In 1904, professor Francesco Cavani, commissioned by the Municipality of Bologna, was tasked with evaluating the stability of the Garisenda Tower. To this end, he developed an innovative monitoring system, based on a plumb line fixed about 40 meters high on the south wall and specialized telescopes, equipped with a double system of lenses and focuses, capable of detecting displacements with precision up to one‐twentieth of a millimeter. The tables attached to his report present in detail the monitoring data, including time series of the eastward and northward displacements, represented at a 20:1 enlarged scale. In this study, the original series were digitized, scaled, and exported for analysis using modern methods. The goal is to extract information on the dynamic characteristics of...