William Sturgeon and the Invention of the Electromagnet

Early electromagnet experiment. Oxford Science Archive/Print Collector/Getty Images

An electromagnet is a device in which a magnetic field is produced by an electric current. 

British electrical engineer William Sturgeon, a former soldier who began to dabble in the sciences at the age 37, invented the electromagnet in 1825. Sturgeon’s device came a mere five years after a Danish scientist discovered that electricity emitted magnetic waves. Sturgeon harnessed this idea, and conclusively demonstrated that the stronger the electric current, the stronger the magnetic force.

 

The first electromagnet he built was a horseshoe-shaped piece of iron that was wrapped with a loosely wound coil of several turns. When a current was passed through the coil the electromagnet became magnetized, and when the current was stopped, the coil was de-magnetized. Sturgeon displayed its power by lifting nine pounds with a seven-ounce piece of iron wrapped with wires through which the current of a single cell battery was sent. 

Sturgeon could regulate his electromagnet—that is, the magnetic field could be adjusted by adjusting the electrical current. This was the beginning of using electrical energy for making useful and controllable machines and laid the foundations for large-scale electronic communications. 

Five year later an American inventor named Joseph Henry (1797-1878) made a far more powerful version of the electromagnet. Henry demonstrated the potential of Sturgeon's device for long distance communication by sending an electronic current over one mile of wire to activate an electromagnet which caused a bell to strike.

Thus the electric telegraph was born. 

After his breakthrough, William Sturgeon taught, lectured, wrote and continued experimenting. By 1832, he had built an electric motor and invented the commutator, an integral part of most modern electric motors, that allows the current to be reversed to help create torque.

In 1836 he founded the journal “Annals of Electricity,” kicked off the Electrical Society of London, and invented a suspended coil galvanometer to detect electrical currents. 

He moved to Manchester in 1840 to work at the Victoria Gallery of Practical Science. That project failed four years later, and from then on, he made his living lecturing and giving demonstrations. For a man who gave science so much, he apparently earned little in return. In poor health and with little money, he spent his last days in dire circumstances. He died on 4 December 1850 in Manchester.