As in the pilgrimage church of Birnau, Thumb made use of two architectural devices in Mengen, Germany (1741-1744): 1. He added a continuous gallery connected to the organ gallery halfway up the wall. 2. He created space for two side altars with two arched cantilevers (conches) in the fourth nave axis. For the project "Mengen" in 2003 in the Generallandesarchiv Karlsruhe numerous floor plans and elevations were made accessible, unknown up until then.
