Chapter 7 Chapter Seven: The Hymn of the Cannonball

The Cambridge Observatory, in its historic reply of October 7, had dealt with the problem astronomically; now it had to be solved mechanically.In any country other than the United States, these specific difficulties seem insurmountable.Here, it's just a game. Chairman Barbicane wasted no time in calling a meeting of the executive committee at the Gun Club.They had to figure out the three important problems of cannon, shells and powder during the three sessions.The executive committee consisted of four of the most learned scientists in this field, namely: Barbicane (who had the right to vote in the event of an equality of votes for and against), General Morgan, and Elfeston, the staff officer, There was also Maston, who was indispensable to any meeting, who acted as secretary and was responsible for the minutes of the meeting.

On October 8, the Committee met at Chairman Barbican's house at 3 Rue de la République.Lest cries of hunger disturb such a serious debate, which was so important, the four members of the Cannon Club sat down around a table with a pile of sandwiches and some rather large teapots.Maston immediately spun the pen on his hook, and the meeting began. Barbicane spoke first: "Dear members," said he, "we have now to settle one of the most important problems of ballistics, that great science which is concerned exclusively with the motion of projectiles, that is to say, with objects thrown into the air by a propelling force." The movement that makes it go forward naturally."

"Ah! Ballistics! Ballistics!" cried Maston in an excited voice. "It seems more logical, then, if our first meeting had been to discuss mechanics," went on Barbicane. . . . "Yes," echoed General Morgan. "However, after careful consideration," continued Barbicane, "I feel that the problem of the ball should be placed before the cannon, and that the size of the latter should be determined by the size of the former." "I ask for the floor," Maston said loudly. His request was granted immediately, and indeed, his glorious past deserved such treatment.

"Fair friends," he said in inspired tones, "our Chairman is right to put the cannonball first! The cannonball we are going to send to the moon is our emissary. , our Ambassador, allow me to speak from a purely ethical point of view." This novel view of the cannonball aroused the strong curiosity of the various committee members, so they listened to Secretary Maston's speech with special attention. "Dear members," he said, "I will only talk briefly, I will temporarily abandon the point of view of physics, and put aside the murderous shells, and talk first from the point of view of mathematics and ethics. Cannonballs. I think cannonballs are the most glorious manifestation of human power. All the power of human beings is expressed in a single cannonball. Humans created it, which shows that human beings are almost the same as creators!"

"Excellent!" said Al Pheston, the staff officer. "The fact," exclaimed the orator, "that heaven created the stars and planets, and man created the cannonball, is a sign of the highest speed man can attain, and that this is a concrete and minute celestial body, and indeed a celestial body is nothing more than It’s just some cannonballs roaming in the sky! The speed of electricity, the speed of light, the speed of stars, the speed of accumulating stars, the speed of planets, the speed of satellites, the speed of sound, and the speed of wind belong to God! But it belongs to us But the speed of the cannonball is a hundred times faster than the train and the fastest horse!"

Maston, in his lyrical voice, sang the hymn of the cannonball ecstatically. "Would you like to see figures?" he went on. "There are convincing figures here! Take the humble twenty-four-pound shell, though it is 800,000 times slower than electricity and 600 times slower than light." It is forty times slower than the earth orbiting the sun and seventy-six times slower, but as soon as it leaves the cannon, it exceeds the speed of sound, traveling two hundred Torvalds per second, and two thousand Torvalds in ten seconds 14 miles per minute, 840 miles per hour, 20,000 miles per day, or 7,336,500 miles per year at the speed of the earth's rotation at the equator ...so it only takes eleven days to reach the moon, twelve years to the sun, and three hundred and sixty years to reach Neptune at the edge of the solar system. Voila!

This is what this humble cannonball created by our hands can do: what can it do if we multiply this velocity twenty times; and fire it at seven miles per second!what!Noble shells, magnificent shells!How I like to imagine how you are entertained up there with the honor befitting an ambassadorship of the Earth! " The eloquent concluding remarks were greeted with a burst of "Ulla", and the excited Maston sat down amidst the congratulations of his companions. "We have been working on poetry for a long time," said Barbicane, "now let us go directly to the problem."

