At the heart of this chapter lies a set of interdependent technologies whose development and application had remarkable global resonance and reach. Steamships, undersea cables, and wireless telegraphy rose to prominence during an era of heightened imperial expansion and rivalry from the second half of the nineteenth century. These industrial technologies of transport and communications that developed in distant metropoles are generally argued to have ‘globalized’ the Pacific, hooking this vast ocean into worldwide circuits of exchange. Yet it was only with the advent of a Pacific world networked through steam and electricity that such circuits were in effect global for the first time. The world’s largest ocean was fundamental to any such claims of world-spanning, earth-girding effects.