The Big Engine That Couldn’t
Tuesday, January 11, 1853, dawned clear and chilly, but despite the cold, Battery Park in lower Manhattan was thronged with curious spectators waiting to see the trial run of the Ericsson , a great ship powered not by wind or steam but by “caloric”—hot air. History was in the making; the Age of Caloric lay just ahead.
For months American and European newspapers had been running stories about Capt. John Ericsson and the progress of his ambitious vessel with its huge engine. As an energy source caloric promised everything steam couldn’t. For the preceding year it had been widely promoted as safe, quiet, clean, efficient, and economical. Almost everyone at dockside looked forward to its replacing steam.
Caloric was an eighteenth-century term for what we now know as thermal energy, or heat. The theory of caloric portrayed it as a fluid that could be transferred from one substance to another. By the mid-nineteenth century that theory was becoming obsolete, and the modern science of thermodynamics was being established. Yet in various modified forms caloric theory still had its adherents.
Captain Ericsson believed in a “grand principle”: that heat in the form of caloric could be used over and over without losing its ability to perform work. Some recent discoveries were beginning to call his grand principle into question, but that meant little to Ericsson. Thermodynamics was a very new science, and its laws weren’t fully established and accepted. His chosen medium for generating power was heated air. In his vision, after performing work —say, by moving a piston—heat could be captured and recycled inside a regenerator. It seemed reasonable to many at the time, and on that winter morning in 1853, if all went according to plan, Ericsson’s name would take its place alongside those of Watt and Fulton.
The public placed just as much hope in caloric as Ericsson did. People very much wanted his engine to succeed. Too often steam engines had bitten—or scalded or blown off—the hands that fed them. Steam dominated the industrialized world as the primary source of power, but though it was very widely used, it was not nearly so widely loved. Almost everybody knew of someone who had been maimed or killed in a steam explosion. The newspapers ran reports of boiler accidents nearly every day, and steam pipes burst with monotonous regularity. By the mid-nineteenth century, even when they weren’t dodging boilerplate or vented steam, engineers and bystanders were constantly aware of the murderous, hissing, booming, earth-jarring, foul-smelling unpredictability of steam contrivances.
Captain Ericsson’s marvelous ship would demonstrate a much gentler, superior way to generate power. Ericsson’s scheme promised a low-pressure engine that would pose no danger of explosion. The power plant being stoked in the belly of the Ericsson was the largest ever built, a monstrous thing that occupied a quarter of the length of the 250-foot craft. The gargantuan engine ran by the expansive force of hot air, which, according to Ericsson, was the energy source of the future. Hot air and the power of caloric would relegate the steam engine to the scrap heap. He repeated this belief with such conviction and regularity that many people began to believe it.
Reporters found John Ericsson a colorful and thoroughly absorbing subject for interviews. They enjoyed his contagious enthusiasm, and, like the public at large, they wanted to believe what he was telling them.
Ericsson realized that when the moment came, more than just his ship would be on trial. His entire presentation—how he got his message across—would be equally important. He put tremendous effort and planning into creating the proper mood during the Ericsson ’s maiden voyage. He envisioned the whole affair as what today we would call a media event. He had been refining his explanation of how the engine worked, and he made sure that the reporters in attendance would have plenty to write about.
So on that momentous, frosty morning in 1853, the press, along with a mélange of Ericsson’s personal friends and financial backers, several New York politicians, scientists, and business notables, all jostled up the gangplank, eager to board the impressive, gold-trimmed, gleaming white side-wheeler. Almost everyone—those aboard and those wishing they were—looked forward to seeing history made.
One of the few skeptics at Battery Park was Orson Munn, the twenty-nine-year-old co-owner and editor of the fledgling Scientific American . Munn’s principal occupation was patent solicitor. He published Scientific American partly as a promotional organ for client investors who paid him to publicize their devices and help them raise money. Munn was at odds with Ericsson because Ericsson was getting plenty of publicity and money without Munn’s help.
