The Magnetic Blacksmith from Brandon
edited: Monday, October 29, 2012
By Richard J. Bauman
Not "rated" by the Author.
Posted: Saturday, October 24, 2009
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There are few things worse than being ahead of the times with an idea. Thomas Davenport, inventor of the electric motor, was just such a person.
Thomas Davenport climbed into his brother Oliver’s horse-drawn wagon, and they headed for Crown Point, New York, 25-miles from their home in Brandon, Vermont. Neither man knew, or even considered, they were setting off on a life-changing, world-changing journey that day in 1833. But they were. And a less likely pair of agents for science and technological change would have been hard to find. Oliver was a traveling peddler of pots and pans, while Thomas was an uneducated blacksmith. Nonetheless, the events their expedition precipitated would ultimately change history.
Unless you’re Amish, or a hermit, it’s unlikely that you get through any day without using dozens of electric motors. If you shave with an electric razor, made a smoothie in your blender, cleaned your carpets with a vacuum cleaner or work in an air-conditioned office you benefited from electric motors. And the workings of all of those motors have their genesis in the first one, which Thomas Davenport invented.
Early in 1833, Davenport had heard the Penfield and Hammond Iron Works in Crown Point, had a Galvanic Battery, which could “suspend an anvil between heaven and earth.” He just had to see it.
Actually, the mysterious device wasn’t a battery, but rather an electromagnet invented a few years earlier by Professor Joseph Henry when he was at Albany Academy. There were only a few electromagnets in the world and the one at Penfield and Hammond was a soft iron horseshoe shaped object, about a foot long and wound with silk-insulated copper wire. It was connected to a crude wet-cell battery, which powered the magnet.
At the Penfield and Hammond Iron Works permanent magnets were used to separate iron from the local low-grade ore. Their magnetism diminished with use, and the electromagnet was used to re-magnetize them.
The Davenport brothers were in awe when they watched the electromagnet pickup or “suspend” a small anvil “between heaven and earth.” Thomas spit out questions about the magnet: How much did the magnet weigh? Three pounds. How much did the anvil weigh? A hundred and fifty pounds. If a wire from the battery to the electromagnet were cut, would the anvil drop to the ground? Yes, it would.
“Like a flash of lightning,” he said later, “the thought occurred to me that here was a marvelous power. If three pounds of iron and copper wire would suspend 150 pounds in the air, what would a 300-pound magnet suspend?” He reckoned such power could be better used than for reinvigorating the ironwork’s magnets and playfully suspending an anvil in midair.
Thomas wanted to buy the magnet, and the ironworks owners’ were amiable to his proposal—provided he had $75 cash. The brothers had a little money, but after and excited and animated consultation, Thomas convinced Oliver to sell his tin wares to raise cash. Then Thomas traded their horse for a lesser steed and a few dollars, to make up the $75 fee.
When Oliver and Thomas got back to Brandon, it was nearly 11 p.m., but Thomas wasn’t tired. His mind was a frenzy of curiosity. He wakened his wife, Emily, and asked her to get paper and a pen and join him in his workshop. In the glow of a couple of oil lamps, and to his wife’s and his brother’s dismay, he started to unwind the copper wire from the magnet. Oliver begged him not to do it. He argued that they could exhibit the magnet, demonstrate its power and by charging admission recoup their $75.
Thomas either wouldn’t or couldn’t stop. He had to learn how it was built. As he dismantled the magnet, Emily wrote down the minutest details of its construction—the number of windings, the length of the copper wire and the like. When he finished, Davenport felt triumphant. He knew how the electromagnet worked, and perceived the raw power it held—and he seized on the idea of building “an electromagnetic engine.”
He became obsessed with capturing the dynamic power of electromagnetism. He became “too busy” experimenting with magnetism to shoe horses or make tools for local farmers. Some thought he was working on a perpetual-motion machine, others thought he was a bit loony, all were frustrated and took their business to his competitors.
Davenport’s behavior struck family, customers and neighbors as bizarre. He was a talented blacksmith and he had built a thriving business. He and Emily had every reason to expect a comfortable life with a modest level of security — something he never had as a youth.
Davenport was born on a farm in Williamstown, Vermont July 9, 1802. His father died when Thomas was ten years old, and he was plunged into a life of drudgery and poverty. He had to work like a man—laboring on the farm from dawn to dusk. He went to school sporadically, and his formal education didn’t total more than two or three years.
