Conceived by Father Francesco Borghesi and constructed in collaboration with him by Antonio Bertolla at Mocenigo in South Tyrol, now in Northern Italy. The movement has no hands; the four concentric silvered brass ring dials turn independently, being read from a cursor on the glass in the hood which covers them. In addition there are subsidiary dials at right and left below and at top center of these concentric dials in addition to ten openings in the lunette through which readings may be read from small dials located behind the dial proper. This main dial plate is gilt brass richly and skillfully engraved with both figures and inscriptions including the dates 1763 and 1764 in chronograms.
The clock indicates the hours, minutes, day of the week, day of the month, name of the month, number of the current year, intercalary letter of the Sunday date of feasts of the church, movable dates of the year, solar cycle, Golden Number, planetary forecasts of each year, mark and position of master star, phases of the moon, moon's meridian time, all movements of the moon in longitude, latitude, altitude and eccentricity, all movements of the sun in longitute, latitute, altitude, and eccentricity, the solar eclipses, the lunar eclipses, notes of future occurrence of both solar and lunar eclipses, the past occurrence of lunar eclipses, the duration of solar and lunar eclipses indicated, indicates the magnitude of solar and lunar eclipses indicated, notes the circumstances of the time of solar and lunar eclipses, provides the true quadrangulation of the sun and moon and strikes the hours and quarters and repeats the strike.
