theory to its logical conclusion, Major,” said J. T. Maston, “you’ll have to maintain that when the projectile becomes heavy enough, it won’t need any powder at all!”
    “You’re playful even in the midst of a serious discussion, Maston,” said the major, “but don’t worry: I’ll soon propose a quantity of powder that will satisfy your honor as an artilleryman. I do want to point out, however, that after experiments made during the war the powder charge for the biggest cannons was reduced to a tenth of the weight of their projectiles.”
    “That’s also perfectly true,” said the general. “But before we decide on the amount of powder necessary to propel our projectile, I think we’d better agree on what kind of powder we’ll use.”
    “We’ll use coarse-grained powder,” said the major. “It burns faster than fine-grained powder.”
    “Yes,” said the general, “but it has a