James Prescott Joule
Early/personal Life
James Prescott Joule was born on December 24, 1818 In Slaford, England. He was born into a wealthy brewing family with an older brother named Benjamin and three other siblings. James was a very shy and weak child, who had spinal disorder. His spinal disorder greatly affected his life. He could not participate in any physical activity. James Joule was homeschooled, but also had a tutor named John Dalton. “It was from his instruction that I first formed a desire to increase my knowledge by original researches,” James joule said about John Dalton James and his brother also studied at the Manchester library. Sadly after two years of John tutoring him, he was forced to retire after he had had a stroke. Later he got a new tutor also named John. Together they experimented with electricity. He was homeschooled till he turned 15, then he went to work at the brewery. When his father got sick he and his older brother took over the brewery. Later in life he got the desire to be a scientist and left the brewery. James Presscot joule died of old age sadly on October 11, 1889
James joule Experimented with heat and electricity and how heat produces energy. He studied many different types of heat and their electrical currents. He had a laboratory near his father’s brewery, but then moved the lab to a better location in his basement. James also worked with Lord Kelvin, a famous scientist in physics, on many of his projects. Although he was working as a scientist, he was also a part time brewer at his father’s successful brewery. James sent in a paper entitled “On the Production of Heat by Voltaic Electricity” To the Royal Society in London. The Royal Society was probably one of the most prestigious science schools in all of England. In the paper he explained that a wire carrying an electrical current equals a current I squared by the resistants. In 1847 a man named William Thompson (better known as lord kelvin) recognized his work and respected it. Later Kelvin told Joule that he has good work and they conducted many experiments together.
These are the major discoveries that James Joule is known for:

  • “Law of conservation and energy” Energy cannot be created or destroyed. The sum of all energy in a system is a constant.
  • “First law of Thermodynamics” it states that internal energy, heat, and working energy are conserved.
  • “Joule unit of Measure” Work or energy in the international system of units (S1) is equal to the work done by a force of one newton acting through one meter.
  • He made observations of magnetostriction in 1842. It causes a material to change their shape or dimension due to the process of magnetization.
  • He discovered the mechanical equivalent of heat = 772.55
  • Joules first law describes the rate at which resistance in a circuit converts. Electric energy into heat energy.
  • He found that the amount of heat per second produced in a wire with a current is proportional to the electrical resistance of the wire and the square of the current
Awards and honors
Joule sent in a paper to the royal society about voltaic electricity and they thought his work was decent so they published a small paper about it.
  • Fellow of the Royal Society (1850)
  • Received the Copley medal (1870)
  • Received the Royal Medal (1852)
  • Became the President of Manchester Literary and Philosophical Society (1860)
  • Become president of the British Association for the Advancement of Science (1872, 1887)
  • Honorary membership of the Institution of Engineers and Shipbuilders in Scotland (1857)
  • Received honorary degrees from Trinity College in Dublin (1857), University of Oxford (1860), and University of Edinburgh (1871)
  • Received the Albert medal of the Royal Society of Arts (1880)

Fun facts
  • The Fahrenheit and Celsius scale that scientist use is called the Kelvin scale, after the scientist Lord Kelvin who James had worked with.
  • A famous scientist named John Dalton tutored him.
  • The unit of measurement the “Joule” was named after James Prescott Joule.
  • 772.55 is engraved on his tombstone.


Citation 5:



Balchin, Jon. Science, 100 essential scientists. New York: Enchanted Lion, 2005 print.

citation 3

Balchin, Jon. 100 scientists who changed the world. Enchanted lion books, October 1st 2003

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citation 5:


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