Storm Kings

by Lee Sandlin

  In the evenings they gathered in taverns and hotel lobbies and dining rooms, and they drank and they argued over what they’d seen. They were all evolving their own theories as to what the tornado had been and whether the evidence in the wrecked town proved them right. But one debater stood out—the most impassioned, the most eager to convince, the most certain he was right. To no one’s surprise, this was one of the visitors from the Franklin Institute, James Espy.

  James Espy wasn’t a professor but a former schoolmaster and a passionate amateur meteorologist. It was the goal of his life, in fact, to become America’s first professional meteorologist—a job that did not then exist. He was attempting to invent it any way he could, principally by lecturing on meteorology at the Franklin Institute and writing reviews for the leading journals on natural philosophy. He was fifty years old at the time of his visit to New Brunswick; he was known among his colleagues for his boundless enthusiasm for his subject and the remarkable originality of his thinking. As it happened, he believed he had discovered a new and fundamental theory of meteorology, and he had come to New Brunswick to look for evidence to support it.

  Espy had stumbled across this theory while reading a book called Meteorological Observations and Essays by a British natural philosopher named John Dalton. In one passage Dalton considered one of the puzzles that had recently arisen in the study of the atmosphere. It had been known since Franklin’s time that the atmosphere wasn’t one uniform substance but a kind of soup where several distinct elements were blended. Chemists had managed to isolate them: air was made up of nitrogen, oxygen, and hydrogen in fixed proportions. But there was something else—a small quantity of water vapor, in a proportion that seemed to be different each time it was measured. Its presence was clearly significant and necessary (people did understand that clouds and rain were formed out of water vapor), but where did it come from and why did its proportion keep changing?

  Dalton suggested an answer. The molecules of water vapor were circulating freely, suspended among the other elements in the atmosphere, and their quantity varied at any particular time according to the temperature and air pressure. The hotter the temperature and the higher the pressure, the larger the number of water molecules the atmosphere could support. The lower the temperature and pressure, the more likely it was that the water molecules would lose their buoyancy and descend back to earth.

  Dalton imagined the process mathematically. There were three numbers that could be used to quantify any body of air. One was temperature; the second was barometric pressure; the third was a new one Dalton invented. He called it the dew point. It defined the amount of water vapor the air could hold. The dew point was continually floating and shifting in relation to the other two numbers. If the temperature and pressure of a body of air declined, the air would eventually reach its dew point. The water vapor would then condense out. Close to the ground, the vapor would appear as dew or frost; in the upper air, it would fall as rain or snow or hail.

  The dew point was what gave James Espy his inspiration. He was led to it because he was fascinated by a problem about clouds that nobody had solved yet: how the various types of clouds were formed. In particular, he wanted to explain the origin and dynamics of the most extreme and dramatic cloud, the cumulonimbus, the thunderstorm cloud.

  The way most students of meteorology pictured it, the atmosphere was made up of diffuse domains of air, circulating and mingling randomly, and it was their haphazard collisions that produced clouds and rain. But Espy had a different idea. He pictured humid air near the surface of the earth being warmed by the sun and beginning to rise. Only in his version, it didn’t ascend in a shapeless, dissolving mass; it formed a distinct column moving upward, essentially untouched by the surrounding mass of cooler air. At a certain point the column would reach a zone of colder, drier air aloft that had much lower pressure. That was when the column would begin to spread out and cool. As it lost its heat and pressure, it would reach its dew point, and its water vapor would condense out to form a cloud.

  But now Espy’s mental image ran into an obstacle. This could not be all there was to the process. If the column dissolved at one particular altitude and stopped ascending, then the resulting cloud would simply spread out horizontally there like a pancake. Some clouds did in fact look that way, the ones Luke Howard called stratus clouds. So Espy’s model could account for them. But what about the towering cumulonimbus thunderheads? Where did the energy come from to form them?

  Espy was stymied. That was when he began to consider more closely the idea of how the water vapor condensed—in particular, its relationship to temperature.

