Engineers are empire-builders. James Watt, Isambard Kingdom Brunel, Robert Stephenson and a host of lesser known figures worked to build and expand personal and business empires of material technology founded on and sustained by durable networks of trust and expertise. In so doing these engineers and their heirs also became active agents of political and economic empire. Indeed, steamships, railways and electric telegraph systems increasingly complemented one another to form what one early twentieth-century telegraph engineer aptly termed 'our most powerful weapon in the cause of Inter-Imperial Commerce'. This book provides a fascinating exploration of the cultural construction of the large-scale technologies of empire. The book begins with an analysis of collective adventures in exploration, mapping and measurement. Subsequent chapters take the reader through technologies of power (especially steam), the refinement of these powers in steamships and in railways, and the mechanisms of communication (especially electrical telegraphy) by which those powers were promoted and controlled. In following these paths, the reader will encounter many manifestos of promise - often visionary, sometimes extravagant, occasionally sober - issued by engineers throughout the long nineteenth century in their efforts to command authority among their peers, to win the confidence and trust of their prospective investors, and to excite the enthusiasm of wider publics for often-spectacular engineering projects adapted to the service of nation and empire.