While makers of mechanical calculating machines cited the limitations of printed tools as aids to calculation, no calculating machine was “reduced to practice” until the nineteenth century. Printed aids to calculations simple and complex were, on the contrary produced, sold, and used in large numbers. Babbage’s famous machine, never brought to practical use, was designed not for individual desktop calculation but to automate the printing of tables. The talk surveys the material culture of calculation, so brilliantly captured in Columbia’s David Eugene Smith Collection, from the mid seventeenth to the early nineteenth century. Questions? email: Gerald Cloud