One should not let one’s self get out of the mindset that all manufacture of Black Powder is dangerous. Some methods may be less dangerous than others, but should never be considered as safe.
—Ian von Maltitz, black powder expert
Billowing clouds of rust-colored dust spewed out from the tires of the station wagon as it pulled into the small dirt parking lot. I watched from behind a giant mound of protective soil as the wagon parked next to my blue sedan, and decided I should probably go say hello. With the weather we expected for today, the only person who could be driving was the reenactor.
As Chris Kelley raised his average-sized frame out of the low-slung car, I saw why my straightlaced US Navy coworker Al had affectionately characterized him as “eccentric.” Chris’s pale red hair moved in unkempt, autonomous whorls in response to the gusts of wind from the threatening storm, and his round glasses contained easily the thickest light-warping lenses I have ever seen. Sticking out my hand, I introduced myself. Chris greeted me with a gigantic smile and a firm, callused shake right before he wiped his hands on his old yellow T-shirt and began to unload several mysterious wooden boxes from the trunk of his car. Civil War reenactors prize authenticity above all else, and Chris’s passion for his hobby was already evident. The large wooden boxes were without modern trappings such as wheels or clever latches, and they boasted enough scars to pass for well-worn 1860s antiques.
After Dale’s directive to “buy some cast iron and shoot it” I sent out feelers into every community I knew, trying to find someone with a period-accurate rifle. My navy friend had put me in touch with Chris, an old buddy of his from their active-duty days who just happened to live near Duke. Chris took his role as a Civil War reenactor with the 42nd North Carolina very seriously. He had proudly sent me a sepia-toned picture of himself in full reenactment regalia, standing in the woods with a swollen face, happily tolerating a massive pollen-induced allergic reaction because—as he stated—Benadryl had not yet been invented in the 1860s. The picture, combined with the fact that his email handle was a reference to Mad magazine, gave me the impression of someone passionate who had long ago stopped caring what anyone else thought of him and his hobbies. I was delighted to find I was correct, and that he was willing to volunteer his time and rifle to my little project.
“So this is finally happening, huh!” he gleefully declared.
“Ha! I know, right?” I replied sarcastically, rolling my eyes. Our attempts to set up the experiment had been plagued by weather: Our first test date had been canceled by a thunderstorm, and then the backup date brought us an actual hurricane. Today was cloudy and rain was expected but not until the afternoon, so I had optimistically declared that it was finally the day to head to the firing range.
In North Carolina, it is legal to discharge a firearm pretty much anywhere as long as you are at least 600 feet from someone else’s building of residence, and people often do. In my neighborhood, some sit in their backyards in camping chairs on the weekends, drinking beer and firing .22 rifles at old pans and bottles. This is not unusual. The legitimate firing ranges in North Carolina, therefore, are designed with the assumption that people have bothered to make the trip to use only their really big guns.
The massive firing range that agreed to host our science had been carved out of the hilly, forested terrain with heavy machinery, and the displaced red Carolina clay had been piled high into towering berms that separated the numerous firing stalls. After Chris refused to let me carry any of the enticing-looking aged boxes, instead arranging them on his shoulders with an ease and grace clearly born of practice, I descended with him into the excavated pit. We walked around a crook in the path to disappear behind one of the massive clay walls, and I showed him to the stall I had claimed at the far end of the row.
My undergraduate student, Henry Warder, looked up from his squatting position as we trundled into the isolated strip of grass. Henry had been assigned to me by Dale a few weeks back, and it was part of my job as his graduate student (so I was told) to help mold Henry’s young scientific mind. I had liked the tall, lanky Henry immediately because he was unique among undergrads in his willingness to ask questions. He understood that I was sleep-deprived and wanted efficient honesty, not polite reverence, and he told me right away when what I had just requested made no sense to him instead of hiding from me for two weeks before admitting he had been confused.
Henry was scrounging in the dirt and grass, making tiny piles of pebbles. The clouds had begun to release sparse droplets of rain, and he wanted to prop as many of the electrical junctions off the ground as possible. The cables stretched the length of the entire pit, connecting a remote trigger to the high-speed video camera positioned just next to our targets. This way, we could stand at a safe distance while controlling the recording. Henry and I had soldered together a custom electrical harness to connect the camera to two boat batteries as an improvised yet effective remote power source, and the entire setup was protected by thick plastic sheets propped up to guard against ricochets. We would stand and wait in the rain, because the expensive camera and its batteries had first rights to the lab’s only portable rain shelter. As Henry unfolded from his squat to come say hello, Chris thunked the boxes down on the covered picnic table in the corner of the pit and began to open them.
