There's no measure of the man without idea of his age

Towards the end of this book, David Lindley writes: "I have tried to tell Kelvin's story as the saga of a man equipped with a particular set of talents and a particular cast of mind. Where these things came from I don't pretend to know." In his own words, Lindley neatly summarises the historical poverty of his text and the problems of attempting to write biography out of context.

Writing biographies must seem a tempting way of producing a book quite quickly because, it could be argued, that one needs to study only the subject's writings and papers. The problem is that without a firm grasp of the historical context in which an individual lived, it becomes impossible to understand how and why a person acted as he or she did. Hence the admission by Lindley, an astrophysicist by background, that he does not understand what made Kelvin tick - a statement that does not inspire confidence in this biography of him.

William Thomson (1824-1907, Lord Kelvin from 1892) was born in Belfast and studied at Glasgow, Cambridge and Paris before being appointed professor of natural philosophy at Glasgow University in 1846 at the age of 22, a position that he held until 1899. The scientific work that made his name included placing Michael Faraday's electromagnetic field theory on a firm mathematical basis and developing the first two laws of thermodynamics, a word he coined.

Lindley does not even begin to appreciate the deeply theistic approach to thermodynamics that Thomson pursued. In general, he relegates Thomson's religious beliefs to little more than conforming to social norms. However, the manuscript draft of Thomson's paper on the second law contains biblical quotations in the footnotes. Once the second law had been established, it had the immediate consequence of posing the problem of the source of solar energy. For Thomson and others, this had obvious resonance with the history and future of the universe as outlined in the Bible. Thomson's research path culminated with his developing the idea of the heat death of the universe, maintaining (by modern standards) a comparatively short age of the earth and rejecting throughout his career Darwin's theory of evolution by natural selection. At one level, Lindley realises that Thomson held all these views, but in his metaphorical effort to award marks out ten to Thomson for his work, he seeks to explain the views away in terms of an old man maintaining the mistaken views of his youth rather than understanding that they came from Thomson's consistent theological view of the world.

It seems to me that the main problem with Lindley's approach to Thomson stems from the fact that he does not understand how the practice of modern science is different from that of the 19th century. It is not just in the theological arena that there are problems. After the main bulk of his creative work in the 1840s and 1850s, Thomson became involved in a number of practical problems that required scientific method and knowledge. The most important of these were the Atlantic telegraph cables of the 1850s and 1860s and developing a marine compass for iron vessels from the 1870s onwards. Lindley is puzzled why someone of Thomson's creative calibre should become involved in developing such practical technologies, seemingly unaware that there was a long tradition of this that continues to this day.

Furthermore, he takes an old-fashioned view of the Admiralty's policy towards new technical development when recent research has shown how innovatory it was in, for example, supporting Guglielmo Marconi's work on wireless telegraphy.

By way of conclusion, I would like to ask what readers expect to gain from biographies such as this. There have been quite a few published in recent years, starting with Dava Sobel's on John Harrison. Generally they are written by people who have little or no expertise in, or knowledge of, the subject or period, but who have strong pre-existing ideological views on the nature of scientific practice into which they try to straitjacket their subject. Do readers base their ideas of what scientists do on such texts? Are the scientists being held up as role models? - in which case, expect some disappointed people when they find that science is not like that. Are they telling some form of progressive story? - aren't we more clever, don't we know more, than those who lived in the past? And so on. Until biographers start to address such fundamental issues of what it is they are doing, we will doubtless continue to be subjected to such inadequate texts as Degrees Kelvin .

Frank A. J. L. James is reader in the history of science, Royal Institution.