In fact, Ericsson had a volunteer fund-raiser in the person of John B. Kitching. The forty-year-old, British-born Kitching had made a small fortune importing and exporting goods between the United States and Britain. His business background gave him a solid sense of what would sell, and technology appealed to him. Kitching had already helped Samuel F. B. Morse raise money for the telegraph and would later aid Cyrus W. Field in making a commercial success of the transatlantic cable. For the moment John Kitching believed so fervently in Ericsson’s caloric ship that he had put $150,000 of his own money into it, and raised an equal amount from others, to cover the cost of casting and assembling the huge engine.
Since neither Ericsson nor Kitching had asked for help from Scientific American , the entire caloric program had become the object of Munn’s editorial scorn. “How can it be possible for hot air to propel an engine and still save the heat of the air?” he wrote. Munn especially chided journalists who endorsed the idea of caloric with blind faith: “When they touch upon scientific matters, they utter the most consummate nonsense.” Munn wasn’t invited to the first voyage of the Ericsson , but he managed to slip aboard anyway.
The dignitaries and newsmen, about sixty in all, looked over the luxurious, gleaming ship and then sat down to a sumptuous breakfast in the Ericsson ’s grand saloon as it began its voyage. Amid cheers from the dockside crowd, the Ericsson cast off and headed out toward Fort Diamond (now Fort Lafayette), Brooklyn, some seven miles away. There the big white ship would turn around and come back. The entire journey would last two-and-a-half hours.
After the newsmen had tucked away their victuals and drunk their wine, Ericsson and a colleague, Professor James Mapes (a former president of the Mechanics’ Institute of the City of New York), launched into an elaborate, illustrated explanation of how the ship’s huge hot-air engine worked, with the aid of hinged pasteboard models. (See box on page 44.) During his speech Mapes said, “I consider there were but two epochs of science—the one marked by Newton, the other by Ericsson.”
Despite Mapes’s effusive praise of the caloric engine, John Ericsson is best remembered today for designing the U.S. Navy’s first iron-hulled warship, the Monitor , which earned instant fame in its battle with the Confederacy’s Merrimack , at Hampton Roads in 1862. A But Ericsson had proven himself a prodigious inventor and engineer long before the Civil War.
Ericsson was born in Längbanshyttan, Sweden, in 1803. His father, a college-trained mathematician and self-taught scientist, worked as a mine inspector and later as chief explosives engineer for the construction of part of the Göta Canal across Sweden. John Ericsson found himself surrounded by heavy-construction machinery as an eieht-year-old, and it fascinated him. He designed and built working models, including a tiny sawmill and a miniature water pump. Because there was no real school at the Göta Canal work site, Ericsson’s father and his colleagues taught young John mechanical drawing, mathematics, English, and chemistry.
The Göta Canal’s chief engineer, Count Baltzer Bogislaus von Platten, became acquainted with John Ericsson, admired his knowledge of and enthusiasm for things mechanical, and enrolled the youngster in a course in map making. When John returned, he began making relief maps for the canal’s excavation sites. He did so well that Count von Platten promoted him to assistant leveler at the age of thirteen. That job, like his father’s, entailed deciding where to blast. By the time he was fourteen, according to an early biographer, he was in charge of six hundred workmen engaged in blasting and earth moving.
At seventeen Ericsson joined the Swedish army. His first job was as a surveyor. He was paid a set amount for each sector covered, and he worked so fast that he had to be listed as two men on the rolls of the regiment to keep his pay from looking excessive. Ericsson also showed an interest in cannon and gunnery, and during his military service he built his first working hot-air engine. He wrote up the engine in a paper that he sent to the Society of Civil Engineers in London. The society encouraged Ericsson to come to England; he took a leave from the army and sailed to London.
Unfortunately, when he tried to demonstrate his hot-air engine to the society, he fueled the working model with British coal instead of the pine shavings he had used in Sweden. The coal put out much more heat than the pine, and the engine overheated and jammed. Ericsson’s embarrassment may well have been responsible for the care and planning he put into demonstrating his hot-air ship many years later.