  At that time, heat was still a mysterious concept. It was generally believed to be a physical substance contained and released by matter; that is, it was a subtle fluid, like electricity. The subtle fluid of heat was generally called caloric. (The concept survives now in the word “calorie.”) It was known that caloric had a curious property: it could be hidden. There was more heat contained within certain phenomena than could be perceived or detected with instruments. The detectable heat was known as sensible caloric (because it could be known to the senses); the hidden heat was called latent caloric. Some physical processes were known to release latent caloric, and one of them was condensation. When water vapor condensed, the surrounding air warmed up. This could only mean that its latent caloric had been freed.

  That idea was what led Espy through to his goal. He went back to his image of the rising column of air. When the column cooled and lost its water vapor to condensation, its latent caloric was released. As a result, the column would warm up, and, necessarily, it would begin to rise again. It would go up into higher and colder air; its dew point would once again be reached; more water vapor would condense; the column would continue to rise. At the most extreme, the end would be a monstrous column towering up to the upper atmosphere, shedding vast torrents of rain: a cumulonimbus thunderstorm.

  In other words, the atmosphere was a kind of universal steam engine, spontaneously creating columns of rising air that pumped warmth and humidity into the cold air aloft like pistons. Espy called this process “caloric rarefaction.” (This was the common term then for what is now called convection.) Then the clouds formed and the rain fell according to the simple and lucid principle of the dew point. Caloric rarefaction and the dew point fit together in a beautiful self-contained, self-sustaining process.

  That was the secret of the storm cloud, Espy declared: “steam power.” The idea hit him, he later said, like “an instantaneous transition from darkness to light.” He wrote: “A thousand contradictions vanished, and the numerous facts, a rude and undigested mass, which had been stowed away in the secret recesses of my memory, presented themselves spontaneously to my delighted mind, as a harmonious system of fair proportion.” Steam power, he wrote, “was the lever with which the meteorologist was to move the world.”

  Espy spent the summer in New Brunswick in a state of enthusiasm bordering on the manic. As he and Professor Alexander Bache, his friend from the Franklin Institute, walked the trail the tornado had left through the woodlands and into the town, he kept seizing upon curious windfalls and pointing out freaks of damage—fence posts driven into tree trunks, houses that had been upended, bedsheets off a laundry line that had been wadded up into the cracks in a crumbling brick wall. He seemed to grow more ebullient the more of the wreckage he saw. Everywhere he looked, he could discern a lucid pattern. The fallen trees, the ruined houses, the seemingly random dispersal of debris: they all suggested a single underlying process. The tremendous winds that had destroyed the town had all been rushing straight into the tornado funnel, and they had been drawn up through the funnel to staggering heights in the upper air. From the way the debris had rained back downward onto the landscape, Espy guessed the draw of the tornado had to be at least a mile high, maybe more. There could be no doubt about what this meant. Within the mysterious black funnel of the tornado, there was a rapidly rising column of air, exactly as his
theory of steam power had predicted.

  But as he considered the scene, he became convinced of something else. The eyewitnesses in the town were mistaken on one crucial point. They were all agreed that the tornado funnel had been spinning or rotating. Espy was sure this could not be correct. The tornado was not a spout or a whirlwind, as Franklin had thought it was. The winds were drawn into the central column from all sides in perfectly straight lines, like the spokes of a wagon wheel, and from there they rose up in perfectly straight lines through the clouds to the sky.

  His friend Bache heard him out as they wandered through the town and the surrounding countryside. Then he pointed out an obvious objection. Here and there, the tracks of damage clearly showed circular or spiral patterns. Espy dismissed this at once. The visible evidence was simply accidental. The movement of the tornado funnel would doubtless leave a confused and contradictory wake behind. It was clear to Espy that, viewed correctly, the underlying simplicity would shine through. Bache then brought up the problem of the sheer number of eyewitnesses—not only here, but in other accounts of the storm going back to Franklin and before. They all reported the cloud had rotated: How could they all be wrong? That didn’t faze Espy, either. Tornadoes were so rare, they appeared so suddenly and moved so quickly that nobody could be expected to provide a reliable description of what they’d seen.

