In school, Thomson showed a keen interest in the classics along with his natural interest in the sciences.
At the age of 12 he won a prize for translating Lucian of Samosata's Dialogues of the Gods from Latin to English.
William Thomson's father, James Thomson, was a teacher of mathematics and engineering at Royal Belfast Academical Institution and the son of a farmer.
James Thomson married Margaret Gardner in 1817 and, of their children, four boys and two girls survived infancy.
William and his elder brother James were tutored at home by their father while the younger boys were tutored by their elder sisters.
The title refers to the River Kelvin, which flows close by his laboratory at the University of Glasgow.
His home was the imposing red sandstone mansion Netherhall, in Largs.
On gaining the fellowship, he spent some time in the laboratory of the celebrated Henri Victor Regnault, at Paris; but in 1846 he was appointed to the chair of natural philosophy in the University of Glasgow.
At twenty-two he found himself wearing the gown of a learned professor in one of the oldest Universities in the country, and lecturing to the class of which he was a first year student but a few years before.