On the "Dies Academicus" of the University of Bonn, the Arithmeum will offer special guided tours and an evening lecture:

11:00 a.m. Calculating - Past and Present - Tour of the Arithmeum collection of mechanical calculating machines

1:00 p.m. Geometric-Constructivist Art - Tour of the Arithmeum art collection

3:00 p.m. Calculating with Zeros and Ones - What do the ball-adding machine of Leibniz, the cylindrical mechanical calculating machine of Müller and a modern fully-adding machine have in common? They all add by means of binary numbers. Tour with presentations and explanations.

4:30 p.m. Calculating with Zeros and Ones - Also the machines of Babbage, Hollerith and Zuse calculate by means of binary numbers. - Tour with presentation of the Zuse "Z 25" built in 1967.

6:15 p.m. A fascinating discovery – the mechanical calculating machine of Johann Sauter in Göteborg - Lecture (see overleaf for details).

Admission is free on the "Dies Academicus".