  Bache, caught up in Espy’s enthusiasm, withdrew his objections and became a convert to the theory on the spot. Adding up all the evidence they saw in New Brunswick, he later wrote, “I think it made out that there was a rush of air from all directions, at the surface of the ground, toward the moving meteor, this rush of air carrying objects with it. The effects all indicate a moving column of rarefied air, without any whirling motion near the surface of the earth.”

  But Bache thought they needed another opinion, so they wrote to the Franklin Institute and invited another colleague to join them. This was the celebrated chemist Robert Hare. He was a notorious contrarian and would be, Bache thought, the perfect counterbalance for Espy’s fervor. There were few things that Hare liked to do better than argue with Espy; his highest satisfaction was the complete annihilation of some new idea of Espy’s that he found exasperatingly absurd.

  Hare arrived in New Brunswick in July. He followed the same paths that Espy and Bache had taken around town, through the ruined blocks of houses and the debris-strewn public squares and along the windroad cut through the forest. He examined the damage thoroughly and—he believed—objectively. He conceded that there was a lot of evidence for an inward rush of winds. And he accepted that the wide scattering of debris around the town and the countryside could probably be explained only by assuming that it had all been carried upward high into the cloud and then dispersed. His conclusion was that about many aspects of the tornado, Espy was probably right.

  But about Espy’s larger theory Hare was unconvinced. He was particularly skeptical about Espy’s claim that the tornado funnel didn’t spin. Some of the damage in New Brunswick, he wrote, “cannot be explained without supposing a gyratory force.” But he conceded that the spin might not be an essential element of the tornado’s behavior; it could be a local effect caused by chance variations in the inrushing winds.

  What was more serious for Hare was Espy’s belief that the updraft in the tornado funnel was caused by differences in temperature and pressure between the surface and the upper air—that is, the whole notion of steam power. He had already fought with Espy over steam power; it was obvious to Hare that caloric rarefaction simply wasn’t a powerful enough force to generate anything as large as a thunderstorm. He was beginning to work out a theory of his own, which was based on a new model of atmospheric electricity. Hare had found one piece of evidence extremely significant. On the far bank of the river was an area of downed trees where the leaves and the underbrush were all withered, as though they’d been flash heated by a swiftly moving flame. To Hare it strongly resembled the kind of scorching that one of his own electrical devices would have caused. He had always believed—and had frequently told Espy so—that electricity was the motive power of violent storms. This appeared to be proof. He left New Brunswick with the conviction that he had found the cause of tornadoes: the tornado funnel was a kind of conduit through which an extraordinarily powerful electrical current was flowing.

  “I conceive,” he wrote, “that the inevitable effect of such a current would be to counteract within its sphere the pressure of the atmosphere, and thus enable this fluid, in obedience to its elasticity, to rush into the rare medium above.” In other words, Hare thought the electrical current flowing up the tornado funnel would be surrounded by a vacuum, which would draw a violent inflow of air from the surrounding atmosphere up with it into the higher altitudes. “After maturely considering all the facts,” he concluded, “I am led to suggest that a tornado is the effect of an electrified current of air, superseding the more usual means of discharge between the earth and clouds in those sparks or flashes which are called lightning.”

  There was another investigator at New Brunswick. His name was William Redfield. He was another amateur enthusiast of the weather, with no scientific training; he was a successful businessman who ran a steamship company. He was uncomfortable around the other, more philosophically inclined tourists and stayed aloof from them. During his days in New Brunswick, he and his son made their own way along the debris trail and through the forest, taking their own measurements of the wrecked buildings and fallen trees, and they said nothing to anyone about their results.

  Redfield was looking for evidence for his own pet theory about the tornado. This was a notion that he’d been investigating now for almost fifteen years. He’d come upon it not through speculation and book learning, as Espy had done, but through a fluke occurrence during the greatest tragedy of his life.

