This talk examines the intertwined histories of interior lives and failing machines. It explores how modern observers from the late-18th to the early 20th centuries understood the failure of machines as a problem of the self— a problem of the kinds of people that failing machines created, or threatened, or presupposed. The talk focuses on two episodes from this history of broken worlds. The first investigates anxieties over the potential failure of the guillotine during the early French Revolution. Against the traditional view of the decapitation machine as a self-evident product of Enlightenment penal reform, the talk argues that the guillotine was originally conceived as a “sentimental machine”: a device shot through with anxieties about failure and born out of the union between a profoundly public, late-18th century public psychology on one hand, and the contemporary mechanical arts on the other. Turning to early 20th-Century America, the paper examines how one of the central graphic technologies of Scientific Management — the Gantt Chart — grew out of attempts to create intricate psychic and cultural linkages between two kinds of failure in Progressive-Era America: failure as a condition of industrial machinery, and failure as a kind of person. For its creator, Henry Gantt, the chart formed part of a project of racial containment: a vision that kept black workers out of northern factories by encoding a relationship between whiteness and efficiency, providing a formalism for white racial uplift. Against the backdrop of the Great Migration, the charts combined with racist union practices, anxieties about black mobility, and fears of racial degeneration, to create northern industrial concerns as closed white democracies that cultivated technological selves. Linking those developments to our own worries in the early-21st century, the talk encourages us to see the history of modern technology as a history of the intersections between failing machines and historical selves, and of the social orders they both made possible.