He was apprenticed to a blacksmith at age 14, and worked without pay, learning the trade, until he was 21 years old. He often read books about science and inventions while he pumped the forge’s bellows; raising its temperature and getting pieces of steel red hot and ready to be hammered into tools and other objects.
When his apprenticeship ended, Davenport opened his own business, and for ten years stuck to it—until he heard about Professor Henry’s amazing electromagnetic device.
The morning after he and Oliver had returned to Brandon with the electromagnet, Davenport began building a magnet many times larger that the one he bought. Then he set out to capture the power of magnets and electricity, and put it to use in some way, so it would run machines.
Davenport magnetized an iron bar and mounted it lengthwise on a pivot at the bar’s center, so it could revolve on the pivot point like a compass needle. When he set up his electromagnet near it, the bar rotated but stopped when its negative pole was aligned with the electromagnet’s positive pole. He realized that if he could break the current before the bar stopped rotating, its momentum would carry it around until its pole came again within the pull of the electromagnet.
He and Emily spent hours trying to do this by hand, but they couldn’t break the current quickly enough to prevent the bar from stopping. Eventually, they rigged little cups of mercury as part of the electrical circuit from the battery to the magnet. They could cut the power almost instantaneously by jerking one of the wires out of a cup. It took practice, but finally they succeeded in making the magnetized bar rotate on its pivot. Davenport had proven to himself that an electromagnet could be used to turn a wheel.
Orange Smalley, A 22-year-old wheelwright was excited by Davenport’s prediction that magnets would soon be used to power machinery. Smalley offered his savings for the purchase of materials to further Davenport’s research. In July 1834, just seven months after his introduction to electricity, Thomas Davenport, using intuition and material scraps, had built an electric motor. He mounted a wheel to the motor, and the wheel made 30 revolutions a minute. It was crude and feeble, but it was also the genesis of every electric motor in the world today.
Seeking someone who might understand what he was trying to do, Davenport and Smalley hauled the motor by cart to Middlebury College, twenty miles away. They set up the machine in the village tavern, and Davenport muscled up the courage to visit Professor Turner, teacher of “natural philosophy” at the college.
Turner saw the motor, and declared: “You have invented nothing less than a new motive power.” Turner wrote a letter of introduction to Professor Amos Eaton of Rensselaer Institute and recommended a book to Davenport whereby he could learn more about electricity.
Elated and encouraged by Turner and Eaton’s reaction, Davenport went home and built a stronger motor. His crude, mercury-cup commutator was no longer fast enough, so he hammered the contact wires into thin springs that rubbed against the shaft of the wheel. When segments of the shaft were insulated, the wires reversed the current automatically, thus providing the positive and negative impulses, which kept the wheel spinning. This was the origin of the “brush commutator” commonly used in motors.
Cash and credit were running low, and Smalley became discouraged at the snail-pace progress of the project. He withdrew from the venture. Davenport worked on, alone, constantly improving his design. Six neighbors, sufficiently impressed with his motor, pooled their resources and financed Davenport’s journey to Washington, D.C., to obtain a patent for his motor.
Davenport went first to visit Professor Eaton, and Eaton sent him to see Professor Henry, who had moved on to Princeton University. Henry, in turn, sent Davenport to Philadelphia, to exhibit his motor at the Franklin Institute. These excursions ate up his funds, and he had just enough money to get back to Troy. He arrived at Professor Eaton’s house penniless.
Davenport sold his motor to Eaton and the Rensselaer Institute for $50, so he could get back to Brandon. It was a discouraging trip home. He had neither patent nor motor. Destitute and discouraged, his father-in-law persuaded him to give up his electric motor dream and go back to his forge. Davenport reopened his blacksmith shop, but his heart wasn’t in it. The thought of creating electric motors possessed him. He had started something that could not be ignored.
In the meantime, professor Eaton had written an article about the motor. Professor Silliman of Yale had prepared an enthusiastic paper for a scientific journal. Then a New York newspaper published an article challenging the notion of an electric motor. The story offended Eaton and Silliman. Eaton, without consulting Davenport, announced the inventor would demonstrate his motor in the Troy courthouse on October 1, 1835, which was only a few weeks away.
