Japan, voluntarily cut off from the rest of the world, ignored guns completely until the 16th century. Then, for a short time, Japan had more handguns — but little artillery — than anywhere else in the world. Guns, however, let a low-born peasant who couldn’t even recognize a good sword kill any samurai master of swordsmanship. Therefore the samurai, who controlled Japan, stopped all development and most manufacturing of guns.
Europeans, on the other hand, not only adopted gunpowder, they continued to improve it. They increased the proportion of potassium nitrate to make a more powerful explosive. Then, because the three components of the mixture tended to separate, they mixed them wet and formed them into “corns,” which could not separate. Near the end of the gunpowder era, they molded the “corns”
into various sizes depending on the size and mission of the gun. Some were made with a hole through them to produce a powder than gave consistent gas pressure. As the outside of a corn burned, the surface decreased, causing pressure to drop. But as the inside of hole in the corn burned, the surface increased, producing more gas and raising the pressure. All this “burning,” of course, happened in about 1/100,000 of the blink of an eye.
Guns were not the only use of gunpowder. One use gave new life to one of the earliest techniques of siege craft.
Chapter 11
Digging Down and Blowing Up: Mines
U.S. Grant’s Union armies were closing in on Richmond, capital of the Confederacy in 1864. Robert E. Lee’s men dug an elaborate system of trenches, bunkers, and strong points north of the city, so Grant tried to attack from the south while he held the Confederates in place north of Richmond. But Lee had begun fortifying the southern approach, around Petersburg, before the Yankee move. The Confederate fortifications were immensely strong around Petersburg. At one point, the troops of General Ambrose Burnside’s Ninth Corps were only 150 yards from an enemy salient protected by a mass of trenches and dugouts on a hill top. Confederate fire from the fort was so heavy there was no way to move forward.
“We could blow that damn fort out of existence if we could run a mine shaft under it,” said a soldier of the Forty-Eighth Pennsylvania Infantry. The forty-eighth, recruited in the anthracite district of Pennsylvania, was full of coal miners. Colonel Henry Pleasants, the regimental commander, overheard the soldier’s comment. Pleasants himself was a mining engineer in civilian life. He asked the army engineers about mining the fort. Mining enemy fortifications is an ancient tactic, one that was practiced long before explosives were discovered. The pre-explosive method was to tunnel under a fort’s walls, propping them up with timber as you dug. When the mine was completed, the besieger set fire to the timber, and the wall collapsed. But when Pleasants consulted the army engineers, they said the project was impossible. The tunnel would have to be 500 feet long — too long to allow for ventilation.
Pleasants was not discouraged. He convinced his superiors, right up to General George G. Meade, commander of the Army of the Potomac, that the project was feasible. Meade convinced Grant, the commander-in-chief. Grant gave Burnside’s Ninth Corps the job of blowing up the fort and opening the way to Petersburg. Burnside was delighted. Breaching the rebel line would make up for his bloody failure in the attack on Fredericksburg in 1862. He began training his only fresh troops, the eight African American regiments of the Fourth Division. When the mine went off, he expected that it would kill most of the enemy soldiers in the fort and stupify the survivors in the nearby trenches. The assault force was to run around the crater caused by the explosion and continue straight on into Petersburg. The troops following them would widen the breach, prevent the Confederates from closing it by blocking reserves, and follow the Fourth Division into the rebel city.
Meanwhile, Pleasants’s miners were tunneling toward the Confederate fort.
They got no help from the official engineers, so they improvised their own tools and scrounged up lumber to reinforce the shaft. Pleasants, using a borrowed the odolite (an instrument for measuring vertical and usually also horizontal angles), plotted the shaft and designed a ventilation system using a fire to create a draft and suck fresh air through the 511-foot tunnel. When they reached a point they calculated was under the Confederate position, the miners dug lateral shafts and filled them with 8,000 pounds of gunpowder.
The stage was set for an explosion that would be heard around the world.
Then at almost the last minute, Meade changed the plan. He decided that Burnside’s black troops were not up to leading the assault. Instead of the black division, the assault would be spearheaded by the division led by James H. Ledlie, a general with a mediocre combat record and serious drinking problem.
Ledlie’s troops had not been trained this unusual type of assault. The black Fourth Division would be the last of Burnside’s men to enter the breach.
The mine exploded with a deafening blast. The Confederate strongpoint was replaced by a hole 170 feet long, 60 feet wide and 30 feet deep. A battery of Confederate artillery and a whole infantry regiment were either blown into the air or buried under tons of dirt. Ledlie’s untrained riflemen dashed towards the crater while their commander stayed in his headquarters swilling rum. When the Union soldiers got to the crater, they stopped and stared, dumbfounded by the destruction. Some even ran down into the hole; Climbing out of it was not easy, they found. The other divisions, equally untrained, joined Ledlie’s in mill-ing around — and inside — the crater. The black division, the only one trained to exploit the explosion, had trouble getting through the mob of white colleagues.
By that time, the Confederates had had time to gather their reserves and counterattack. The Union attack was a failure, and the Federal troops were driven back with heavy casualties.
Mining, which had been so devastating against ancient, medieval, and early modern stone forts, has not had nearly as much success against modern earthworks. It was tried again in World War I, opening the Battle of the Somme (see Chapter 27). In preparation for the attack on the German lines, British engineers had mined a German strongpoint called the Hawthorn Redoubt and placed 18 tons of high explosive under it. At 7:20 a.m., 10 minutes before the attack, they touched off the explosives. The blast practically leveled the hill and killed all the Germans manning the redoubt. It did not, however, affect the machine guns in the adjoining German positions. The infantry assault was a total failure. Few of the Tommies even reached the German lines, and the British lost 20,000 dead on that first day of the battle. Mining would have been more successful in the smoothbore era, when the range of small arms was less than 1/10 of that of rifled guns.
The origin of mines is lost in the mists of prehistory. There were two principal defenses against mines in those days. One, known to all fanciers of medieval castles, was the wet moat. At the time primitive mines were being used, there was no way to dig under a body of water while preventing the water from pouring down from the moat through the earth and filling the tunnel, if it didn’t collapse the tunnel outright.