born April 22, 1592, Herrenberg, Württemberg
died Oct. 24, 1635, Tübingen
German astronomer, mathematician, and cartographer.
In 1623 he invented one of the first calculating machines. He proposed to Johannes Kepler the development of a mechanical means of calculating ephemerides (predicted positions of celestial bodies at regular intervals of time), and he contributed to the improvement of accuracy in mapmaking.