In London, at the age of twenty-three, Ericsson became a partner in an engineering firm, Braithwaite and Ericsson. The partnership thrived and found steady customers for its steam fire engines, pumps, and refrigeration equipment. During a decade with Braithwaite, from 1826 to 1836, Ericsson invented and made prototypes of a desalination machine, a k new type of mine pump, an ocean sounding device for ships, a power-transmission system using compressed air, a machine for cutting files, a self-acting gunlock, and several different types of furnaces. Braithwaite and Ericsson took out some thirty patents—most of them in John Braithwaite’s name.
Perhaps the two most lasting and important inventions of Ericsson’s London years were the surface condenser for steam engines and the successful application of the screw propeller to ships. Unfortunately, the British admiralty, despite a successful demonstration, wouldn’t accept the screw propeller, preferring to stick with the tried-and-true paddle wheel (though they changed their minds a month later when presented with a screw-driven ship designed by a British native).
Even worse luck dogged Braithwaite and Ericsson when they entered the Rainhill competition of 1829, sponsored by the Liverpool and Manchester Railroad, to design and build a lightweight, high-speed railroad locomotive. Their entry, the Novelty , proved faster than any of its rivals, but its engine broke down after several speedy trials. The L&M’s directors, anxious to protect the interests of their employee George Stephenson and his Rocket , disqualified the Novelty . The loss was a blow to Braithwaite and Ericsson, and after spending much money on the unsuccessful attempt to sell the British navy on screw propulsion in 1836, the firm went bankrupt.
In 1839, aged thirty-six, after serving time in a debtors’ prison (the result, in part, of extravagant spending on clothes), Ericsson decided to leave England for the United States. His new wife, the former Amelia Byam, was already growing tired of her husband’s haphazard lifestyle and chose to stay behind. She would later join him briefly in New York before returning to London, where she would spend the rest of her days.
Ericsson saw a market for his screw-propeller innovations in the steamers that were plying America’s inland waterways, and he had a promise of a contract with the U.S. Navy to design a propeller-driven steam frigate. That ship turned out to be the ill-fated Princeton , whose trials in 1844 were marred when a gun not designed by Ericsson exploded, killing two cabinet members and several other prominent guests. Despite this accident the Princeton holds an important place as the first screw-propelled warship.
Soon Ericsson had established himself as a ship designer, and he returned to an idea he had been working on sporadically since his days in the Swedish army: the caloric engine. Prospects of introducing it successfully seemed dim at first. All the fastest, most powerful machines of the day were steam-driven: ships, locomotives, sawmills, pile drivers, and the great dredges that scooped out canals.
But as steam engines grew ever bigger and more powerful, boiler technology and metallurgy failed to keep up with the demands for greater steam pressure. Horrific explosions were common. (See “The Future of an Explosion,” Invention & Technology , Spring/Summer 1989.) Codes were passed setting standards for safe operation; however, many owners of steam machinery found that boiler inspectors could be bought more cheaply than better hardware, so laws alone did not solve the problem, and safety remained a major consideration in steam-engine design and operation. If Ericsson could build a practical caloric engine that equaled the power of steam but ran more cheaply and less hazardously, the commercial possibilities would be limitless.
Hot-air engines weren’t new with Ericsson. They had already been around for years when he began tinkering with them as a teen-ager. Various people, most notably Robert Stirling, had designed and built experimental models in Britain early in the century. But they had never caught on for most uses because, as Ericsson realized, in their traditional form they weren’t very efficient—that is, they did not produce a large enough amount of energy per unit of fuel.
Ericsson thought he knew why: After the air passed through such an engine, it was exhausted while still warm, giving up its caloric to the atmosphere and wasting reusable energy. So he added an extra fillip, the regenerator, to his working model. The principle of the regenerator was not new either; it had been used in previous hot-air engines, for example. Nor is the idea of capturing “waste” heat unreasonable. Heat exchangers employing the principle were used in condensers and blast furnaces of the day and can still be found in modern power plants. It all seemed quite plausible to Ericsson, and he pursued and refined his vision with all the determination that he had brought to his myriad other inventions. But his scheme had two major flaws.
