Lord Kelvin (William Thomson) was one of the founders of modern physics, probably the greatest applied scientist of the Victorian era.

Thomson's father was a farm labourer who became a Professor of Mathematics at Belfast and from 1832 at Glasgow. William Thomson studied science in Glasgow University from age 10, and had worked in both Cambridge and Paris before becoming a Professor of Natural Philosophy at Glasgow for 53 years. . He was offered, and declined, the Cavendish Chair at Cambridge three times, but instead persuaded all the major scientists of the time to come to Glasgow.

Kelvin had an excellent grasp of all aspects of physics: heat, light, sound, electricity. In his early days he performed experiments in electric lighting, thermodynamics and electrodynamics. He studied radioactivity, and encouraged the Curies in their experiments with radium.

He was a very talented scientific instrument designer, and later became associated with James White's company (founded in 1849), when he realised many of the instruments he was devising in the laboratory could be adapted for manufacture. Early on, they made rangefinders for Professors Barr and Stroud (who had formed a company, Barr and Stroud, in response to an advert for an efficient rangefinder placed by the War Office in 1888).

It was Kelvin's involvement in submarine telegraphy, and the laying of the first transatlantic telegraph cable in 1866, which made him internationally famous however, as well as his redesigned nautical compass and sounding equipment. Thomson also did much work in the field of thermodynamics (Heat) - he proposed in 1848 an absolute scale of temperature now known as the Kelvin scale: 0oC = 273.16K.

Thomson worked on the theory of the cooling of a hot solid sphere and applied this theory to calculate ages for the Earth and the Sun. His results were about 10 times lower than present values which now take into account heat due to radioactivity,  which was not discovered until many years after Thomson's early work. Thomson wrote 661 papers, many books and patents and was probably the first scientist to become wealthy through science.

He had his own steam yacht (the Lalla Rookh), on which he held many social events as well as a number of scientific inquiries.

In 1892 he was made a Baron. Lord Kelvin died in 1907, aged 83, and is buried in Westminster Abbey, London.