Public clocks like the one hanging from the Jewelers Building have a lengthy history rooted in the human impulse to mark time in one way or another and to accrue power through control over the time. They date to the sundials, clepsydras, and incense clocks of antiquity and to the earliest mechanical clocks of the twelfth century. After the thirteenth century, clocks and bells indicating the hours spread through villages, small towns, and urban centers in Western Europe. The parameters within which the earliest clocks functioned were broad: a hand moved either direction (rather than only “clockwise”), and dials indicated three, four, sixteen, or twenty-four hours, in addition to the now conventional twelve hours. By the end of the fifteenth century, hands moved clockwise on dials with twelve equal hours. In early modern Europe, the public clock was “an indicator of modernity,” like the period’s other technological and social innovations, mills and schools. Public clocks dotted the public spaces of capital cities like Paris, London, and Berlin; port cities like Bristol, England; and colonial cities like Quito, Tlaxcala (Mexico), New York, Philadelphia, and Boston. By the middle of the eighteenth century, clocks constituted the spatial and symbolic center of urban life in Western Europe, Spanish North and South America, and British North America.