The men on board the Housatonic reported firing at the oncoming Hunley in the moments before the attack. The lucky-shot theory stated that one of these bullets sank the sub by damaging the fore conning tower and allowing the boat to flood. Of the firearms the crew used, the most powerful would have been their standard-issue Springfield rifles; however, the vintage firearms from that period are no longer considered safe to fire because of material changes that occur to metal bodies over time. Chris Kelley “fought” for the South and therefore had a replica Enfield rifle instead, but like an authentic Springfield, it fired the same malleable, lead, hollow-ended Minié bullets of the time period. And more important, like a Springfield it had a muzzle velocity of about 300 meters per second.
A target does not know the political allegiance of the gun that fired at it, or its date of manufacture. All it knows is the kind of bullet and the velocity of the bullet at the moment of impact. For the purposes of this test, therefore, Chris’s replica Confederate gun would convincingly pretend to be an authentic Union weapon.
As the sparse but fat rain droplets began to plunk down around us, Chris brought out his tins of black powder. He poured a small dose of the tiny black granules into the muzzle of the gun, added a bullet, and gently tamped it down before taking aim at the first cast-iron target. The sharp crack of the rifle reverberated between the walls of the deep pit, and an immediate white cloud of smoke consumed Chris as the sulfurous smell of fire and rotten eggs filled the air. As Chris shot at each of the numerous cast-iron targets, it became clear why he had chosen a grungy T-shirt to wear for the test day: With each firing, another thin coat of pungent smoky residue added to the layered accumulation of black powder crud that soon enveloped his entire body.
He licked his lips to clear them of some of their caked black coating, looking down at the ground and softly muttering profanity after a missed shot. Returning to the picnic table to reload, he licked his sooty fingers and used them to help wipe some of the obfuscating accretion from his thick glasses.
“Stuff gets everywhere,” he said. The smoke from the powder had painted Chris like a cartoon caricature of a chimney sweep.
The lucky-shot testing took two days, nestled in the deep orange-red pit of the firing range. Drenched and chased away by the rain halfway through the first day, Henry and I returned to the lab to regroup and to find more cast-iron samples with a wider range of thicknesses. By the end of the second day we had not only accumulated a small crowd of curious North Carolinian gun enthusiasts, but the results of the testing were clear: The thinner samples had shattered, splintering apart in radial patterns that propagated all the way to their edges, fracturing them into a million razor shards. The thicker samples had been penetrated cleanly by the bullets, with plastic deformation and tearing around the edges of the small holes as the bullet pushed the iron wall backward before breaking through. These two patterns were how the material of cast iron failed in response to bullets. In the process of this discovery we had also shot to death one wooden stool and irreparably warped two metal ratchet straps.
Neither of the two patterns of failure matched the clean-edged, medium-sized chunk that was missing from one section of the un-shattered conning tower. While it was possible that rifle fire had smashed the glass of the small, forward-looking navigational window or damaged one of the metal rings holding that glass window to the conning tower, the grapefruit-sized chunk neatly excised from the body of the otherwise intact tower more than likely hadn’t been taken out by a bullet.
Back in my narrow office and sheltered from the rainstorms, Henry and I spent weeks scribbling equations on the whiteboard and programming them into a computational script. Our goal was to determine how the physics that dictated the sinking behavior of the boat compared to the narrative of the lucky-shot theory. The failure patterns of the cast iron didn’t fit the theory, but as scientists we still needed more data to declare it debunked.
The theory stated that the boat started sinking immediately after the attack on the Housatonic. In our system of equations, the downward force of gravity fought against the upward force of buoyancy to see which could tug the Hunley harder. The force of water pushing inward railed against the resistance of the gas pressure building up inside as the internal air was compressed. Our code calculated the rate at which water would fill the submarine through various-sized holes in the conning tower, from as small as the bullet holes in our samples to as large as the chunk actually missing from the recovered Hunley. For each size of hole, we calculated a length of time the boat would take to sink.
When the submarine was found, she was discovered with her bow pointing back toward the Housatonic, oriented exactly as if she simply drifted out to sea on the outgoing tidal current. The next obvious question, then, was how long it would take her to reach that position. Henry and I looked at the tides that would have slowly pushed the submarine seaward after her attack, and we badgered patient, helpful professors from the Duke ocean sciences department with our innumerable questions.
Charleston Harbor is one of the sites known as a “harmonic station,” which means the harbor’s tides follow a simple, repeatable pattern and can be calculated accurately for any date in history. The patterns of the tides in Charleston Harbor that night in 1864 almost exactly matched the tides from February 21, 2013, a modern date with recorded data taken from a buoy stationed near the Housatonic wreck site, data that told us the speeds of the tidal currents, in the area. Based on the changes to Charleston Harbor over the centuries, such as dredging open the entrance, all of which would have increased the outflow of water from the harbor mouth, the speeds of the currents that were recorded in 2013 were more than likely the upper limit of the speeds the doomed Hunley could have experienced.
