Alexis McCrossen's Marking Modern Times is a cultural and material analysis of the rise of clock time in the United States through the nineteenth and early twentieth centuries. It tells the story of how modest levels of timekeeping technologies and a bewildering array of time authorities gradually gave way to national time standardization and an explosion of personal timepieces and public clocks. In its telling, McCrossen successfully avoids one-dimensional explanations, instead examining a wide variety of people, places, technologies and social practices which together influenced the adoption of clock time. Of these many factors, her argument comes to focus on the unique role of public clocks: for increasing public awareness of clock time, for disseminating (even if imperfectly) standardized time, and, most profoundly, for helping to naturalize what was essentially a social, political and mechanical approach to time. Even as the golden age of monumental clocks came and went in the early decades of the twentieth century, the acceptance of time as a measure of hours and minutes continued and remains firmly established in the psyche and social practices of modern life.

Not surprisingly, the most cogent aspect of McCrossen's argument is her sustained examination of timekeeping in public space, a practice which she shows to have been wrought with complexity. Residents of cities and towns depended on public clocks to mark a shared sense of time, but utilized pocket watches to carry that time into the interior spaces of their homes where mantelpiece clocks were set. But not all public clocks were treated equally; part of negotiating time in urban space depended on a socially accumulated understanding of which clocks were agreed to be most accurate. Diving into this urban milieu, the book is likewise rich in analysis of the placement of clocks within the built environment, from their prominent display on municipal architecture, to their hiddenness in factory settings, to their movement over time from the interior of railway stations to the more conspicuous exterior. Drawing on public reaction to the unveiling, maintenance and sometimes removal of public clocks, she finds rich evidence of the intensity of public attachment to such devices and their perceived usefulness in daily life (e.g. pp. 151ff). As rich as these details are, they ultimately serve a weightier point for McCrossen: that, without public clocks, time as a mechanical measure of hours and minutes could not have become so deeply embedded in the modern psyche. ‘Modern time discipline depended on this sense of clock time as impartial and transcendent, like the weather’, she writes. ‘Only public clocks could make the case that this was indeed so’ (p. 22). On this score, government sponsored clocks served the purpose more readily, as they were most often perceived as a public service. In contrast, clocks erected by private businesses were more susceptible to negative reactions – such as when an overzealous Milwaukee mayor had jewellers’ sidewalk clocks torn down as part of a city ban on advertising signs (pp. 128–31).

If public timekeeping is the book's main concern, it is clearly not the only one. McCrossen examines the contributions of an array of individuals and groups – from jewellers, to government officials, to clock manufacturers, to railroad companies – as well as the varied timekeeping practices of the American public more broadly. No single dynamic is presented as decisive on its own; rather, the reader is left with the sense of a gradual groundswell of interconnected interest and desire for clock time. Intriguingly, technology plays a rather ambivalent role in this narrative, most often lagging well behind popular interest in clocks so that the number of timepieces, both public and private, far outpaced the ability to bring them into any kind of sustained co-ordination. Political and social developments may not have supplanted technology, but they frequently proved just as vital, most notably in the establishment of national time standardization in 1883 together with public willingness to abide by it. This sense of diffused causality – with all its attendant details – can sometimes be disorienting, but it ultimately bolsters a key contribution of the book, namely, that technical achievements are often just as powerful as an ideal as they are in realization (p. 117).

Marking Modern Times is an innovative contribution on a key historical shift in modern life. The nuance of McCrossen's argument is complimented by a variety of rich visual examples of clocks, advertisements and urban streetscapes. Some concluding reflection on the broader implications of her central argument on public space would have been welcome, but would only be a minimal addition to what is already an engaging and substantive work.