Montaño explores the role of electricity in Mexico’s economic and political evolution. She outlines the ways that the coal-deficient country pioneered large-scale hydroelectricity and sought to face the world as a scientifically enlightened “empire of peace.” Montaño documents inventions and adaptations that served local needs while fostering new ideas of time and space, body and self, the national and the foreign. Complicating historical discourses in which Latin Americans merely use technologies developed elsewhere, here Montaño emphasizes a particular national culture of scientific progress and its contributions to a uniquely Mexican modernist political subjectivity.