At the end of the analysis, we had a whiteboard full of equations, a stack of printed ocean-science references about Charleston, and a few key numbers. For the Hunley to reach her final location 310 meters seaward of the wreck of the Housatonic, she would have had to drift outward on the 2013-speed tidal currents for roughly fourteen minutes. Therefore, if she was floating along in the slower currents of 1864, she had to drift for at least fourteen minutes or longer to reach her final resting place. From the analysis of the fill rates we calculated that if she were filling through a grapefruit-sized hole like the one in the conning tower, she would have hit the silty bottom in at most five minutes. This five-minute time period was not enough time for her to reach her final resting place. If the damage to the tower caused the boat to sink, and the damage had been done by a lucky shot, then the Hunley would have settled to the ocean floor much closer to the wreck site of the Housatonic.
The Hunley’s crew did not set their bilge pumps to pump out water from inside their vessel, and the crew would not have sat, relaxed, and curiously watched the slow trickle of intruding water as it drowned them. The submarine was found much farther from the Housatonic than she would have been if she had swamped immediately. Therefore, she must have stayed afloat to drift for some distance after she was shot at by the Housatonic’s crew.
The lucky-shot theory went the way of the theory of suffocation as Henry and I crossed it off our mental list of possibilities. Three months after the publication of the academic paper describing our scientific results, which was our second paper on the topic of the Hunley, the collaborative group including the Friends of the Hunley stated in an informal web article that they thought the submarine would have needed to drift for about thirteen minutes to reach her final resting site, further supporting our conclusions.
Chris, Henry, and I had begrudgingly dealt with black powder to make our gunshots as period-accurate as possible, but in the 1860s the messy substance was the unavoidable lifeblood of both the Union and Confederate militaries. Without it, the most effective wheels of warfare would grind to an immediate halt: No guns could be shot, no cannons could be fired. Nothing would have been possible but bayonets and swords and fistfights in the mud. Black powder isn’t a powder in the fluffy, soft sense of flour or snow; it’s a coarse, pearlescent sand with large granules. The polished grains have an unmistakable smell, and everywhere they travel they leave behind a trail of telltale soot like so many minuscule black chemical snails.
Chris had repeatedly packed small doses of the powder into the muzzle of his rifle for shot after shot, and each time some of the grains had escaped and pinged off the picnic table, rolling away along the edges of the wood. I would press the tip of my index finger down on them, sticking the dots to my damp skin so that I could stare at their little spherical shapes. Individually, these granules were harmless. Light a match to one single grain of rifle powder and it will simply vanish, almost unnoticeable in its reaction. But assemble enough grains to fill the muzzle of a rifle, and their cumulative heat and gas can fire a bullet with lethal speeds. Compile an army of grains, enough to fill a beer keg, and you can destroy a ship. They’re like ants: harmless alone, powerful in numbers.
The modern granules rolling down the table were the refined product of thousands of years of bloody evolution. Originally invented by alchemists in China around the year 220 BCE, black powder expanded to ubiquity once its utility as an explosive became apparent. Since then, each generation of warfighter has tried to improve upon the substance, sometimes succeeding in enhancing the power of the product, but more often blowing themselves to pieces. By the time of the Civil War, the dangerous process for making black powder had been refined to only three deceptively simple ingredients: sulfur, potassium nitrate, and charcoal.*
The sulfur, a soft, dusty, pale-yellow element with the chemical code name S, usually forms a mere 10 percent of the final powder by weight. However, even in such a small percentage the sulfur was the reason that the burnt powder caking Chris Kelley’s face had the overwhelming smell of rotten eggs. When the sulfur burns it forms hydrogen sulfide, and the odor comparison is not a metaphor; the exact same chemical is produced as eggs begin to decompose. Hydrogen sulfide also spews from the mouths of volcanoes alongside the ash and lava, earning sulfur a place of honor in the Bible’s description of hell under its other, much more famous, name: brimstone.
The simplest way to make black powder starts with mixing pulverized yellow sulfur together with the powder produced from ground charcoal. The black and the yellow swirl together in the mixing bowl beautifully, creating tiger stripes before blending to a homogenous, dark dust. The charcoal, only 15 percent of the final black powder by weight, is how the explosive product receives its signature color.
The magic ingredient contributed by charcoal is its carbon, a fundamental element denoted simply by the capital letter C. Carbon-to-carbon bonds are the I-beams that, when assembled neatly, construct a diamond, when laid flat into tidy sheets make graphite, and when jumbled into a degree of chaos become charcoal. Chemist Walter White said in the television show Breaking Bad, “Carbon is at the center of it all,” meaning all of life and most of chemistry, and his words are absolutely true for the chemistry of black powder. Together the sulfur and the carbon are building blocks, eagerly waiting to be rearranged into lower-energy states, releasing their inherent energy as heat, light, and sound in the process.
