American Scientist

When Physics Became King. Iwan Rhys Morus. xii + 303 pp. University of Chicago Press, 2005. Cloth, $60; paper, $25.

Over the past three decades an increasing number of scholars have proffered histories that explain the content of science by drawing on its sociocultural context. These works typically concentrate on rather specific episodes, often detailing a very limited time span. Iwan Rhys Morus's When Physics Became King draws on scores of such studies in the history of 19th-century physics, tying them together in order to depict the metamorphosis of the discipline from the late 18th to the early 20th century. Morus accomplishes this feat by dividing up the book into a series of historical themes, including the revolutionary aspects of natural philosophy; physical experiments and showmanship; the importance of skill, labor and mechanization to experimentation; physics and imperialism; and the social aspects of precision measurement.

Although Morus covers France and Germany, the majority of the book is dedicated to the analysis of 19th-century British physics. For example, he discusses how a dozen upstart mathematics students at the University of Cambridge during the 1810s, including John Herschel, Charles Babbage and George Peacock, adopted the new mathematical analysis of the French and founded the Analytical Society. These lads wished to wrestle British science away from the grasps of aristocratic gentlemen—epitomized by the president of the Royal Society of London, Sir Joseph Banks—in order to reform both science and society. They maintained that meritocracy, rather than nepotism, was required for physics and the economy to flourish. Babbage and Herschel were committed to maximizing the efficiency of both mental labor and British manufacturing. Efficiency was applicable to both physics and business, or as Morus argues, "Efficiency was the name of the game in both cases, and efficiency was best achieved by due attention to, and proper application of, the laws of nature and the operations of the mind."

Mathematics was believed to discipline the mind. The Analytical Society wanted to revolutionize the mathematical Tripos at Cambridge by having it cover French analytical calculus. Peacock eventually became one of the university's examiners and accomplished this expansion of scope.  By the middle of the 19th century, the Tripos had been overhauled, rendering it much more rigorous, with grueling written tests after the third year. Only those with a sharp mind, combined with physical stamina and the assistance of a good tutor (referred to as a "coach"), could survive. Posh accents (indicative of good breeding), which in the 18th century had been noted approvingly in oral exams, could no longer assist those who were ill prepared.

Morus also offers his readers a fascinating cultural history of electricity. On the one hand, electricity was a critical component of physics in the 19th century. Any self-respecting university in Europe or the United States needed a laboratory that included electrical instruments. On the other hand, electrical experiments were exciting and stimulating; they appealed to a general audience thirsty for good performances. Many "electricians" found themselves happily catering to what some saw as the crass whims of a public fascinated by physical forces. Thus electricity was perched precariously on a precipice, threatening to tip over into the abyss of the curiosity of the "vulgar masses." Not all physicists, however, were concerned with the public's fascination with electricity. They realized that some commercially relevant objects, such as the cable telegraph, offered a model to help physicists understand how electromagnetic waves propagated throughout the ubiquitous, yet elusive, ether that had been posited by British physicists (including James Clerk Maxwell and Oliver Lodge).

Another case in point is that the development of 19th-century physics owed much to the rise of the steam engine during the Industrial Revolution. James Watt's machine not only powered the U.S. and European economies, during the 1840s and 1850s it served as a model for investigating the new science of heat, thermodynamics. Sadi Carnot, James Prescott Joule and James and William Thomson (later known as Lord Kelvin) busied themselves with this new science, contributing critical works on such topics as the mechanical equivalent of heat, the conservation of heat and an engine's efficiency. The Thomson brothers were well aware of the moral implications of the notions of work and waste during an era when toiling was a Victorian value and waste was deemed sinful.

Over the course of the book the reader becomes convinced that the history of physics is a story not of isolated geniuses disengaged from society in ivy-covered towers, but rather of a collection of individuals from diverse walks of life working together in concert. In short, When Physics Became King is a masterfully written historical analysis. Morus's bibliography is comprehensive and provides readers who wish to investigate a particular theme in further detail with an extremely useful resource. The book, which fills most admirably a huge gap in the secondary literature, is a "must read" for undergraduates. I also highly recommend it to historians of science and technology; to general historians, for the understanding it offers of the importance of physics to 19th-century economies and notions of nationalism; and to scientists, for the sense it provides of the importance of sociocultural context to scientific content.