Michael Faraday was a firm believer that solid experimentation was needed in order for a theory to be supported. Whilst experimenting with electrical currents in 1819, he discovered that when a current passed through wire, it deflected the directional needle of a compass. This was the first time magnetism had been linked to electricity. From these observations, Faraday came to conclusion that electricity created some sort of magnetic field. After much deliberation he decided that the converse must be true as well, that magnetism creates electricity. This theory however, took him nine years to prove.
Faraday continued his experimentations with electromagnetism. He found that he could make and iron nail into a magnet by placing it inside a coil of wire with current running through it. This was the first electromagnet to be invented.
It was not until the 29th of August 1831 when he discovered electro-magnetic induction. This was the principle behind the electric transformer and generator.
He created a circuit using a soft iron core ring linked through two detached coils of wire. One coil of wire was attached to a Galvanometer , and the coil formed an open circuit that connected to a power source. When the circuit was shut off a momentary current was induced in the secondary coil. When the circuit was reopened the same results occurred. Faraday removed the iron ring, and discovered by accident that when the circuit is closed, and the two separated coils are close to each other, the magnetism which formed in the coil connected to the power source will induce magnetism in the nearby coil for a moment (see Diagram 7). When the circuit was reopened these very same results occurred. This experiment displayed that one object affected another object with no use of any mechanical component.