The charcoal for black powder can and has been made out of pretty much any wood in the world. The type of wood will lead to some variation in powder performance, but what is truly crucial is the actual process of making that wood into charcoal. The wood must be carbonized, which means heating it to a specific, extremely hot temperature, then quickly depriving it of oxygen to stifle the burning reaction. All the water is burned off, the other miscellaneous components are burned off, and what is left is a pile of smoldering coals. These coals are scorching-hot little nuggets of desiccated tree. They have been reduced down to the carbon-carbon bonds that provide the wood’s structural essence.
The dark, dusty concoction in the mixing bowl, still just a blend of yellow sulfur and black charcoal, is not yet an explosive because it is missing an oxidizer. The main difference between an explosion and an everyday, normal fire is the rate at which the material burns. In a normal fire the materials burn slowly, and in an explosion, the materials burn at warp speed. Explosive materials can burn so quickly because they include their own oxidizer.
Any fire or explosion requires the same three elements, each a leg of the so-called fire triangle: fuel, oxidizer, and heat to start the reaction. The carbon and sulfur are fuel alone, with no oxidizer or heat yet, so the mixture in the bowl is like a pile of wood stacked beside a pit: full of potential energy, but not yet ready to be a fire. The oxidizer delivers oxygen rapidly and forcefully into the chemical reaction that is breaking down the fuel. For a normal fire fit for roasting marshmallows, air with its 0.21 atmospheres of oxygen is sufficient. The air can waft in and out through the properly arranged logs of a well-constructed bonfire, combining with the heat of the flames and the fuel of the unspent wood to keep the reaction going. However, air alone is insufficient to enable an explosion. The most common oxidizer used to make black powder is a nondescript, innocent-looking white chemical called potassium nitrate, disturbingly purchasable as a fertilizer from any local grocery store for $5.95 per half pound.
The potassium nitrate, also known as saltpeter, commonly comprises about 75 percent of the final product by weight, a large fraction that emphasizes the extreme importance of oxidation when making an explosion. It is shocking how many seemingly inert everyday materials, like titanium or most rubbers, become eager to explode when force-fed enough oxygen.
After the addition of the oxidizer, the crude black powder in the mixing bowl is, at least in theory, complete. It is a mixture of fuel and oxygen in solid granulated form, missing only heat to create an inferno. In the words of a popular blast textbook, for all types of explosives, “all methods of initiation are basically thermal in nature,” meaning whether the explosion is black powder, TNT, or C4, whether it is started with a match, a detonator, a sharp impact, or a tiny arc of unintended static electricity, it all starts with some kind of heat. For most modern high explosives, the heat must also be coupled with hydrodynamic effects, the additional forces caused by moving materials inside the charge, to achieve detonation. This requirement is why modern high explosives are far more stable than black powder. For example, the explosive C4 was designed stably so that a brick of it will not explode unintentionally even if it gets shot. But like a stack of dry leaves soaked in lighter fluid, ultrasensitive black powder “only takes one little spark to set it off.”
This instability is why the next step in the process is so discomfiting: The powder gets ground aggressively. Crushed in a pit beneath massive, beastly rolling metal wheels, the impact-sensitive explosive sand gets milled for hours. Even when doused in water to make the process slightly less dangerous, the powder is still itching for the opportunity to convert itself into a lower-energy state, which would blow the mill wheels, the mill operators, and often the walls of the entire mill building to pieces. The grinding brings the fuel and the oxidizer into even closer, more intimate contact, as the eager molecules are further intermixed and smashed into tighter proximity by the friction of the spinning metal wheels.
The last remaining American manufacturer of black powder is GOEX, located deep in the heart of Louisiana. Large, deep, water-filled containers that look similar to bathtubs punctuate the GOEX campus. These tubs are protective refuges for the employees in case of a milling accident . . . if the employees can get to one in time.
The wet milled powder is then set out to dry, and it forms into chalky cakes. The cakes are broken into particles of the desired size, and the volatile, jagged little crystals of explosive are thrown into a tumbler, where they are bounced and spun until they take the final form of the tiny, rolling black spheres that I pressed from the surface of the picnic table into the skin of my finger.
These spheres are designed to burn. Every step in the process is designed to optimize the eagerness of these little spheres to burn as rapidly as possible to create the fastest explosion possible, and every step that occurs after the addition of the potassium nitrate carries a risk of an unintended blast.
During the Civil War, a common test for the quality of black powder was to create a small pile of grains in the palm of your hand, then light it on fire. If the pile disappeared in a flash, leaving your hand unharmed, then the powder burned quickly enough to be considered good quality. If it lingered, scorching your flesh, then the burn was too slow to be useful.
The explosion of black powder, although engineered to be as rapid as possible, is still not fast enough to be called a detonation; instead, the explosion of black powder is called a deflagration. The term “detonation” is reserved for explosive materials that have achieved an important accomplishment in the world of fire: The flaming front of the chemical reaction burns through them faster than the speed of sound. A deflagration is slower than the speed of sound, a plodding, deliberate movement of the burn as it jumps from granule to granule. Both are proper explosions, both can be lethal, but the physics in each case is different. Unlike a detonation, the blast pressure produced by a deflagration also varies based on the type and strength of the casing that contains the explosive material.
