The quartz-controlled Hermle skeleton movement with astronomical indications has an astrolabe at the top to complement the hour and minute display. The sun, moon and earth are moved by the movement via the gear train visible at the top in their daily, monthly (moon around the earth) and annual rotation (earth around the sun) in a true-to-life time sequence. The date and month positions are shown as signs of the zodiac in the upper display level on a decorative picture scale on the horizontal clock disc. The clock shows the Earth's orbit around the sun once in a year, whereby the Earth revolves around itself once every 24 hours. At the same time, the moon orbits the earth once every 29 1/2 days, turning once on its own axis, so that the individual phases of the moon can be recognised from the earth. The earth passes through the 12 signs of the zodiac, months and days, which can be read on a flat, cylindrical dial. The time sequences are shown identically, but not the geometric dimensions.

Movement: Hermle quartz skeleton movement W2987, display of month/date, signs of the zodiac etc., running time with an alkaline manganese battery, > 1 year, baby cell type.
Glass bell: The crystal glass bell is mouth-blown in the old artisan tradition. Small irregularities and faults are unavoidable with this handcrafted production method and are therefore characteristic.