The Physics of War (19 page)

One of the most interesting rifles of this era was the Sharps, invented by Christian Sharps in 1848. But again it saw only limited use in the war, mostly by marksman, or snipers. One of the main problems was that it was quite expensive—three times the cost of the Springfield. The Sharps got a lot of attention after the 1990 movie
Quigley Down Under
, in which Matt Quigley (the character played by Tom Selleck) had a Sharps with an ultra-long barrel (four inches longer than the standard thirty-inch barrel) that was extremely accurate at a long distance. In the film, Quigley amazed everyone with his ability to hit targets at tremendous distances.

It should be noted also that most of the standard-length rifles had shorter carbines that used the same ammunition, but they had a shorter range and were not as accurate. Even the very accurate Sharps had a carbine model.

Revolvers were, of course, also used extensively during the war, with the colt .44 and .36 being the most popular. The French LeMat revolver was used by Confederate officers. In addition, bayonets, lances, sabers, and swords of various types were used, but in reality they inflicted few casualties.

The other weapon that was used extensively was the cannon. Both smoothbore and rifled cannons saw action. And again, it was the rifled cannon that was most accurate. Projectiles for the cannon were designated by their weight, ranging from twelve pounds up to ninety pounds and more. As in the case of the rifle, the cannon could be breech-loaded or muzzle-loaded. The three main types of artillery were cannons, which fired shells that followed a relatively flat trajectory; mortars, which fired shells into a high, arching path; and howitzers, which were in between. One of the most popular cannons was the smoothbore called the “Napoleon.” It was used both by the Union and the Confederates. It was relatively light and portable, and it had a range of about seventeen hundred yards. It was frequently used to shoot canisters and grapeshot, both of which were deadly to an approaching army. Canisters held about eighty-five iron balls, and they disintegrated soon after being fired, spraying the balls over the landscape, causing large numbers of casualties. They were, in effect, like a giant sawed-off shotgun.

THE WAR

Neither side expected the war to last more than six months, and no one expected the ferocity and high numbers of casualties that it caused. By the end of the war over seven hundred thousand soldiers had died, along with a large number of civilians.

The American Civil War began shortly after the election of Abraham Lincoln as president in 1860. Lincoln opposed slavery, and several Southern states feared that he might try to outlaw it. As a result, in 1861 several slave states seceded from the union and formed their own government: the Confederate States of America. Washington did not recognize the secession, and Lincoln was determined to keep the states together.
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Fighting began when the Confederacy began shelling Fort Sumter, a garrison in the middle of the harbor of Charleston, South Carolina. After extensive damage, the garrison finally surrendered on April 13, 1861. Lincoln was outraged; he immediately called for volunteers for a Union Army. Soon four more states joined the Confederacy. Within a short time both sides had armies of around one hundred thousand men, but most of them were untrained.

Over the next four years, 237 battles were fought along with many minor skirmishes. And the war became increasingly ferocious as the dead piled up. One of the main reasons for the huge number of casualties was the tactics used by the generals on both sides. Napoleonic tactics had been drilled into the officers at West Point, and they were still used extensively for the majority of the war. As we saw earlier, in the Napoleonic Wars, soldiers arrayed in battle lines marched toward one another with their muskets. They usually fired when there were about a hundred yards apart; at this distance their bullets were barely able to reach the enemy, let alone hit anyone. The order was usually, “Ready…. Fire!” rather than “Ready…. Aim…. Fire!” Their goal was to create a hailstorm of bullets on the enemy, hoping that some of the bullets would inflict damage. Once their single-shot, slow-loading muskets were empty, the soldiers would run at one another with bayonets in hand-to-hand combat. The problem with this was that since Napoleon's time, rifles and cannons had become much more deadly and had a much greater range. Soldiers could now pick out targets and hit them at two hundred yards. So frontal assaults of the type described above became almost suicidal. Nevertheless, a soldier would be quickly branded a coward if he tried to take cover instead of advancing toward the enemy's guns. As a result, soldiers were “mowed down” as they moved toward the enemy. Not until later in the war did generals finally abandon this tactic.

Early in the war President Lincoln ordered a naval blockade of the South
in an attempt to stop all trade, particularly the import of weapons from Britain and France. And it was, indeed, quite effective, mainly because the Union had a much better navy than the South had. One of the major things it did was stop the export of cotton, the South's major export, which accounted for a large fraction of its economy. Early in the war the Confederates, led by General Robert E. Lee, won several critical battles. But by the summer of 1862 the Union had destroyed many of the Confederate armies in the West, and it had seriously degraded the Confederate naval forces on the Mississippi River. Then came the Battle of Gettysburg in 1863. Lee was pushing his army north in hopes of a decisive victory that would demoralize the Union. He had approximately seventy-two thousand men; opposing him was a Union force of ninety-four thousand men under the command of General George Meade.

