Javier Martín Artajo and Jacinto del Buey Pérez have formed a magnificent tandem, contributing their computer knowledge and their skills as a photographer, their patience and tenacity to methodically inventory almost all of the solar quadrants found in this province. The appearance and description of a significant number of Mass clocks that mark canonical hours is surprising. They are engraved on the south face of the churches and their purpose was to complete the liturgical acts.