Description:This books describes an exhaustive list of inventions created to help with arithmetic operations. For each it gives detailed explanations of their mechanisms and the principles of their functioning. Among them are various adding devices (abacus, addiator, arithmograph, etc.), the arithmetic machines (starting with Pascal and Leibniz), as well as graphic methods (nomographs, integrometers such as planimeters, nomomechanical devices). Scanned by the bibliothèque nationale de France