In the early 19th century, much of what we now take for granted in engineering was unknown or even mistaken for magic. One of the first secular wizards to build much of the foundation of what we now call electrical science and engineering was Michael Faraday.
A portrait of Michael Faraday created in the 1820s.
Michael Faraday was born in 1791 in England. The son of a blacksmith, Faraday was not easily ushered into the world of academia. As a child, he apprenticed under a bookbinder, giving him ample opportunity to read. His inquisitive mind led him to attend lectures at the Royal Society, among them a lecture by chemist Humphry Davy. Faraday sent Davy over 300 pages of notes he'd taken on this series of lectures, the diligence of which prompted Davy to hire Faraday on as his assistant. Through Davy, Faraday was able to meet and learn from many of the great scientific minds of Europe.
Faraday never received a fully formal education, though he did receive an honorary Doctor of Civil Law degree from the University of Oxford at the age of 41. Despite this and despite his birth to a common family—a rarity among intellectual circles of the day—Faraday came to achieve fame and veneration in his field.
Throughout his life, Faraday was responsible for several greatly important discoveries in the field of electromagnetism. Here's an overview of some of his most notable contributions to science and engineering.
The World’s First Electric Motor
Before Faraday, Hans Christian Ørsted had already demonstrated the link between electricity and magnetism, heretofore unknown. The apparatus was simple: an electric battery and a wire loop placed in proximity to a compass needle. When the battery’s voltage was applied to the wire, the compass needle moved.
Faraday took the idea one giant step forward, by demonstrating the first electric motor.
Left: A rendering of Faraday's electric motor (modified). Image courtesy of Konstantin Weise via Research Gate. Right: A photo of an actual Faraday's electric motor. Image used courtesy of Paul Wilkinson via the Royal Institute, London.
Looking at the schematic to the left, note that a permanent magnet is mounted within a pool of mercury and that the battery’s positive terminal is connected to the pool of mercury. A hook loosely suspends one end of a wire and the other end of that wire dips into the mercury.
Mercury is, of course, a liquid so the wire is free to move and, because mercury is also a conductor, once the battery is connected there is a closed circuit. As we now know, an electrical current flowing through a conductor creates its own magnetic field, which here interacts with the magnetic field provided by the permanent magnet, causing circular motion.
The result is that the suspended wire rotates around the battery. While the invention had few immediate, practical results, the astonishing potential of the discovery was obvious to all.
The picture below is the world’s first electrical transformer, created by Faraday in 1831.
Faraday’s induction ring. Image used courtesy of Paul Wilkinson via the Royal Society
What we have here are two electrically independent coils wound upon a metal core. When a current was induced in the first coil, an electrical signal appeared across the second. Most importantly, the signal on the second coil was only present at the moment the first current was applied and at the instant the current was removed.
Faraday also discovered that inserting a magnet into a coil of wire would also “induce” a current in that wire. Similar to the previous experiment, however, the induced current only appeared during times that the magnet was moving, i.e., when the magnetic field presented to the coil by the magnet was changing.
Thus was discovered magnetic induction, whereby a changing magnetic field presented across an electrical conductor produces electricity.
The First Electrical Generator
Faraday also devised what can be considered the first electrical generator. Again, it is most easily understood when comparing a version constructed today to Faraday's own illustrations.
Left: A modern-created version of Faraday's electric generator. Image used courtesy of Skulls in the Stars. Right: A rendering of Faraday's original electric generator drawn by Faraday in 1884
Looking at the model on the left, the black items are permanent magnets. Turning the crank rotates the copper disk. This generates an electric potential measured from between the center of the disk and its outer edge.
Advances in Chemistry
While Faraday is most noted for his contributions to the then-nascent field of electroscience, he also made some important contributions to chemistry. Perhaps most notably, while not the discoverer of electrolysis, he did formulate quantitative relationships describing the process in terms of the amount of current applied over time.
He was also the first individual to isolate benzene and discovered that the compound contained equal numbers of carbon and hydrogen atoms. He was also the first researcher to synthesize compounds derived from carbon and chlorine, C2Cl6 and C2Cl4.
Among the many ways that this groundbreaking physicist, chemist, and inventor is immortalized is his namesake, the farad, the definition of the storage capacity of a capacitor.
Faraday died in 1867 at the age of 75. He is buried with his wife Sarah in London, having turned down a place of burial in Westminster Abbey.
How have Faraday's accomplishments affected you? Which engineer would you like to see discussed next? Share your thoughts in the comments below.