In a black powder explosion, first something causes an ignition, whether it is a mercury fulminate cap like in the Hunley’s torpedo, an arc of static electricity, a sharp impact, or one of a hundred possible alternatives. Regardless of what it is, something transfers sufficient heat to the first granule at the ignition site for it to catch fire. This tiny black ball then spews heated gas and particles outward as it burns, and the gas and particles smash into the neighboring granules. The neighbors catch, their polished spherical surfaces burning first before the reaction moves internally, and they too spit out gases and particles and more heat to even more neighbors. The burn front moves forward in this way, consuming sphere after sphere as it rages outward from the initial point of ignition. The gas pressure builds and the heat grows with each grain consumed.
Eventually, as the internal pressure grows, the casing containing the powder reaches its failure point. If the powder is spread out on the ground it simply burns, with little damage and no explosion. Because there are no walls to confine the gases, they release into the air, and the reaction occurs relatively uneventfully. If the powder is lightly confined by a weak container, the walls rupture easily at a low pressure, and the gases of the explosion are therefore released at that low pressure. Hollywood takes advantage of this feature by filming explosions made by black powder that is confined by weak paper tubes. The tubes rupture easily and therefore release lower, less-dangerous levels of pressure than an explosive like C4 would, but still create visually impressive smoky blasts.
If the powder is strongly confined instead, for example in a sturdy casing of steel or copper like the torpedo on the little submarine’s spar, the gases build until they reach pressures strong enough to destroy the thick casing material. As the powder burns the pressures rise, growing until the casing, unable to control the fury, begins to melt and shred from the inside. The pressure is released as a pop, a sudden, massive, cathartic bursting, an overinflated balloon finally yielding but on an awesome and fatal scale. The casing becomes shrapnel flying outward, and the gases and by-products of the burn become the characteristic plume of smoke and destruction that is the signature image of an explosion.
Common, everyday pressure cookers are designed to cook food quickly by strongly containing unusually high levels of pressure. For this reason, pressure cookers filled with deflagrating explosives have become a popular bomb design with terrorist groups such as al-Qaeda. This bomb design was used in the Boston Marathon bombing on April 15, 2013.
By the time we had finished testing at the firing range, I was on a full-tilt mission scavenging for historical blast-test data using black powder, and I had dragged Nick into the quicksand with me. He had not been chased off by the visit to the Hunley museum in Charleston and the time with my parents, and he now sat in a desk chair across from me. We were both scooted up to opposite sides of a long table in the austere National Archives reading room in Washington, DC, and archivists clad in light-blue collared jackets roamed silently among the fervent researchers. The high ceilings sent every noise pinging back and forth across the room in a million echoes between the towering shelves of books, so the other hopeful patrons and I were all doing our best to search quietly through the yellowed pages of the priceless historical documents we held on our desks. I was leafing slowly, delicately, through fragile handwritten papers with their detailed descriptions of Civil War gunfire tests. I glanced up at Nick, and he quickly redirected his gaze to pretend that he hadn’t been staring at the top of my head, psychically trying to persuade me to declare we were finished for the day.
Nick was a firefighter and had multiday breaks as a normal part of his work schedule. He had donated one of these breaks to travel to DC with me and add his eyes to my search. The National Archives contain a bottomless supply of history that is limited only by the number of hours of life a researcher can dedicate to staring at old-fashioned handwriting. We had been rooted to these seats for days, trying to find information on Confederate black powder and, while we had found many other invaluable Hunley-related historical nuggets, as far as useful data about black powder testing, we had mostly come up empty.
The performance of black powder can be erratic and inconsistent even with tightly controlled modern manufacturing methods. Its behavior often varies substantially between seemingly identical lots whose only difference was that they were manufactured on separate days. I wanted at minimum to get an idea of the manufacturing processes that would have been used to fill the Hunley’s torpedo so that I could estimate how much the performance of the Confederate powder might differ from that of modern powder. I didn’t have any extra years or limbs to sacrifice to copying their process and making my own replica powder, so instead I had decided to turn to the archives for data.
The faint siren of a distant fire truck disrupted the silence of the reading room, and its cry grew to a wail as it passed beneath the windows of the National Archives Building. Nick’s spine stiffened in response to the call of his profession. He jumped from his chair and bolted to the window to smash his hands and face against the glass like a deranged car-window Garfield toy, his whole demeanor screaming that he wanted to be part of the emergency instead of reading more documents. My bellows of exhaustion-exaggerated laughter rang out through the long room, and tears streamed down my face from the much-needed release. After finally recovering my breath I was forced to admit to myself that we were both at our limit of cognitive usefulness, that the Confederacy’s black powder secrets had been preserved elsewhere, and that it was time to go home.