"We're ready," replied the members of the executive committee, after each swallowed half a dozen sandwiches. "You already know what problem awaits us," continued the chairman, "that we must give the ball a velocity of twelve thousand yards per second. I have reason to believe that we can succeed. But let us examine for the time being until today." At the speed we have gained so far, General Morgan can supply us with the material." "It couldn't be easier," replied the General, "for I was a member of the Experimental Committee in time of war. I can therefore tell you that the range of a hundred-pounder Dougling's shell is twenty-five hundred Torvalds." , with a muzzle velocity of five hundred yards per second."

"Very well. Where's Rodman's Columbia?" the chairman asked. "Rodman's Columbia once tested a cannon at the Hamilton Fort near New York. A cannonball fired weighed half a ton, with a range of 6,000 Torvalds and a speed of 800 yards per second. British Ames Strong and Barry Sai has never achieved such a result." "Hey! Englishman!" Maston snorted, stretching his dreadful iron hook toward the eastern horizon. "So," said Barbicane, "eight hundred yards is the maximum speed achievable hitherto—"Yes," replied Morgan. "If my mortar hadn't exploded," said Maston, "I could say..."

"Yes, but it has exploded," replied Barbicane, with a kind gesture. "Then we shall start with a speed of eight hundred yards. It must be enlarged twenty times. Therefore, as to the method by which such speeds are to be produced, we shall leave it to another meeting, and I would like to draw your attention, my dears. Members, it is the proper size of the shell. You can naturally expect that the shell that is to be studied now is not the kind of shell that weighs no more than half a ton!" "Why not?" asked the staff officer. "Because," replied Maston, pointing his gun, "the cannonball would have to be quite large to attract the attention of the Lunarians, if there were any men on the Moon."