  In 1821, Redfield had been a storekeeper in the small town of Cromwell, Connecticut. He had recently remarried, after losing his first wife to a prolonged illness. His new bride, Lucy, had almost immediately become pregnant; the birth had been a calamity, the child had died after two days, and Lucy had gone into a steep and irreversible decline.

  One day that September, a few weeks after the loss of the baby, as Redfield was sitting with the bedridden Lucy, a gigantic storm had come over their town. Redfield had never experienced anything like it: his misery over his wife’s deteriorating health was temporarily dwarfed by terror at the fury that was engulfing them. It was hour after hour of banshee winds, torrential rains, and cannonading thunder. Afternoon gave way to the evening, and the storm, to Redfield’s disbelief and horror, kept getting stronger. It didn’t peter out till after midnight, when it left a disconcertingly placid starlit sky in its wake. For decades afterward, people in Connecticut called it “the Great September Gale.”

  Lucy died two weeks later. A few days afterward, Redfield traveled to the town of Stockbridge, Massachusetts, to visit her parents. He wanted to return to them some of her belongings and tell them the story of her last illness. Stockbridge was seventy miles away, which was a two-day trip. Redfield took his oldest son, John, with him; John in his memoirs would describe it as the strangest journey of his life. The signs of the gale’s passage were everywhere. Farmhouses were wrecked and fields were sodden ruins; the roads were washed out for long stretches and were blocked every few hundred feet by downed trees. But what John found most memorable was his father’s behavior. Redfield slowly stirred out of his melancholy as they rode. He became curious about the ruined scenes around them; then he was fascinated; by the end of the journey he was obsessed.

  What exactly had been the nature of the gale? The more of its aftermath Redfield saw, the odder it all seemed. In the immediate neighborhood of their home, the trees appeared to have been knocked down by a gigantic wind blowing from the southeast, off the Atlantic. But inland, they could see that the trees had been downed by an equally strong wind blowing in the opposite direction, out of the wilderness country to the northwest. How was that p
ossible? Did the windstorm come ashore, push inland, and turn around and come back?

  At each stop they made, Redfield interrogated the locals. He heard the same thing everywhere: no matter which direction the wind had been blowing, the storm that night had hit its peak at around nine o’clock. That was Redfield’s memory as well: he had passed that evening watching helplessly over Lucy and listening to the clock tick in the rare lulls in the storm, and he had noticed that the wind had reached its most demonic fury exactly at nine.

  But this seemed impossible. It required believing that there had been two storms, equally strong, passing each other in opposite directions, each reaching its peak at the exact same hour. He kept turning this mystery over and over in his mind, and he couldn’t make the slightest sense of it. The whole way home from Stockbridge he kept remarking to John how strange it was. John listened to him with only the dimmest sense of what he was talking about. But John did remember quite vividly how it ended. Just as they were approaching their house in Cromwell, his father abruptly fell silent.

  He remained silent the rest of the way home. He said nothing more to John about it after they arrived. He didn’t talk about it to his friends. He said nothing about it to anyone for the next nine years. But he had just had the most startling idea of his life.

  He didn’t unburden himself until a summer day in 1830, when he happened to be riding a steamboat on its regular shuttle from New York City to New Haven. He learned that one of the other passengers was someone whose name he recognized: Denison Olmsted, professor of mathematics and natural philosophy at Yale University. He immediately sought Olmsted out, introduced himself, and launched into an impassioned speech about hailstorms. It was an unusual opening for a conversation, but Olmsted was perfectly delighted to talk about hailstorms. He had just published a paper in the American Journal of Science outlining his theory about how hail was formed. He believed that hailstones were raindrops that passed randomly from domains of warm air to domains of cold air, until they froze in flight and fell to the earth. Redfield had read the paper and wanted to know if such pockets of cold air really existed throughout the atmosphere. Olmsted pointed out that the high mountains in India had snowcapped peaks. Redfield quoted some obscure travelers’ tales he’d read about unusual weather in the tropics. And so, as the steamboat glided on, the two men became more engrossed in talk and speculation about hail, clouds, lightning, and storms.