How did Michael Faraday discover electromagnetic induction in 1831?

In 1831, Michael Faraday discovered electromagnetic induction through a series of experiments inspired by his interest in how dynamic forces create effects in nearby objects.1

On August 29, 1831, Faraday conducted his most famous experiment using an iron ring wound with two separate coils of wire. He connected one coil to a battery and the other to a galvanometer. He observed that closing or opening the primary circuit caused the galvanometer needle to jump, indicating that a current was induced in the secondary coil during the moments the magnetic field was changing.1

Later that year, Faraday expanded his research by using a permanent magnet. He discovered that moving a magnet into and out of a coil of wire induced a current, as did moving a conductor near a stationary magnet. He concluded that the magnitude of the induced current depended on the number of "lines of force" cut by the conductor per unit of time. This work led him to invent the dynamo, the first device to produce a continuous electric current from a magnetic field.21