Davenport refused to participate. He told Eaton he had no money to buy materials to build a new motor. Eaton ignored the objections. “You have involved friends and it is your duty to support their pledges,” he wrote. He then bought all the copper wire in Albany and shipped it to Davenport. He had no money to buy silk for insulating the wires, so Emily tore her wedding dress into strips and they wound the wires of the new motor with it.
The exhibition in Troy vindicated Eaton and Silliman, but Davenport benefited not a wit. One spectator at the demonstration, a young mechanic from Cabotsville, Massachusetts invited Davenport to come and work in his shop. The two men built a circular electric railway three feet in diameter. The powerhouse stood in the center, and a miniature locomotive sped around the track. But his new comrade was in no position to go further, and once again, Davenport was alone, and without funds.
He tried to support his family by giving exhibitions of his electric motors, and during a two week run at Saratoga, New York, he met Ransom Cook, a prosperous manufacturer. With Cook’s help, Davenport built another electric motor. For the second time he went to Washington for a patent, but disaster followed him like a shadow. The patent office burned and his model was destroyed in the conflagration.
Cook and Davenport built yet another motor, and on February 25, 1837, Davenport obtained U. S. Patent No. 132, the world’s first patent for an electric motor.
Dazzling publicity followed. Newspapers predicted—half a century prematurely—a revolution in industry and transportation. A New York promoter interested Cook in a stock-selling scheme, promising the partners an initial payment of $12,000 within 30 days. They moved their workshop to New York, where the Herald proclaimed the invention “the greatest the world has ever seen, or will see.” Famous men came to view the new marvel, among them Samuel Morse, then working on his telegraph.
Months passed and the partners received no money. Cook went home, and Davenport resumed his breadcrumbs existence, subsisting by giving exhibitions of his toy electric railway. An economic depression had swept the country and capital was wanting.
He launched a small magazine, The Electro-Magnet and Mechanics Intelligence, which was devoted to the marvels of electricity. He drove the printing press with his own one-half horsepower “electromagnetic engine.” It was the first useful task ever performed by an electric motor. The magazine failed.
There was one more false dawn for Davenport, before the final darkness. An Ohio investor offered him $3000 to help develop his motor. But the money was in Ohio bank notes, and as luck would have it, the bank failed. That was it for Davenport. He collapsed with a nervous breakdown.
He returned to Brandon, and his waiting family, and tried blacksmithing again, but the work too strenuous. He and Emily settled on a small farm in Vermont, where he decided to write his memoirs. Emily wrote down his dictated and disjointed rambling account of his invention.
Thomas Davenport died in Salisbury, Vermont in 1851, three days before his 49th birthday. The patent on his electric motor had expired, and he never reaped the rewards of his incredible invention—but others would.
Davenport’s electric motor concept was genius, but it was ahead of its time. The limiting factor for electric motors during his lifetime was the lack of a dependable source for continuous electric current. Batteries were unreliable, but the only source of electricity that he knew of.
Had Davenport recognized one fact about his motors, experts say he would have changed history even more dramatically than he did, and would have cut the age of steam by 50 years or more. What was the elusive concept? The principle of his motor could have been reversed. What Davenport couldn’t see, and what would take others twenty years more to learn, was that his motors could be turned by water or steam power and they would generate electricity.
Less than 40 years of his death, electric-powered trains and trolleys became commonplace in major cities. With Davenport's machine creating electricity at a power station and his motors aboard the trains and trolleys converting this electricity, transmitted by power lines, to mechanical energy a new era of transportation was born.
In 1882, Thomas Edison’s Pearl Street station in lower Manhattan used steam engines to drive shunt-wound brush and commutator dc generators of the type that Thomas Davenport had invented 45 years earlier. Recognizing that expanding demand would require a massive new manufacturing and service industry, Edison started a manufacturing facility in Schenectady New York that would become the General Electric Co. The company's first products were motors and generators that copied the design and principles of Davenport's motor.
Thomas Davenport, the uneducated blacksmith from Brandon, was a bridge between the age of muscle power and the era of electrical machinery. He was one of the first to recognize that electricity could, and would, change the way we work and live. He was one of the founders of modern technology. Yet, unlike Edison, Fulton, Ford and other giants of technological change, hardly anyone recognizes the name Thomas Davenport, the blacksmith from Brandon, the inventor of the electric motor.