The first known adding machine, a mechanical calculator called the "Calculating Clock.'' It could add and subtract up to six-digit numbers, based on the movement of six dented wheels geared through a "mutilated" wheel which with every full turn allowed the wheel located at the right to rotate 1/10th of a full turn
Author:
August Friedrich Wilhelm Crome (1753-1833)
Statistical map of production in Europe, possibly the first economic and thematic map (shows geographic distribution of 56 commodities produced in Europe)
Lexis diagram, showing relations among age, calendar time, and life spans of individuals simultaneously (but the paternity of this diagram is in dispute cite{Vandeschrick:2001})