Count Rumford
Count Rumford, or Sir Benjamin Thompson, was an American born physicist and inventor who made large contributions to the field of thermodynamics. Rumford was born in pre-revolutionary America and was opposed to the revolution. He was active in recruiting loyalists and spying for the British forces. During his time in the war he took an interest in cannons, and conducted experiments to measure the force of gunpowder. Once the war was over, Rumford was forced out of the states and took up a job as an adviser to the Prince-elector of Bavaria. There he studied many methods of cooking and invented a soup designed for the poor. This is also when he began his extensive experiments on heat, with his main goal being to disprove Caloric Theory. Caloric theory stated that heat was a fluid called caloric that flows from hot objects to cold objects. This theory was widely accepted at the time because it was theorized by Antoine Lavoisier, a giant in the field of chemistry and physics. Rumford sought to disprove it by using a blunt boring tool to create friction which then heated water. He proved that the friction was the cause of the heat and that there is seemingly indefinite heat that can be generated. Though the work was not given much worth at the time, his discovery was a key connection between motion and heat and was helpful in establishing the laws of conservation of energy. Rumford was an active inventor and made improvements to chimneys, fireplaces, and industrial chimneys. He invented a double boiler, a kitchen range, and a drip coffeepot. Rumford was quite the star during his time and was a member of the American Academy of Arts and Sciences, the Royal Swedish Academy of Sciences, and had a professorship at Harvard University. Rumford also married the widow of the French chemist Antoine Lavoisier (yes the same Antoine Lavoisier who invented caloric theory) but the marriage did not last long and they seperated after a year.
https://en.wikipedia.org/wiki/Benjamin_Thompson