The Clock Tower (Zeitglockenturm) was Bern's first western city gate (1191 – 1256) and formed the boundary of the first city extension. Today it is one of Bern's most important sights. The ornate astronomical calendar clock was created in 1530.
The tower clock was the city's main clock and therefore had an authoritative function in Bern. It was from there that travel times indicated on the hour stones along the cantonal roads were measured. Length units – formerly cubit and fathom, today meter and double meter – for public inspection are displayed in the arch of the gate.
History
The Clock Tower with its famous clock is un-doubtedly one of the most important tourist at-tractions of the city of Berne.
As the city expanded around 1220 from the bend of the river Aare up to the region of today's Clock Tower a West gate tower was built as part of a defence wall. The town grew very fast and ex-panded to the West, so that the West gate tower lost more and more its purpose of defence. First transformed into a prison it was immediately re-erected, after the fire of 1405, to host a big bell and a mechanical clock. Thus, it was called the Clock Tower ever since.
Though it has undergone many changes, the Clock Tower kept its purpose of announcing the hours to Berne's people until today. Its time was classified as the main time in the state of Berne. The course of all other clocks was based on the one in the Clock Tower.
The Main Movement
Between 1527 and 1530 Casper Brunner built the monumentaland artistic mechanisms, which controls the whole installation:the astronomical dial, both the large dials on the East andWest fa�ades, the hourly chime and the automata. We dare say that it is one of the greatest clock mechanisms ever builtand it has basically survived until the present day.The clock frame consists of a wrought-iron, late Gothicsupported construction, measuring 2.50 m in length,1.70 m in depth and approx. 2.20 m in height. The wholemechanism contains 5 different gears: The main train witha pendulum (originally foliot), the quarter chime, the hourchime and two automata gears.
The five gears are driven by stone weights with a powerreserve of about 28 hours. Therefore the weights with a totalweightiness of 450 kg have to be pulled up every day.The Astronomical ClockThe astronomical clock was first mentioned in the cityaccounts of 1444 when it had to be repainted. It thereforedates from the early 15th century and presumably belonged tothe first original movement (soon after 1405).In 1530 Brunner took over the astronomical clock withoutmaking any major changes. We have a good idea of what itlooked like in those days thanks to a contemporary painting,which is still extant (cf. fig. 4).A astrolabe type of dial is well cognised.
The twelvesomewhat arbitrarily arranged signs of the Zodiac can beclearly seen. Sun and moon orbit the zodiac, while a handindicates the hours on the outer edge of the dial (numberedin reverse order from I-XII).The lines on the planisphere indicate a southernstereographic projection. In the corners of the paintedborder, symbolic faces indicate the four winds. Above thedial the Roman deities Venus, Mars and Jupiter are paintedon the wall together with their attributes.The musical oriel is depicted on the right side of the dia
The astronomical clock
The astronomical clock was first mentioned in the city accounts of 1444 when it had to be repainted. It therefore dates from the early 15th century and presumably belonged to the first original move-ment (soon after 1405).
In 1530 Brunner took over the astronomical clock without making any major changes. We have a good idea of what it looked like in those days thanks to a contemporary painting, which is still extant. A astrolabe type of dial is well cognised. The twelve somewhat arbitrarily ar-ranged signs of the Zodiac can be clearly seen. Sun and moon orbit the zodiac, while a hand indicates the hours on the outer edge of the dial (numbered in reverse order from I-XII). The lines on the planisphere indicate a southern stereo-graphic projection. In the corners of the painted border, symbolic faces indicate the four winds. Above the dial the Roman deities Venus, Mars and Jupiter are painted on the wall together with their attributes. The musical oriel is depicted on the right side of the dial.