This article examines the ways of knowing that govern public constructions of knowledge in the manufacture of the mobile phone—its cultural meaning, sociality of labor, and environmental consequences. It does so to consider the "material epistemology" of the mobile phone, the way in which one comes to know these devices, especially through the devices themselves. In modern manufacture, the incorporation of corporate supplier audits and investigative reporting into public discourse reveals an epistemology of production that is primarily imagined, rather than historically and ethnographically realized. Although the public epistemology of the mobile supply chain is built from the model of the telephone and telegraph, these networks were themselves mystified, displaced, and obscured. This is illustrated by examining material and conceptual differences between the historic supply chain of the telephone manufacturer Western Electric, and those imagined for contemporary companies like Apple.