The unit for energy is name after James Prescott Joule (1818-1889).
Joule worked at the family brewing and his interest in science started as he was trying to work out if a steam engine or an electrical motor would provide the most power for his brewery. He worked out the steam engine would be most cost efficient. This work stimulated a greater interest in science and so he devised further experiments into the link between heat and mechanical work.
He showed that energy from mechanical work was converted into heat. At the time his work was widely ignored. Most scientists doubted his ability to measure the small changes in temperature required. However they had failed to recognise his background in brewing, which required Joule to be able to measure temperatures accurately.
He received the Royal Medal from the Royal Society in 1852 for his paper onthe mechanical equivalent of heat.
His work would also provide evidence for kinetic theory and the first law of thermodynamics.