I was hopeful I had arrived “elsewhere” as I pulled in to the Hagley Museum. The drive from North Carolina to Delaware had been long, and the sun had already gone down on the closed museum property. Mine was the only car in the small parking lot at the remote back entrance, and a thick downpour gushed over my windshield. Crouching under my little red umbrella, I ran toward the hewn stone edifice of the darkened building I guessed was the former blacksmith shop, where I was supposed to stay for the week. After punching the key code on the locked door of the unoccupied shop, I was relieved when it creaked open to allow me in out of the deluge.
The Hagley Museum is not a normal museum. It is a former black powder mill, built by French immigrant Éleuthère Irénée du Pont in 1802. The famously wealthy du Pont name is now firmly associated with a diverse portfolio of chemistry and innovation, but E. I. du Pont first established the base of the family fortune by grinding black powder at this mill. As all the other American powder manufacturers shut down, one factory at a time, each sent their black powder documents for preservation to the du Pont–funded library and archives at Hagley. The working steel rollers of the museum’s mills still turn inside their massive stone hutches, powered by the endlessly churning waters of the Brandywine River, but now they grind away at nothing and serve only to delight visitors.
“They have everything ever written about black powder,” the woman in charge of research at GOEX had told me when I had called her begging for data. “Everything.” And after a $400 travel grant provided by the good folks at Hagley, I had finally arrived to bury myself in their historical treasure.
The archives at Hagley are stashed in a building called the Soda House. Tucked away on the back of the mill property, the gorgeous stone Soda House and its arched high ceilings used to guard staggering white mountains of sodium nitrate. Also called nitrate of soda, hence the building’s name, sodium nitrate is an oxidizer that replaces potassium nitrate in the specialized black powder destined to blast open mines. These days the statuesque building serves as a wedding venue, and the high arches are home to black powder documents instead of ingredients. They contain shelf upon shelf filled with the same gray filing boxes found in every archive in the world, all tended by an ingenious man named Lucas Clawson.
Lucas knows the archives of Hagley; he knows them as if he had been born in the aisles between the stacks. I sat at one of the long tables in the massive, vaulted, white-walled reading room with my camera, tabletop tripod, and document stand ready for action. I was instinctively quiet even though I was the only one there. Lucas would silently appear carrying filing box after filing box, placing them on the table for me to photograph before he once again disappeared without a word back out the door to the stacks. Between his meticulously groomed handlebar mustache and his deliberately antique fashion style, I felt as if I were being handed the secrets of the Hunley’s torpedo by my own personal Civil War ghost librarian.
It was through Lucas Clawson that I first met George Washington Rains, military chemist and Confederate black powder demigod.
George Washington Rains was a man of intensity. Given the unlimited options provided by a long weekend, he once declared that the best possible use of the time was for his friends to join him on a 90-plus-mile hike from Fort Monroe, Virginia, to Richmond. He then insistently set for them a furious and unyielding pace of 30 miles a day at 17 minutes per mile. The determined young chemistry professor, carrying a sack full of food and wearing his military cap with a pair of torn, ill-fitting trousers, mustered the group at four o’clock in the morning and never once paused in his relentless tempo. After three long days, drenched to the bone from a torrential downpour, Rains led the march into town, sodden, victoriously on schedule, and in search of more whiskey to refill yet again the flasks the men had already emptied many times on the road in toasts to fallen soldiers.
Born in 1817 in New Bern, North Carolina, Rains came from a family of genetic intensity. After excelling his way through school, he graduated and left to join his older brother Gabriel in “Indian Territory,” described as “a primitive wilderness inhabited only by savages.” Successful brother Gabriel received promotion after promotion in the US Army, one of which was a reward for the invention of one of warfare’s most notorious innovations: the land mine. He would construct sensitive black powder charges and hide them, leaving them for a Native American warrior to step in the wrong spot and trigger the explosion.
Whatever George Rains saw during his time shadowing Gabriel clearly convinced him of two things: First, he needed to join the army, and second, his job also needed to involve explosions. After the year with his older brother, the younger Rains returned to enroll in West Point with the goal of studying chemistry.
George Rains’s career with the US Army then became a relentless search for ever-greater excitement. He was originally appointed to the Engineer Corps, but a politely phrased obituary would later state that “the quiet and monotony of the Engineer Corps became irksome to him,” and he promptly requested a demotion to allow him to access the fireworks that he assumed would come with a job discharging heavy artillery. His request was granted, and he was knocked down the pay scale. At first, the 4th Artillery seemed to have everything he had wanted, but again it was soon revealed to provide insufficient adrenaline. Rains became known for writing letters and pamphlets arguing that even in peace the artillerists should be given more shells to use for far more frequent practice. By 1844, a year of relative peace for America, the bored and disenchanted twenty-seven-year-old Rains was willing to accept a placid appointment back at West Point as a professor of chemistry, geology, and mineralogy. However, at the outbreak of the Mexican War in 1846, he immediately clamored to be sent into combat.