The fighting started on July 1 on the outskirts of the small town of Gettysburg. The Union army was assaulted by Lee's army, sending them retreating to Cemetery Ridge south of the town. On the second day the two armies were again ready for battle, with the Union army laid out in a defensive formation. Late in the afternoon Lee's army charged at several points along the long defensive line and nearly succeeded in breaking through. Lee was now confident; his army had inflicted considerable damage on the Union line, and he was sure victory was at hand. On July 3, he began with an artillery barrage involving 135 cannons, many firing twelve-pound shells, and others firing deadly canisters that could spray troops with lead balls. In addition, he had twelve-pound shells packed with gunpowder that would explode over enemy troops, spraying them with fragments of iron from the shell. Lee's plan was to disable as many of the Union guns as possible, along with soldiers. He knew he would have to devastate and demoralize the Union forces before he could attack.
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Soon hundreds of rounds were being fired from the 135 Confederate cannons, and within a short time an equal number of Union cannons joined in. The roar was deafening, but even worse was the smoke from the two rows of cannons. The entire area was soon engulfed in a gray, acrid smoke that stung the soldiers' eyes. The bombardment continued for hours, and to Lee's disappointment, the Union counterbombardment didn't stop or even falter. Nevertheless, by midafternoon Lee decided to go ahead with his attack. Brigadier General Pickett was in charge of the attack; 12,500 Confederate troops lined up for what became known as Pickett's charge. The Confederate soldiers were armed with Enfields, and the Union soldiers carried Springfields. Some of the troops even had the incredibly accurate Sharps. The rifles carried by both armies used Minié balls that had ranges of at least a quarter of a mile. As the Confederates moved forward across the open field, the Union soldiers were waiting for them behind
a low stone wall. They let the Confederates move closer and closer. Finally the Union troops let loose, and at the same time Union cannons began firing canisters and exploding shells above them. Some of these shells took out two men at a time, and the Springfields were almost as deadly.

Strangely, the Confederates didn't take cover, but kept coming. The slaughter continued as they approached, and by the time they reach the Union lines, almost half of them—close to six thousand—had already been killed. A brief hand-to-hand battle occurred, but it didn't last long. Within twenty minutes the Confederates retreated, leaving the battleground strewn with bodies.

That night it poured rain, and the battlefield became a field of mud. No one was in the mood for further battle. Seeing the damage to his army, Lee finally decided to retreat. In all, each side suffered incredible casualties—the greatest of the Civil War: twenty-three thousand on the Union side, and about the same number on the Confederate side.

The war continued for another two years after the battle at Gettysburg, but the momentum was now on the side of the Union. In 1864 President Lincoln appointed General Ulysses Grant as chief of all Union forces, and the “limited” war to restore the Union became “total war” to destroy the South and slavery, and to restore the Union. The South fought on valiantly, but it suffered defeat after defeat and was finally brought to bay in April 1865.

THE ROLE OF THE TELEGRAPH

One of the more important devices that came directly from discoveries in physics and was used extensively in the Civil War was the telegraph. It was a communication system that transmitted electrical signals over wires from location to location. These signals could then be translated into a message. President Lincoln used the device extensively throughout the war to keep in touch with his generals and other officers. He was well aware of the value of the telegraph and was the first president to use it to give direct orders on how a war should be conducted.
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The roots of the new technology went back to 1823 when the English inventor William Sturgeon (1783–1850) devised the first electromagnet. Faraday had shown that when a current was passed through a coil of wire (what we now call a solenoid) a magnetic field was produced. Sturgeon began by repeating Faraday's experiments, then he went on to wind wire around an iron bar; in particular, he wound eighteen turns of bare copper wire around it and found that it produced a relatively strong magnet, so strong, in fact, that it could lift twenty
times its weight of iron. And for the current, he used only a simple single-cell battery.

News of the discovery reached Joseph Henry (1797–1878) in United States, and he decided to do the same experiment with insulated wire. Sturgeon had kept his wires well-separated from one another so they would not short-circuit. But Henry's wires were insulated, so that wasn't a problem; he therefore wound them on top of one another, and he could use hundreds of turns. By 1831 he had produced an electromagnet that could lift over a ton of iron. Then he hooked it into a circuit and showed that it could cause a lever to strike a distant bell. To see how he did this, consider a simple circuit (shown below) that includes an electromagnet. Assume there is a key in the circuit that can be pressed to complete the circuit, but when it is released it snaps back as a result of a spring to break the current so that no current flows. When the key is depressed, the electromagnet in it is actuated and can attract the nearby iron bar. Again, if this bar is part of the circuit, when it is attracted it will break the circuit. Furthermore, if a bell is placed nearby, the bar can strike it when the key is depressed.
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Now consider the case of an iron bar that is not part of the circuit. In this case, the electromagnet attracts the bar to it and keeps it there. It releases only when the key is released. So if you press and release the key, the bar will snap back and forth according to the pattern you apply to the key. If the electromagnet is at some distance from the key, a “message” of clicks could be sent from the key to the electromagnet. And what was particularly important was that it traveled at the speed that electricity travels in a wire, which is close to the speed of light.

In 1837 the British physicists William Cooke and Charles Wheatstone patented a device based on this idea, and it is generally considered to be the first electrical telegraph. But it had problems. One of the major ones was that the current in a wire decreases as the wire's length increases because of the resistance of the wire. So a message in the above device couldn't be sent very far. Cooke and Wheatstone did, in fact, invent a device that helped, but it was the American Joseph Henry who improved the device and made distant telegraphy feasible.

Henry devised what is now called the relay. He used a wire for the original current that was short enough so that the signal could still be detected, even if it was quite weak. As a result, the electromagnet could still pull a lightweight key toward it. When it did this, however, it was set up so that it closed a gap in a second circuit that was powered by a battery, and this battery produced a large current in the second circuit. It was not a very long circuit and had little resistance, so the current was stronger. And of particular importance, this secondary current created the same “message” that was flowing in the primary circuit, but it was much stronger. This technique, in fact, could be applied to many additional
circuits, so by using relays and batteries at appropriate intervals, you could send a message over a considerable distance. In 1831 Henry sent a message over a distance of a mile, and within a short time this was extended to many miles.