"Yes," said Barbicane, "there is another and more important reason." "What do you mean by that, Barbicane?" asked the officer. "I mean it's not enough to fire a shell and forget about it, we should keep an eye on it until it reaches its destination." "Ah?" The general and the staff officer responded at the same time, they were quite surprised by this proposal. "Undoubtedly," continued Barbicane, in the tone of a man of great self-confidence, without doubt, otherwise our experiments would have come to nothing. " Then," the staff officer asked closely, "do you want to build an extremely large cannonball? " "No. Listen to me. You know that optical instruments have reached a level of sophistication, and some telescopes are capable of magnifying objects six thousand times and reducing the distance to the moon to about forty miles. But, at this Objects at a distance of sixty feet can only be seen at a distance of sixty feet. We have not enlarged the observation power of the telescope, because any further enlargement would impair the luminosity of the object, and the moon is only a reflector, so it is impossible to Emit more intense light, so the magnification cannot exceed the current limit." "So! What are you going to do?" asked the general. "Do you want your shells to be sixty feet in diameter?" "No!" "You want to make the moon brighter?" "Exactly." "This is too much!" exclaimed Maston. "Yes, very simply," answered Barbicane. "Actually, if I can reduce the thickness of the atmosphere that the moon passes through, wouldn't that be the same as making the moon brighter?" "That's obvious." "Excellent! Just build a telescope on a high mountain to get this effect. We're going to do that." "I see, I see," replied the staff officer. "You're good at simplifying things.... How much would you like to magnify the Moon this way?" "Forty-eight thousand times, this reduces the distance to the moon to only five miles, and objects need only be nine feet in diameter to be seen clearly." "Excellent!" cried Maston. "Shall our shells be nine feet in diameter?" "Completely correct." "However, allow me to say to you," said Chief of Staff Al Felston, "that the weight is still..." "Ah: staff," replied Barbicane, "before discussing its weight, let me tell you that our ancestors have done wonderful things in this respect) Not that I think ballistics has not What progress, however, it would be good for us to know that the Middle Ages had achieved astonishing, I dare say, more astonishing achievements than our own works." "No!" Morgan retorted. "Please confirm your statement," followed Maston. "Nothing could be easier," replied Barbicane, "and I have many examples in support of my proposal. For example, in 1543, during the reign of Mehmed II, at Constantinople The stone balls used weighed nineteen hundred pounds and were naturally quite large." "Ah! ah!" said the officer, "nineteen hundred pounds, that is a remarkable figure!" "In the days of chivalry, in the fortress of St. Elma, on the Isle of Malta, a cannon fired a ball weighing twenty-five hundred pounds." "impossible!" "Finally, according to French historians, in the time of Louis XI, a mortar fired a ball weighing only five hundred pounds; Down to the place where the sages keep the lunatics—Charenton." "Excellent!" said Maston. "Then what did we see? The Ames Strong fired five hundred pound shells, and Rodman's Columbia fired half a ton shells! It seems that the range of the shells has increased, but their weight has decreased Yes. If we put a little effort into this, by the progress of science, we might increase the weight of the shells of Mohammed II and the horsemen of Malta tenfold." "That's obvious," said the staff officer, "but what metal are you going to make your shells from?" "It's simple, cast iron," said General Morgan. "Hey! Cast iron!" cried Maston, with an air of contempt. "That's pretty tacky for a cannonball destined to go to the moon." "Don't exaggerate, my dear friend, cast iron will suffice." "Well!" said Chief of Staff Winfeston, "since weight is directly proportional to volume, a cast-iron cannonball ... even if it is only nine feet in diameter, is still terribly heavy!" "Yes; solid cannonballs are naturally heavy, but hollow ones are different," said Barbicane. "Hollow! Is that still a cannonball?" "We can put some letters and samples of land trade in it!" Maston retorted. "Yes, it is such a shot," replied Barbicane, "and it must be. A solid shot of 108 inches weighs more than two hundred thousand pounds, which is obviously too heavy." , however, to keep the shell constant: For stability, I propose to give it a weight of twenty thousand pounds. " "How thick is the wall?" the staff officer asked. "If we obey the general laws of proportion," said General Morgan, two shells 108 inches in diameter would require walls at least two feet thick. " "This is too thick," said Barbicane. "Please note that we are not talking about shells drilled in steel plates, so the thickness of the shell wall is enough to resist the pressure of the gas of the gunpowder. Now here is the problem: How thick-walled a lowly bullet weighs only twenty thousand pounds? Our able calculator, the honest Maston, will give us the answer on the spot." "It can't be easier," replied the venerable secretary of the executive committee. While talking, he drew a few geometric formulas on the paper, and he could see several beats and the second power of X appeared in his pen.Without even touching it, he drew a cube root and said: "The wall is no more than two inches thick." "Is this thick enough?" the staff officer asked suspiciously. "Not enough," replied Chairman Barbicane, "apparently not enough." "So, what to do?" Alfeston said with a troubled look. "Use another metal. "Is copper okay?" Morgan asked. "No, it's too heavy. I suggest you use a better metal." "Use what?" the staff officer asked. "Aluminum," answered Barbicane. "Al!" cried the Chairman's three companions together. "There is no doubt, my friends. You all know that in 1854 a famous French chemist, Henri Saint-Cruel-Daviere, extracted fine-grained aluminum. This precious metal is like silver. As natural, as permanent as gold, as strong as iron, as easy to melt as copper, as light as glass, this metal is easy to refine and widely distributed in nature, because alum is the composition of most rocks The foundation, which is three times lighter than iron, seems to have been created by nature to provide us with matter for making cannonballs." "Oh, Al!" exclaimed the secretary of the executive committee, who was always noisy when he was excited. "But, dear Chairman," asked the staff officer, "won't aluminum bombs be too expensive to manufacture?" "At the time of its discovery," replied Barbicane, "aluminium was worth two hundred and sixty to two hundred and eighty dollars a pound; then it fell to twenty-seven dollars, and at last, to this day, it is only worth nine dollars. " "Even if it's nine dollars per pound," the staff didn't make any concessions, and it's not easy to do. The price is still very high! " "Yes, my dear staff, but it is not impossible." "How much should the shell weigh?" Morgan asked. "The result of my calculations," replied Barbicane, "is that a cast-iron ball, one hundred and eight inches in diameter and twelve inches thick, weighs sixty-seven thousand four hundred and forty pounds, if made of aluminium, That's only 19,250 pounds." "Excellent!" exclaimed Maston. "Look! Just what we want." "Excellent! Excellent!" objected the staff officer, "but don't you know that at nine dollars a pound for aluminum, this shell is worth..." "One hundred and seventy-three thousand two hundred and fifty dollars, I know that very well; but don't worry, my friends, I can assure you that our cause will not be short of money." "It's going to rain down on our coffers!" Maston sarcastically said. "So, what's your opinion on aluminum bombs?" asked the chairman. "Decided to adopt," the three committee members replied together. "The shape of the ball is not very important," went on Barbicane, "since it reaches the vacuum as soon as it passes through the atmosphere, I propose to make a round ball, so that it will do so, if it pleases to spin." . " The first meeting of the executive committee was thus concluded, the shell problem officially settled, and Maston felt complacent at the thought of sending an aluminum shell to the moonmen, "Let them know that the inhabitants of the earth are great!"