There was only one person to whom George Washington Rains wanted to write to express his excitement over his love of battle: his older brother, Gabriel. In one particular letter full of lengthy and delighted exclamations about battles and troop movements, the only hint that the two men shared anything besides warfare is shoved in as a final sentence, jammed awkwardly beneath the printed lines on the stationery as a token and seemingly obligatory admission that something exists besides battle: “Give my love to Mary & Stella & Lauren, Affectionately, Your Brother, George Rains.”
With the unexpected outbreak of war in 1861, both militaries found themselves short on powder. The Confederacy had stockpiled at most a few months’ supply, and the secessionist states did not contain a single modern industrial mill capable of supplying the military with more. Almost 1.2 million kegs of black powder were made in America in the year 1860, but less than 0.9 percent of those were manufactured in what would become the Confederate States. Of the 747 total American employees trained in the art of black powder manufacture, 13 lived in the South. By the time of the war, not one former powder-making employee was available. But despite the “appalling” situation, Confederate president Jefferson Davis knew immediately where to turn: George and Gabriel Rains.
By the time of the request, the North Carolinian Rains brothers had already left the US Army to voice allegiance to their home state as true “Sons of the South.” They had the chemical, strategic, and creative acumen to supply the entire Confederate nation with black powder and munitions. And they did it so abundantly that by the war’s end they would earn a menacing nickname: “the Bomb Brothers.”
George Washington Rains had never made black powder before, and he had never even seen it being made. But the relentlessly high-octane man was armed with a pamphlet, a degree in chemistry, and a “carte blanche” from Jefferson Davis to do absolutely whatever he needed to do to supply the Confederacy. Bolting to begin his mission even before he received his official commission in the Confederate military, Rains spent the next several months endlessly traveling the Southern states, sleeping in railway cars to save time while on his quest. He needed to find the perfect site to build a black powder mill, and then he needed to gather the personnel and equipment required to do so.
His treasured pamphlet, the only resource he had for knowledge on how to build the mill, was an old publication by the Waltham Abbey Gunpowder Works in England. It described in forty-two short pages—with zero photographs, drawings, or diagrams—how black powder was made. Eventually Rains tracked down a former employee of Waltham Abbey named Frederick Wright, and the two claimed a strategic, militarily defensible spot near the railway lines and waterpower of a canal running through Augusta, Georgia. Together, they began to build. Within seven months they had erected a factory capable of supplying the entire Confederacy with all the powder it could ever need.
Rains designed his factory to explode, using a plan very similar to the mill buildings where I clambered over shattered stones at Hagley. The task of grinding the powder was subdivided between multiple separate buildings in an attempt to minimize the batch size, and therefore reduce the size of each accidental explosion. Each mill building with its massive 5-ton roller wheels had three sturdy walls, each at least 4 feet thick. The fourth wall and the ceiling were deliberately made of flimsy material, “so that but slight resistance would be offered, upwards and outwards, to the explosive force.” The hope was that, when the mills did inevitably explode, the flimsy fourth wall and ceiling would allow the force of the blast to be directed outward and away from the rest of the complex.
The mills at Hagley saw 288 explosions during their 119 years of production. Rains proudly boasted that his mills only ever saw 3. One of these incidents was thought to have occurred because a careless worker dropped a match on a floor dusted with scattered black powder, but the cause cannot be stated conclusively because no witnesses survived. The chain reaction ignited an estimated 3 tons of powder, which “vibrated the air for a mile around.” Eight were killed inside the mill building, with only small pieces of their bodies found, but a sentinel outside fell where he stood, externally intact. Rains said that “the sentinel was killed by the shock, but his body was not otherwise disturbed.”
After long months of deciphering Rains’s tightly curled handwriting with its looped h tops, I was finally able to conclude that the black powder used by the Confederacy would more than likely not have suffered in its performance because of Rains’s need to create the powder works from scratch. Rains had optimized the milling process, utilizing his full engineering and chemistry backgrounds to employ the same ideal procedures that have still not been further improved by today’s black powder manufacturers.
The chemical components of the powder, however, can also have an effect on performance, in addition to the influence of the manufacturing procedures. To evaluate the performance of the powder, I would also need to assess the quality of the ingredients Rains had used. But as I learned, he had optimized his ingredients too.
The charcoal made by Rains was manufactured from cottonwood and willow trees, using the well-established procedures prescribed by Waltham Abbey. All published texts on black powder manufacture speak highly of willow charcoal, and experimental data confirm that this charcoal type optimizes performance and burn. Rains said confidently that his own experiments showed that cottonwood worked just as well as willow, and the modern data support his statements. Again, in his selection of charcoal and in his means of making it, Rains had maximized the performance of his powder.
