LECTURE

KELVIN BY DEGREES: UNDERSTANDING THE LIFE AND WORK OF WILLIAM THOMSON, LORD KELVIN

Professor Crosbie Smith, Centre for the History of Science, University of Kent at Canterbury; Editor of the British Journal for the History of Science, on 25 November, 1999

Joint Lecture with the Institute of Physics

Although Fourier, Maxwell and Kelvin secured 19th century fame, Kelvin was later thought outmoded or wrong. Moreover, most of his work was practical rather than theoretical and the bulk of his written work deterred historians until Kuhn's concentration on the actual practices of scientists renewed investigative activity in the 1960s. William Thomson's father was a professor at Belfast Academical Institution, then a mathematics professor at Glasgow University from 1832 to 1849, when he died. William went to Cambridge at 20, secured a Second in the Maths Tripos in 1845 and took the Chair of Natural Philosophy (Physics) at Glasgow University in 1846, at the age of 22. He held that post until 1899, latterly becoming Lord Kelvin.

With illustrations of venues involved, Professor Smith then discussed William's reforms of the University, his Department and physics itself. In the early 19th century Glasgow prospered and expanded to over 250,000 citizens and its commercial leaders favoured Whig policies in support of applied science under free enterprise, exemplified by James Watt and Adam Smith earlier. The academic prestige of the University, which was founded in the 15th century, was by then very low. Entry was open to anyone with money, regulations were lax and appointments were restricted to a Tory elite. William's 1846 appointment began staffing reforms and recognition of the significance of practical sciences both by wealthy Glaswegians and by Disraeli's government, who jointly provided £350,000 to demolish the medieval buildings and build afresh on a new site in 1870.

Upon his appointment William replaced outdated equipment, but took care to spend wisely, thus securing more support. He supplemented his own constructions with local crafts devices and Parisian instruments. He first instituted demonstrations then laboratory research. By the 1860s he was using most of the old college buildings for experimentation and he was designing, marketing, manufacturing and patenting scientific instruments. He used Brunel's `Great Eastern' to lay telegraph cable between Ireland and Canada, later cabling to India and the Empire. He prompted a re-sited and expanded Glasgow University and was awarded a knighthood. He sought reform of British electrical engineering and patented an improved mariners' compass, which was then used in merchant shipping up to 1914.

In the early 19th century Paris led the world in science and medicine; Laplace then explained natural phenomena through universal laws, and young British academics favoured continental mathematics. However, after the British Association was established in 1831 studies central to a developing empire developed, covering tides, terrestrial magnetism, meteorology, etc. Fourier's concern for observation and experiment replaced Laplacean microscopic force theories as a basis for mathematical physics. Thomson, Faraday and Maxwell developed `field' theory. William, after consulting his engineer brother James, studied waterfalls and steam engines. After correlating temperature differences with work done, he produced an absolute temperature scale independent of involved substances. Energy became defined as capacity for doing work and work as a measure of natural thermal, electrical or mechanical energy. He then produced laws of energy conservation and dissipation, recognising energy transfer to heat. After 1850 terms such as `kinetic energy' and `thermodynamics' were employed in physics.

When English scientists theorised an age for the Earth which was much too brief for evolution to have operated, Thomson and others tackled the problem through physical studies. His attempts to render physics comprehensible and useful to artisans included a book on dynamics in 1867 and continuing promotion of absolute units which would relate measurement to a concept of `work'. He died in 1907 at the age of 83, and was buried in Westminster Abbey.

Geoff Catchpole