This month we would like to introduce you to the work behind the scenes at the Arithmeum. The exhibits in the exhibition “Crown jewels from the IBM collection on permanent loan to the Arithmeum” are being restored - some of them even in public. As part of this process, Professor Dr. Ina Prinz, Director of the Arithmeum, and Professor Dr. Patrick Rocca, a proven expert in the restoration of historical scientific instruments and clocks, have been able to completely restore the unique prototype of the Arithmaurel calculating machine from 1846 over the past few months. In November 2020, Uni-Bonn.TV offered an insight into the restoration of this calculating machine by Timoléon Maurel, which just recently has been completed. In this video, Professor Dr. Ina Prinz and Professor Dr. Patrick Rocca report on the procedure and the work on this unique object. We would now like to share this insight with you and let you participate in the work of the Arithmeum. The machine is now fully functional again. With its double result unit for multiplications and the addition of results of different multiplications, this automatically multiplying calculating machine was one of the most complex calculating machines built in the 19th century. It was the only calculating machine to have a tens carry which was realized parallel to the transfer of numbers into the result unit. Mechanically, this was possible thanks to the use of planetary gears, which were manufactured with the highest precision at the time.

We would like to take this opportunity to thank Uni-Bonn.TV for the successful collaboration and hope you enjoy this new “Calculating Machine of the Month”, which is now - freshly restored - on display at the Arithmeum. The functionality of this calculating machine and the restoration process will also be documented in detail in a catalogue which will be published in the coming months.