Finding supplies of sulfur was a nonissue, as it could be obtained easily and in a pure form through natural sources. However, potassium nitrate was a constant concern. The incredibly valuable saltpeter formed three-quarters of the final product and was therefore in high demand by the militaries on both sides. Even with an efficient new mill, lack of saltpeter would mean lack of powder, and lack of powder meant losing the war.
Rains’s first move was to rally the support of the populace. Potassium nitrate, also the critical ingredient in fertilizer, is a normal by-product of decomposition. It oozes into the soil as organic materials such as leaves and fecal matter decay, but it can be washed back out by rain. However, the soil in covered places like caves, stables, and cellars are not only subjected to a constant onslaught of animal feces released by creatures taking shelter, but they are also protected from the cleansing effects of raindrops. The soil inside these shelters can be mined and processed to yield pure, snow-white potassium nitrate, suitable for both vegetable gardens and bombs.
Rains, the former professor of chemistry-combo-geology, issued detailed pamphlets on how to process this sheltered soil, valiantly declaring to the citizens of the South that “the individual who makes a pound of saltpeter each day contributes in fact more to the ultimate success of his country than if he shouldered his musket and marched with all his sons to the tented field.” Hundreds grabbed shovels and marched into local caves, digging up dirt to supply their military with the much-needed oxidizer.
In addition to the saltpeter supplied by the people, Rains also heavily utilized blockade-runners bringing potassium nitrate from Europe. As the Union Army closed in, taking control of one cave-containing territory after another, the blockade-runners who managed to sneak past vessels like the USS Housatonic became an increasingly critical source of the precious saltpeter.
Even though Rains managed to create an admirable supply using digging and blockade-runners, the long-term plan for potassium nitrate relied on neither the people nor the passage of ships. Instead, the agriculturally minded South would farm its own. George Rains established potassium-nitrate farms, which were extensive systems of 2-foot-deep trenches. The nitrate farmers filled the trenches with decaying matter such as leaves, feces, and the rotting carcasses of stray dogs. They also periodically wet them down with more organic liquids . . . most likely urine. Eventually, the decay of the biological materials would yield an embarrassment of soil so profoundly rich in potassium nitrate that it could have supplied the Confederacy with all of the saltpeter it would ever need. However, the trenches would have taken at least eighteen months to fully “ripen,” and the war ended before their fruits were truly ready.
Rains left abundant records of his refinement process, which clearly took advantage of his extensive chemical knowledge to create the purest, most powerful potassium nitrate possible. His powder benefited from advanced manufacturing techniques, the optimum choice of wood for charcoal, and exhaustive attention to detail in the refinement of each ingredient. The performance should have been unparalleled in its time, and equal to any modern powder I might use in my testing.
A farmer somewhere in the South dug up several cubic feet of soil from inside a cave on his land. He processed it according to the pamphlet he had read, boiling and mixing it until a fine white powder condensed out. He packaged up the final product, selling it to the military for 35 cents per pound and shipping it off to Augusta, Georgia. It was added to a pile of identical white powder freshly brought by blockade-runners, who had risked their lives dodging the artillery of Union ships to deliver their packages. The saltpeter was ground and refined again, reaching a near-perfect level of chemical purity.
Somewhere else in the Confederate States, a cottonwood tree was chopped down and hacked into nuggets. The nuggets were brought to Augusta, where they were heated to the ideal temperature before being deprived of oxygen and cooled into condensed pods of carbon. The pods of carbon were ground into a messy black dust, which was then mixed with yellow sulfur.
The black mixture was gently stirred together with the white saltpeter, then poured into the metal bin of the massive mill contraption inside one of a long series of identical stone buildings. The mill operator ran to take shelter outside the building before starting the rollers, exhaling a sigh of relief as the wheels uneventfully began to churn and grind the mixture into a uniform, even blend. The black-colored powder, now an explosive, was dried, caked, granulated, and polished until it formed beautiful, even, nearly identical tiny spheres.
George Washington Rains ordered the spheres shipped to Charleston, South Carolina. The recent battle of the ironclads off those shores had consumed almost 22,000 pounds of powder, depleting the stores of the entire city and ensuring that the massive machines built by Rains would need to provide General Beauregard and his warfighters with an entirely fresh supply.
George’s brother, Gabriel, waiting for the shipment in Charleston, used much of the powder to assemble torpedoes. Gabriel had been sent to Charleston to riddle its harbor and waterways with hidden deadly torpedoes, underwater versions of his land-mine invention, and to create a lethal maze to deter the Union ships from encroaching any closer. Gabriel used his brother’s powder to fill even more of these torpedoes, sinking them in the waters of Charleston until they were “as abundant as blueberries.”
A massive quantity of the powder was reserved for a special torpedo. This torpedo was built with thick, robust metal walls to maximize its confinement, and therefore its destructive power. The deadly black sand was poured into the copper casing, and the cap with its fuse was sealed tightly in place. Then, the torpedo was bolted onto the spar on the bow of a submarine.