Joule set up a laboratory in the cellar of the family home. He began a series of experiments on the nature of energy and published the findings that became known as Joule's first law in 1840.

Horseshoe-shaped electromagnet used by James Joule, c.1840. This electromagnet was used by the scientist James Joule for experiments about energy. Joule was a Salford resident and the son of a brewer.

Joule set up a laboratory in the cellar of the family home. He began a series of experiments on the nature of energy and published the findings that became known as Joule's first law in 1840.