The mathematician and physicist William Thomson, 1st Baron Kelvin, (1824-1907) was one of Britain’s most influential scientists, famous for his work on the first and second laws of thermodynamics and for devising the Kelvin scale of absolute temperature. Silvanus P. Thompson (1851-1916) began this biography with the co-operation of Kelvin in 1906, but the project was interrupted by Kelvin’s death the following year. Thompson, himself a respected physics lecturer and scientific writer, decided that a more comprehensive biography would be needed and spent several years reading through Kelvin’s papers in order to complete these two volumes, published in 1910. Volume 1 covers Kelvin’s life to 1871, including his student days, his election (aged 22) as professor in Glasgow, his ground-breaking theoretical research on thermodynamics, his applied work on telegraphs including the Atlantic cable, and his involvement in a geological controversy about the age of the earth.