Zimmer tower

The original tower was built no later than 1425, though the precise date of construction is unknown.

In 1812 the tower was sold by the municipal authorities, but after World War I, they repurchased it and slated it for demolition.

In 1930 astronomer and clockmaker Louis Zimmer donated a complex clock which was installed in the old tower, which had to be substantially reconstructed for this.

In 1960 a pavilion for the new clock was built next to the tower to present Zimmer's masterpiece the wonder-clock.

Around one of these dials moves the slowest pointer in the world – its complete revolution will take 25800 years, which corresponds to the period of the precession of the Earth's axis.

The wonder-clocks impressed Albert Einstein, who congratulated Zimmer on the creation of these unusual mechanisms.

On the small square at the foot of the tower an exhibition of the Solar System was arranged with the aid of metallic circles and the rings (circles designate the Sun and planets, rings the orbits of planets).

The Centenary clock has one large dial in the centre, measuring 1.5 metres (4 ft 11 in) in diameter.

The twelve dials around the centre dial show the following (starting from the dial in the 2 o'clock position and going clockwise): the equation of time, the zodiac, the solar cycle and the dominical letter, the week, the globe, the months, the calendar dates, the seasons, the tides, the age of the moon, the phases of the moon and the metonic cycle and the epact.

Every year the Sun describes an imaginary circle around the Earth, called the zodiac.

The zodiac is divided in twelve segments, each denoted by a sign associated with a constellation.

On the inner circle, the hand indicates the current year of the solar cycle.

On the outer circle, the hand shows the corresponding dominical letter.

For leap years, the outer circle will show two dominical letters.

From 1980 to 2007, respectively, there were: This dial marks the seven days of the week, represented by ancient gods and their symbol.

The biggest ship and the flag without the streamer indicate high water.

This globe, colored half-gold and half-blue with golden stars, shows the phases of the moon.

The inner ring shows the epact, which is the age of the moon on the first of January of the current year.