Two Faradays and two electromagnetic discoveries
Michael Faraday is one of the most well known names in science, probably even for people outside science. He made two landmark discoveries which led to the invention of the electric motor and the electric generator — two devices which we benefit from, every single day of our lives. But equally legendary is Faraday’s fairytale journey from being a bookbinder’s apprentice to the assistant of Britain’s biggest scientist of the time, Humphry Davy.
The relationship of Faraday and Davy — master and servant, professor and student, and eventually and inevitably rivals — is a fascinating story in itself. A story that reveals a lot about not just the two individuals but also the quirks of English society at the time.
The two discoveries in electromagnetism referred to above were not made together. In fact, they were separated by a decade. And they were made by two different Faradays. The first by a 30-year old lab assistant with his head brimming with ideas and craving for an intellectual outlet; the second by a 40-year old established scientist, elected to the Royal Society and successor to the illustrious position previously occupied by his mentor.
It is the first discovery that is the subject of this article.
In the summer of 1820, Danish scientist H. C. Oersted had discovered that a magnetic compass needle is deflected when kept near a current-carrying wire. News of this momentous discovery soon reached all parts of Europe, and it reached Humphry Davy too. Faraday got the opportunity to learn about the phenomenon assisting Davy in his recreation of Oersted’s experiment, and it captivated him.
By now, Faraday had been in the service of Davy and the Royal Institution for over eight years. From the very first days, Davy had recognised the brilliance of Faraday’s intellect. As Faraday assisted Davy in the laboratory, the two would engage in conversations that played a big part in Faraday growing into a scientist in his own right.
The deflection of the magnetic needle was a hot topic of discussion that year. Faraday had probably been a spectator if not a participant in the conversations Davy had with his friend William Hyde Wollaston on the subject. Wollaston thought that it must be possible to somehow produce continuous motion using magnets and electric currents, but had failed in his attempts.
After his work hours, Faraday played with wires and batteries and magnets. One day, he put together a strange apparatus. He fixed a long magnet in the middle of a cup and filled the rest of the cup with mercury. Above the magnet and the cup was a support from which a piece of wire was hanging freely, with one end dipped in the mercury.
Faraday connected one terminal of a battery to the hanging wire through its support, and the other terminal to the mercury in the cup. The moment the circuit was completed, the hanging wire began going around the magnet, in circumambulation. Faraday had got what he was looking for — continuous electromagnetic rotations!
Announcement and indignation
This should have been the moment when Faraday became a celebrated scientist, but it wasn’t.
Faraday excitedly called on Wollaston to tell him about the electromagnetic rotations, but Wollaston was out of town. Faraday knew that he had discovered something extremely important, and couldn’t wait to communicate it to the world. He wrote a 16-page article titled “On Some New Electro-Magnetical Motions” and naively sent it to the Quarterly Journal of Science for publication.
Within days, all hell broke loose. Members of the scientific community accused Faraday of stealing Wollaston’s ideas while the latter was still working on them. Faraday was also condemned for not acknowledging the knowledge he gained by assisting Davy in his experiments.
Davy did not overtly criticise Faraday. However, his silence when he could have doused the raging controversy suggests that he felt the criticism was deserved. Wollaston himself was graceful, and invited Faraday to come and discuss his new experiments. Wollaston must have realised that his own ideas were somewhat different from Faraday’s electromagnetic rotations.
Into an exile from electromagnetism
Faraday received the support of scientists in continental Europe, and he quickly grew in stature. However, in London, he was still Davy’s servant.
Over the next few months and years, Davy kept Faraday busy with many non-scientific tasks. Even in science, Davy assigned work in other areas of research that made sure there wasn’t much time for Faraday to build on his work in electromagnetism. Faraday’s diary entries of the 1820s reveal that he hardly did any electromagnetic experiments for the rest of the decade.
Still, Davy couldn’t stop the emergence of Faraday as a scientist. In 1823, Faraday’s name came up for election as a Fellow of the Royal Society. Davy staunchly opposed the nomination, and for the first time publicly condemned Faraday for his indiscretion of a couple of years earlier. Faraday, however, had the support of a majority of the members including Wollaston, who clearly did not hold any grudge against him.
Nevertheless, it was only after the death of Davy in 1829 that Faraday could truly get back to the work that he was destined to do. This time, in 1831, Faraday would go on to discover how electric currents could be produced by the motion of a magnet and a wire. Even today, most of our electrical energy is produced using this principle uncovered by him.