Electricity was not invented by mankind, it couldn't have been as it can occur naturally under the right conditions with no help from people, lightning is a perfect example of this. What man had to do to harness this energy was to understand it, how it is created, what are its properties and limitations and then discover how to make it work in his service. This page aims to tell the story of who carried out the early experiments and what did our understanding of this powerful force gain from their work.
Alessandro Volta (1745-1827) was an Italian physicist (at the University of Pavia) who invented the chemical battery (also called the voltaic pile) in 1800. This invention provided the first generator of continuous electrical current. Constructed of alternating discs of zinc and copper, with pieces of cardboard (some say he used cloth) soaked in brine between the metals, the voltaic pile produced electrical current. You may well ask that if there were no bulbs, motors or devices for measuring electricity then how did he know it worked? Simply by brushing wires from each terminal together and producing sparks, this was proof to Volta of the presence of an electrical charge.
Volta had carried out much pioneering work prior to this in the field of static electricity and also carried out research into atmospheric electricity but it is for his creation of the voltaic pile that he is eternally remembered. The 'volt'; the name for the standard measurement for electrical charge as we hear today, was named after Alessandro Volta (pictured left) in 1881 in honor and memory of him.
Hans Christian Ørsted (1777-1851) was born to Danish parent but raised in Germany. He made the important discovery that an electrical current had magnetic properties depending on the direction it flowed in a circuit. He did this by deflecting a compass needle with a charged loop of wire, thus was the electro magnetic field discovered. His work work picked up on by one André Marie Ampère (1775 - 1836) who published his own theories on electricity and magnetism in 1826. The Amp, the universal unit of measuring electrical current is named in honor of Ampère.
Georg Simon Ohm (1787-1854) from Erlangen, Germany, was able to define the relationship between voltage, current, and resistance. What is now known as Ohm's law appeared in his most famous work, a book published in 1827 that gave his complete theory of electricity. These fundamental relationships are of such great importance, that they represent the true beginning of electrical circuit analysis. Ohm was afraid that the purely experimental basis of his work would undermine the importance of his discovery. He tried to state his law theoretically but his rambling mathematically proofs made him an object of ridicule. In the years that followed, Ohm lived in poverty, tutoring privately in Berlin. He would receive no credit for his findings until he was made director of the Polytechnic School of Nüremberg in 1833. In 1841, the Royal Society in London recognized the significance of his discovery and awarded him the Copley medal. The following year, they admitted him as a member. In 1849, just 5 years before his death, Ohm’s lifelong dream was realized when he was given a professorship of Experimental Physics at the University of Munich.
The equation I = V/R is known as "Ohm’s Law". It states that the amount of steady current through a material is directly proportional to the voltage across the material divided by the electrical resistance of the material. The ohm (R), a unit of electrical resistance, is equal to that of a conductor in which a current (I) of one ampere is produced by a potential of one volt (V) across its terminals.
Michael Faraday (1791-1867) was a Londoner who also experimented with the magnetic properties of electricity, in 1821 he built two devices to produce what he called electromagnetic rotation: that is a continuous circular motion from the circular magnetic force around a wire and the basis for all electric motors. Ten years later, in 1831, he began his great series of experiments for which he built a device known as an "induction ring". Faraday (pictured left) now made one of his greatest discoveries - electromagnetic induction: the "induction" or generation of electricity in a wire by means of the electromagnetic effect of a current in another wire. The induction ring was the first electric transformer. In a second series of experiments in September he discovered magneto-electric induction: the production of a steady electric current. To do this, Faraday attached two wires through a sliding contact to a copper disc. By rotating the disc between the poles of a horseshoe magnet he obtained a continuous direct current. This was the first generator. From his experiments came devices that led to the modern electric motor, generator and transformer.
Whilst there were others who experimented in the field of electricity in the first half of the 19th Century and had published works meet with acclaim it is recognised that the work of those named above gave us the basic means by which we understand the ways of producing electricity, how it behaves and how it can be employed.
