Pursuing Power and Light: Technology and Physics from James Watt to Albert Einstein

Pursuing Power and Light: Technology and Physics from James Watt to Albert Einstein, Bruce J. Hunt, Johns Hopkins U. Press, Baltimore, MD, 2010. $45.00 (182 pp.). ISBN 978-0-8018-9358-2

Bruce Hunt’s fine introduction to the history of physics in the 19th century is couched in a long tradition of studies linking science and technology. As is common in this tradition, science and scientists are more central to Pursuing Power and Light: Technology and Physics from James Watt to Albert Einstein than are technology, engineers, or inventors. The book’s strong treatment of thermodynamics, kinetic theory, and electromagnetism befits the author of The Maxwellians (Cornell University Press, 1991) and one of the foremost authorities on James Clerk Maxwell and his followers.

For historians of science and technology, Pursuing Power and Light breaks no new ground. Hunt takes us through such familiar territory as the problems posed by steam engines and the search for increased fuel efficiency; the construction of new theories of heat and the emergence of the kinetic theory of gases; the successive formulations of what would become the first and second laws of thermodynamics; and the lengthy campaign to integrate new discoveries about magnetism and electricity into the classical worldview. Most of the usual suspects show up: Sadi Carnot, James P. Joule, Pierre Simon Laplace, Maxwell, William Thomson (Lord Kelvin), Hermann von Helmholtz, and others. The book is an excellent guide to this well-trodden terrain, particularly for students who will have heard the names in passing but have little sense of how they relate to one another or to the larger structure of physical theory.

Throughout the book, technology and engineering are used to stir the physicists to action, but are not examined or explained on their own merits. In that way, Hunt unfortunately follows many of the historians of physics before him. His attempts to highlight technology and engineering, with such chapters as “Steam and Work” and “Electric Power and Light,” fall short. For example, sidebars embedded in the text serve to sketch out the workings of the three basic models of 18th-century steam engines, but readers are left with the impression that nothing important happens in steam-engine design after James Watt’s condenser and Richard Trevithick’s high-pressure engines. The reader never learns that, thanks in no small part to the thermodynamics that emerged from the efforts to improve them, the steam engines of the middle and late 19th century barely resembled those of earlier generations.

The situation gets a bit more complicated when Hunt links electrical theory to practice, first in telegraphy and then in light and power systems. But there too, his sure-footed and sometimes even elegant exposition of theory gives way to rather spotty and arbitrary discussions of the technical challenges that remade communications and light in the second half of the 19th century. Telegraphy, because of Thomson’s central role in it, does not fare too badly, although telephony—and the wonderful linkage between acoustics and electricity that it represents—is ignored altogether.

The chapter on electric light and power is surprisingly out of focus. For example, we learn about electric chairs and some of the messier public battles between advocates of DC and AC electric systems, but remarkably little about how the hard problems of power transmission, load balancing, and generator design were solved. There is a nice discussion of how electrical engineering education in some countries originated in physics departments, but almost nothing about electrical engineering as a discipline. Readers will look in vain for the name of Charles P. Steinmetz in the book’s index, despite his standing as the archetypal and most famous electrical engineer of the first professional generation.

These shortcomings do not detract from the book’s core value—Pursuing Power and Light is the best and most up-to-date treatment, especially for undergraduates, of the key concepts and figures of 19th-century physics. Hunt’s writing style is very readable, his explanations are clear without being condescending, and when he is on comfortable ground, as when discussing Maxwell and his followers, there is no one better.