First, Ericsson regarded the heat used to expand air in the working cylinder as only a marginal loss, analogous to something like friction. Apparently he was not aware that the first law of thermodynamics, which was gaining currency in the late 1840s, states the equivalence of heat and work. That is, when a medium—in this case, air—does work in an engine, some of its heat is converted to work and no longer exists as heat. Also, he believed that all the heat not lost by expansion of the air, or through conduction, could be recaptured and used again. That violated the second law of thermodynamics, which was just beginning to be understood by those at the forefront of engineering. Today the impracticability of Ericsson’s engine seems clear, but in 1853 it was much less so. At a British symposium held that year to discuss the caloric engine, some skepticism was expressed, but very few of the distinguished engineers in attendance flatly denied that it could work. And to the guests assembled for the Ericsson ’s gala trial run, such abstruse scientific matters were of little or no concern.
Once the ship was under way, reporters and dignitaries were allowed to inspect the engine room. It was tended by just one engineer and one fireman, whose surroundings were cool enough and whose job required little enough exertion that he had to wear a light jacket against the cold. As promised, the hot-air monster was pumping away in virtual silence, the ship’s crankshaft turning at nine revolutions per minute. The undersides of all four working pistons stood exposed, facing upward, rising and falling at a leisurely rate inside their cavernous cylinders. Ericsson invited his guests to step onto the smoothly gliding pistons and take a ride. Most did. And what fun! The journalists were soon having the time of their lives. Ericsson had pulled off a public-relations masterstroke.
When the Ericsson finished the journey and docked around noon, the guests returned to the saloon to pass florid resolutions congratulating Ericsson and his associates (and to enjoy more food and wine). The festive mood was broken temporarily when one guest, upon disembarking, turned and shouted over his shoulder, “Vive la humbug!” The crowd fell silent. But then Professor Mapes retrieved the situation by shouting back, “Here’s a man proposing his own health!”
The next morning’s newspapers all sang Ericsson’s praises. Charles A. Dana of the New York Tribune captured the general mood when he wrote, “The age of Steam is closed; the age of Caloric opens. Fulton and Watt belong to the Past; Ericsson is the great mechanical genius of the Present and the Future.” The New York National Democrat said, “In ten years, we predict, steam will be only a venerable reminiscence.” And the editor of a collection of articles about the event, which was published soon afterward, breathlessly asserted that “the work of the inventor is complete ; nothing remains to be devised, and little even to be improved or perfected.”
Yet for all the praise, the Ericsson had shown one serious flaw, and Ericsson was painfully aware of it. The ship was just plain slow, too slow to compete with the oceangoing steamships of the day. The Ericsson had barely managed 6.5 knots. Collins liners routinely crossed the Atlantic at 14 knots, using big, two-cylinder, double-acting steam engines rated at 2,000 to 2,300 horsepower. No one ever tested the Ericsson ’s caloric engine for power output, but calculations in Ferguson’s 1961 paper put the figure at around 250 hp. Ericsson estimated the engine’s output at around 600 hp, but he was the only one so sanguine. Other contemporary estimates ranged from 116 to 316 hp.
Ericsson said during the demonstration that the Ericsson ’s maiden voyage hadn’t been intended as a speed trial. A few changes in the engines, he said, and it would be able to compete with the big steamers. But the problem facing Ericsson was much greater than he realized. Because of frontal area and hull friction, to double his ship’s speed he would have had to octuple the engine’s power output. To do that, the cylinder castings would have to either withstand much greater pressures or grow tremendously in size.
Neither alternative seemed feasible. The sealants and lubricants of the day didn’t allow cylinder pressures anywhere near what would be needed. And even if casting technology had allowed cylinders and pistons to be made big enough, the engine by itself would have dwarfed any known ship. The gentle hot-air engine could not provide the massive brute force needed to push a large bulk through the water. Nor had the Ericsson ’s hot-air engine shown itself superior to steam in fuel economy; it used no less fuel than a steam engine of the same horsepower.
