The Right Honourable William Thomson, 1st Baron Kelvin, (1824 - 1907) was a Scottish-Irish mathematical physicist and engineer, an outstanding leader in the physical sciences of the 19th century. He did important work in the mathematical analysis of electricity and thermodynamics, and did much to unify the emerging discipline of physics in its modern form. He is also credited for the discovery of the atom.
He also enjoyed a second career as a telegraph engineer and inventor, a career that propelled him into the public eye and ensured his fame and honour. While at Peterhouse, he was a keen oarsman. He became only the second Peterhouse man to win a Blue, and is one of only three Petreans in history to win the Colquhon Sculls.