With the precision and sophistication characteristic of a late eighteenth-century chronometer, Paul Glennie and Nigel Thrift set out to explore the preindustrial history of clock time, what might on its face appear to be a non sequitur. Shaping the Day: A History of Timekeeping in England and Wales, 1300–1800 is a rigorously researched, ambitiously conceived, and richly detailed study of the practice of timekeeping—its origins, dynamics, and impact—set in a broad social and cultural context. It is also a highly technical examination, notwithstanding the authors’ gift for clear-eyed prose. In the introduction, they suggest that nonspecialists might wish to bypass parts of two early chapters. In truth, the entire book is best suited for specialists, whether social and cultural historians, geographers, or historians of technology.

The research undergirding Shaping the Day is deep, mined from almanacs, diaries, court records, and merchants’ ledgers. Ship inventories and tide tables figure in an intriguing analysis of seafaring time. The authors also rely upon an impressive array of secondary sources drawn from a variety of disciplines. That said, they do not shrink from confronting a number of distinguished authorities, including both technological determinists and others who have instead viewed instruments of timekeeping as “simply social inventions” (42). Past contributions by David Landes, Jacques Le Goff, and Carlo M. Cipolla are among the targets, as is Dava Sobel's best-selling book Longitude (New York, 1995), which is faulted for its depiction of the brilliant clockmaker James Harrison as an untrained “lone genius.” In fact, Harrison's upbringing in north Lincolnshire, which was not nearly as isolated as Sobel suggests, exposed him to many of the mysteries of timekeeping, particularly in light of his familiarity with church and household clocks and the craftsmen who kept them running. Indeed, the prevalence of clocks and other mechanical instruments of timekeeping in both England and Wales is one of the book's central leitmotifs.

Glennie and Thrift reserve their sharpest criticism for E. P. Thompson's iconic essay, “Time, Work-Discipline and Industrial Capitalism,” along with the vast body of historians who have all too readily embraced its contention that clock time acquired heightened popularity in the late 1700s as a means to regulate labor and enforce rigid conditions in factories. Before long, this new work regimen—the tyranny of the clock—came to be internalized by the laboring classes themselves. By contrast, insist Thrift and Glennie, “from very much earlier the use of clock time was both assumed and promoted by activities in several facets of life” (131–32), including public markets, religious and civic events, and community curfews.

More specifically, Glennie and Thrift contend that the late Middle Ages witnessed a chronological revolution, marked by increasing reliance on clock time incorporating the use of “equal-hours” as a common increment (409). A “second revolution” occurred by the 1600s, which saw “an increasing subdivision of hours,” and was followed by the introduction of minutes and, “more rarely,” seconds “for all sorts of purposes, not least by people of low status and limited training” (410). By the succeeding century, yet a final revolution occasioned “the emergence of more specialized temporal communities,” such as navigators and astronomers, who required greater accuracy and precision (411).

The authors make a powerful case for the early prevalence of clock time, in contrast to traditional techniques of natural timekeeping. At times, to be sure, they overreach. Had Glennie and Thrift endeavored, with the same fervor, to uncover evidence demonstrating the persistence of natural time, I suspect that they might have been surprised by the degree to which large numbers of people in north Lincolnshire and elsewhere still looked to both the shadows and the heavens, not to mention the enlarged pupils of their sheep among other external changes in animals and foliage, to gauge the day's progression. After all, as late as 1887, Thomas Hardy wrote in The Woodlanders of the “countryman”—forced to rely upon nature—who saw “a thousand successive tints and traits in the landscape which are never discerned by him who hears the regular chime of a clock” ([London, 1991], 99–100).

But make no mistake. Shaping the Day (and night) is a stunning achievement, with major implications for our understanding of technological innovation and the role of timekeeping in early modern Britain. One of the book's many contributions is a final chapter that affords an agenda for future studies as well as a summary of the authors’ formidable research.