Perhaps Ericsson could not even admit those facts to himself at first, but he must have had an inkling that the Age of Caloric had died aborning. A month after the demonstration voyage the vessel sailed to Virginia, ostensibly for adjustments to her engine. Munn soon wrote sarcastically, “We are patiently waiting for the New York Times and Tribune to tell the exact day—seeing the days of steam are numbered—when all our steam-boats will stop running.”
John Kitching arranged for President Millard Fillmore and President-elect Franklin Pierce to inspect the Ericsson at her anchorage off Alexandria, Virginia. Secretary of the Navy John P. Kennedy was impressed by :he captain and his caloric ship, and he soon sent a memo to the House Committee on Naval Affairs suggesting that half a million dollars be set aside for a huge hot-air-engined frigate to be designed and built by Ericsson. It seemed a good idea at the time, especially while publicity was still favorable, or at least not totally unfavorable. But Congress denied Secretary Kennedy’s request.
Meanwhile, Scientific American kept hammering away at the caloric ship’s disappearance. “Where is the Ericsson ? Let the Truth be Told about the Ericsson .… We make this prediction, that in three years, perhaps less, a hot-air engine in a ship will be among the things that were.” Munn’s fellow journalists also began to have doubts about the Age of Caloric.
The Ericsson finally reappeared in 1854, outfitted with a redesigned and even less powerful hot-air engine. It was said to be more efficient, but details were never published. Its supposed efficiency probably had to do with a redesign of the regenerator. As it turned out, though, no matter what Ericsson did, he would never be able to increase power enough to make hot air competitive with steam.
And as luck would have it, on April 27, 1854, the newly outfitted Ericsson was caught with her hatches open in a sudden squall off Jersey City and sank in water eight fathoms deep. No one was hurt. The great white-and-gilt liner was eventually refloated and fitted with a steam engine. The Age of Caloric had come and gone.
After giving up on the Ericsson , the captain returned to the familiar world of steam power. He designed an ironclad warship in 1854 and offered it to Napoleon III, but the emperor was not interested. When the Civil War broke out, Ericsson was able to expand on that design to produce a similar ship for the Union Navy, the famous Monitor . He continued his work on ship design and naval ordnance through the 1860s and 1870s while investigating various topics in astronomy and other scientific disciplines.
Through it all, Ericsson kept up his search for an engine that would provide a plentiful source of power without all the inconveniences associated with steam. He came up with ideas using solar energy, tides, and electricity, but to his death, in 1889, he continued to believe in caloric power. Hot-air engines did eventually find a niche, but not in large-scale applications like ships, where their basic problem—low power output—negated any possible advantages they might have over steam. For small-scale, stationary applications, however, where not much power was needed, hot-air engines became quite popular.
Over his last several decades Ericsson made a nice income from licensing his designs for small (usually fractional-horsepower) “domestic” hot-air engines. These filled a number of functions. They ran printing presses and sewing machines, pumped water, and performed all sorts of farm chores. Hot-air engines (designed by Ericsson and many competitors) were much quieter and safer than steam, could use any type of fuel, and needed very little attention once started. Even Scientific American hailed the utility of small-scale hot-air engines as early as 1860: “A motor is needed less powerful than the steam engine, and it seems altogether probable that the air engine is to supply this great want.… The mind is lost in the effort to imagine the endless variety of uses which there are for a small and cheap motor.” Many kept running well into the twentieth century.
Ericsson’s career was marked by three famous ships: the Princeton , the Ericsson , and the Monitor . The Princeton and its progeny eventually proved their worth despite the initial fiasco, and the Monitor was crucial from its very first days in the Union’s establishment of naval superiority. The Ericsson , by contrast, began to fizzle as soon as its maiden voyage was over.
Every great inventor seems to have at least one episode in his career where he overreaches himself, and Ericsson, with his decades of practical training and experience, cannot be blamed for discounting new, often unclear theoretical results. Still, despite his great capacity for both inspiration and perspiration, Ericsson could not make a type of engine best suited for running dentists’ drills propel a giant ocean liner. For all its inconveniences, steam would remain supreme until the advent of electric power and internal combustion nearly half a century later.