Some inventions are so ahead of their time that no one appreciates them until long after their inventors’ lives have ended. Today, for example, electric motors, which convert electrical energy into mechanical energy, power our vehicles and appliances such as refrigerators, fans, washers and dryers. But there was a time when the motor was little more than a curiosity.
In the early 1800s, Michael Faraday and a small number of other scientists built machines that demonstrated the basic principles of the electric motor. A blacksmith from Vermont named Thomas Davenport, an unlikely pioneer in the nascent field of electromagnetism, was one of the first to try to make money off the contraptions. The attempt financially ruined him. When he died in 1851, his dream of locomotives and large machines run by electricity was still unrealized.
Davenport first became interested in electricity and magnetism when he heard about a magnet-based machine built by Joseph Henry used to separate iron ore. Davenport’s interest was so aroused that he journeyed about 25 miles to the Crown Point Iron Works to see the machine with his own eyes. Still unsatisfied, he traveled more than three times that distance hoping to meet the machine’s inventor, but by the time he reached Albany, New York, Henry had relocated to teach at Princeton University in New Jersey. Determined, Davenport returned to his home briefly before heading back to Crown Point. There he and his brother traded his horse and sold a number of other possessions to raise funds to buy a Henry electromagnet.
Once he got the magnet home, Davenport set about learning how it was made. He deconstructed the device while his wife wrote down his findings. Davenport used the information to build his own electromagnets, with which he soon began to carry out experiments. To provide insulation for the wire windings of the new magnets, Mrs. Davenport sacrificed the silk from her wedding dress. A Volta-type battery provided the electricity. While experimenting in 1834, Thomas Davenport developed what we today know as a DC motor, complete with a brush and commutator. Realizing the potential of his invention, Davenport used it to power a small model of a train and some of the machines in his workshop.
Davenport wanted to patent his motor, but initially the U.S. Patent Office denied his application. No one had ever been granted a patent for an electric device before, and the government office did not make it easy for him. He decided to try again after collecting letters of recommendation from professors and scientists who saw his motor demonstrations. This time, a fire at the office destroyed his application, the letters and the model he submitted. It was not until February 25, 1837, when Davenport finally received his long sought-after patent.
Even with the patent Davenport was unable to make much money with his motor. He had trouble in the partnerships he formed, and the expense and erratic electricity supplied by the batteries then available meant that motors were less practical than the tried-and- true steam engine. Financially ruined, Davenport eventually left the laboratory he had set up in New York to return to Vermont with a plan for writing a book about his vision for the electric motor. He died before the book was completed and without ever really knowing what an impact his work would one day have on people around the world.
