The Türler family’s watch retail business celebrated its 130th anniversary in style with the presentation of a luxurious book that tells the story behind the famous Türler clock that has attracted over 20,000 visitors to the Türler store on Zurich’s Bahnhofstrasse since it was first unveiled on 21 June 1995.

The book, written jointly by the three masterminds behind the project—Franz Türler as the initiator, Ludwig Oechslin as the constructor and Jörg Spöring as the watchmaker—recounts the nine-year period over which the clock was built, including numerous photographs, technical drawings and even the full calculations for the five highly complicated movements used for the planetarium, tellurion, globe, horizon and perpetual calendar displays.

Powered by solar panels fixed to the roof of the building on Paradeplatz where the shop is located, the clock displays periods of time along a staggering scale, from the humble second to the rotation of the heavenly canopy, which completes one revolution in 25,794 years (also known as the Platonic Year, since Plato posited the “perfect year” as the period after which the planets and the fixed stars returned to their original positions.

Appropriately entitled “Das Unikat” in reference to the unique nature of this extraordinary timepiece, the book is currently only available in German (as indeed are many of the fascinating calculations used to construct the workings of the clock).

“Das Unikat” - the book recounting the history and development of the unique Türler clock

The Türler clock in detail

The planetarium Surrounded by the ecliptic with the signs of the zodiac, this movement shows the entire heliocentric system with the sun in the centre. The nine planets move around the sun along their respective orbits. From the inside: The sun, Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, Pluto.

The planetarium mechanism of the Türler clock

The tellurion Within the great circle showing the signs of the zodiac and the months, this movement illustrates the juxtaposed motions of the sun, the earth, and the moon in their constellations. The mechanically sophisticated arrangement emulates the orbit of the moon around the earth as well as the mutual journey of the earth and moon around the sun.

The tellurion mechanism of the Türler clock

The globe This plastic depiction of cosmic correlations, including all solar and lunar eclipses, is based on a complex system composed of six elements with the globe in the centre.

The elements, from inside: 1. The earth with its continents. 2. The moon on a glass sphere. 3. The sun on a two-colour glass sphere with the day/night boundaries. 4. The celestial canopy (rotates once every 25,794 years). 5. Ecliptic with signs of the zodiac. 6. Orientation lines (identical with those applied to the model of the earth).

The globe of the Türler clock

The horizon Visible from the roof of the Savoy building at the Paradeplatz, the 360-degree panorama of the city of Zürich constitutes the stage for the 24-hour dial which indicates the precise motions of the sun and the moon, precisely correlated with and accurately calculated for the clock’s position. It shows the sunrise and sunset, and moonrise and moonset times as well as the changing elevations of both bodies over the horizon. It also depicts solar and lunar eclipses. The 24-hour dial indicates true solar time in Zürich as opposed to «standard» time. Thus, the Türler Clock is the only timepiece in Zürich that indicates the “correct” time.

The perpetual calendar A large main dial and four subsidiary dials indicate seconds, minutes, hours, the day of the week, the date, the month, the year, the decade, the century, and the millennium. Leap days are automatically taken into consideration, including those in years divisible by 100 and 400.

The perpetual calendar mechanism of the Türler clock