200 years later - in celebration of Faraday’s Electric Motor

The scientific discoveries of self-taught scientist Michael Faraday, made in his basement laboratory at the Royal Institution, shaped the world, changed our understanding of the laws of physics, and remain vital to our modern technological world.

None more so than development of the world’s first electric motor, over 200 years ago this year, in September 1821.

Faraday’s electric motor represents an early outcome of his life’s work investigating electro-magnetism. It was the first time it was possible to make electricity practical and widely-used and was the foundation of Faraday’s subsequent development of the dynamo or electric generator.

Electric power, mass communication, motorised travel, computers, mobile phones – none of these would be possible today without Faraday’s two-centuries old invention. 

Why the electric motor was so important

It was the first time it was possible to make electricity practical and paved the way for its widespread use around the word. 

The motor was an early outcome of Faraday’s life’s work experimenting with electro-magnetism. Having generated continuous mechanical motion from magnetism and electricity (the electric motor), he then began work to generate electricity from mechanical motion and magnetism (the electric dynamo, or generator). This was a discovery that would transform our world, ultimately powering a ‘second industrial revolution’, and making possible other life-changing inventions such as the lightbulb.

The motor as conceived by Faraday is still central to our modern technological world.

There are motors in everything from laptops to electric guitars to satellites. The electric power we use around the world relies on generators, another of Faraday’s inventions, that stem directly from his motor. If you look around your home – in the kitchen alone you have washing machines, dishwashers, microwaves, blenders, etc all of which rely on motors – you will always find something that is still built on Faraday’s work. 

It led directly to Field theory, considered to be one of the most astonishing theories, eclipsed only by Einstein’s Theory of Relativity.

When developing the motor, Faraday came up with the concept of lines of force, which was mathematised by James Clerk Maxwell. Maxwell’s work laid the foundations for radio waves and our understanding of modern physics, including Einstein’s work on special relativity and the development of quantum theory.

Why is Michael Faraday so important?

Albert Einstein kept a picture of Faraday on his study wall. Physicist Ernest Rutherford, known as the father of nuclear physics, said: "When we consider the magnitude and extent of his discoveries and their influence on the progress of science and of industry, there is no honour too great to pay to the memory of Faraday, one of the greatest scientific discoverers of all time.”

Faraday is regularly included in any assessment of the most influential scientists of all time.

As well as the electric motor and generator, he also  

• Isolated the chemical element benzene, a major component of petrol, for the first time
• Discovered diamagnetism, when materials are repelled by a magnetic force and the laws of electrolysis
• Invented the Faraday Cage, which among its uses today is the protection of important electrical components, e.g. in aircraft operating systems, from interference
• First used terms such as anode, cathode, electrode and ion

He exemplified that science is for everyone.

Faraday had relatively little formal education and was employed as a book binder when he first began to attend Humphry Davy’s lectures at the Royal Institution, learning by reading the books he was binding. His scientific knowledge and skills were self-taught, yet he became the greatest scientists of his generation, demonstrating that everyone can make their mark in science, regardless of their background.

He campaigned for education.

Although Faraday himself had little formal education, he took it upon himself to educate the general public about science. Humble and unassuming, he turned down the Presidency of the Royal Society and would never accept a knighthood. And at a time when there was little formal education for children, in 1825 Faraday instigated the now world-famous Royal Institution Christmas Lectures, today broadcast every year on the BBC.

He campaigned against pseudoscience

As relevant today as it was then, Faraday was concerned at society’s fascination with trickery, notably in the form of spiritualism. In a famous demonstration at the Ri, Faraday proved to a public audience that ‘table-turning’ during a séance was not due to spirit activity, but rather the inadvertent pressure of the participants’ own hands. 

How the motor came about

In 1820 Hans Christian Ørsted announced his discovery that the flow of an electric current through a wire produced a magnetic field around the wire. André-Marie Ampère followed on and showed that the magnetic force apparently was a circular one, producing in effect a cylinder of magnetism around the wire. No such circular force had ever before been observed. 

Self-taught British scientist Michael Faraday (1791 – 1867) was the first to understand what these discoveries implied. If a magnetic pole could be isolated, it ought to move constantly in a circle around a current-carrying wire. In 1821 Faraday set about trying to understand the work of Ørsted and Ampère, devising his own experiment using a small mercury bath. This device, which transformed electrical energy into mechanical energy, was the first electric motor.

How it worked

The motor features a stiff wire which hangs down into a glass vessel which has a bar magnet secured at the bottom.  The glass vessel would then be part filled with mercury (a metal that is liquid at room temperature and an excellent conductor). Faraday connected his apparatus to a battery, which sent electricity through the wire creating a magnetic field around it. This field interacted with the field around the magnet and caused the wire to rotate clockwise.

Further reading (if needed): 

The Ri website

Jim Al-Khalili’s summary of Faraday’s work, including the motor, written for the Royal Society

Wikipedia