Relative to those other great nineteenth-century annihilators of space and time, the railroad and the steamship, the humble telegraph has been given short shrift by economic historians. Roland Wenzlhuemer's new book represents a welcome contribution in its tale of how telegraphy shaped, and was shaped by, the process of globalization.

The central aim of the book is to unpack the agency with which we imbue the telegraph qua technology, primarily by recognizing its manifestation in networks and by viewing such networks as not merely constraints on individual, corporate, and government actions, but also as outcomes of such actions. This motivates an exploration of the intentions and actions of both users and designers of telegraph networks, and suggests an important analytical distinction between network structure and use. Wenzlhuemer focuses on the latter half of the nineteenth century and nearly exclusively on the British Empire. Given the subject of globalization, following the Union Jack in this period is eminently sensible, though it necessarily sidesteps another important theatre for telegraphy, the United States, as well as numerous other roles it might have played, from domestic political or market integration to altering the geography and organization of production.

Wenzlhuemer begins by laying out a conceptual framework (chapter 2), drawing primarily on the vocabulary of sociology. He defines the notion of spaces, in which actors are embedded, and networks, which shape interactions across such spaces. The essence of the telegraph in this view is the wedge it drives between communication and geographic space by dematerializing long-distance information flows. He then surveys the technological history of the telegraph (chapter 3), from the optical systems of eighteenth-century France, through the famous British and American electrical experiments of the 1830s to the maturing networks and submarine conquests of the 1860s and 1870s. He proceeds to a literature review (chapter 4) of the impact of telegraphy in four domains: empire, commerce, news, and culture. This survey and review are necessarily superficial, given their chronological and disciplinary breadth, but their scope is impressively thorough. Readers looking to orient themselves in many dimensions of telegraphic history will be amply rewarded by wading into the footnotes of these early chapters.

The remaining four chapters constitute the meat of the book, using empirical tools from social network theory to analyze archival data on historical telegraph networks. The primary sources are lists and maps drawn up by the precursor to today's International Telecommunications Union, as well as administrative reports and surveys from the United Kingdom and British India. These are framed by interesting qualitative insights throughout, drawing on informal but telling anecdotes, jokes, and apocrypha alongside formal press and administrative accounts.

Wenzlhuemer first maps the growth of submarine cable infrastructure over the last four decades of the century (chapter 5), documenting contemporaneous trends in transmission speed (using lags in The Times' reporting in London of ship arrivals in distant ports) and British trade with newly connected countries, though the latter correlations are inconclusive. The author follows this by studying the centrality of nodes in European and global networks (chapter 6), using a battery of standard network-analytic metrics. These suggest a tight-knit European network, with major imperial capitals as primary hubs alongside a second tier of well-connected Dutch, Belgian and Swiss cities. Globally, London is even more central, and a clear axis emerges, stretching from the eastern United States to Australia via London and South Asia. Structure and use are contrasted here using data on external traffic flows by country.

The final two chapters feature two case studies using more disaggregated data. In the United Kingdom (chapter 7), Wenzlhuemer exploits a pre-nationalization survey to map out structural differences in the three major private networks as well as the intensity of telegraph use at the district level. Here, the inequality in network structure, which privileged London and the major cities of the North as central hubs, pales besides inequality in network use: the top percentile of stations handled two-fifths of traffic, for instance. In contemporary India (chapter 8), where the telegraph was from the first a tool of imperial administration for the East India Company, the network structure featured less differentiation in node centrality, but also demonstrated substantial inequality in use, with the major imperial towns of Bombay and Calcutta unsurprisingly dominant.

Overall, despite providing a rich sociocultural history of the telegraph and useful descriptive analyses of actual networks, the book falls somewhat short of its broader ambitions: the data, primarily cross-sectional in coverage, are too coarse to support strong generalizations about the interplay between telegraphic structure and telegraphic use, and between these two and the process of globalization. Nevertheless, the book is obviously essential reading for historians of globalization or telegraphy, and will clearly be worthwhile for many other readers, including those interested in the economics of information, the political economy of imperialism, and the use of network analysis in history.