Hörrohr (Abhöranlage)

The engraving depicts a stone structure with a large internal funnel used to capture the conversations of people gathered in a courtyard. A pipe conducts the sound through the walls to a secret listening chamber in an adjacent tower, where a figure is shown eavesdropping. This diagram illustrates the architectural application of acoustics for surveillance and the transmission of sound.

Athanasius Kircher was a key figure in late Renaissance natural philosophy who explored 'natural magic,' or the use of scientific principles to create seemingly miraculous effects. This work comes from his studies on acoustics, where he sought to master the laws of sound to serve the needs of courtly power and secret communication.