Oil lamp clock
The oil-lamp clock also Öluhr or time lamp called, is a glassy oil lamp which is provided with markings. At the booth of the remaining oil can be the last time read. Oil clocks belong to the elementary clocks .
The oil lamp clock actually only consists of an oil table lamp, the glass container of which has a small opening at the bottom through which the oil is sucked in by a wick . The height of the oil level in the reservoir is a measure of the time that has elapsed. The thickness of the wick is chosen so that the oil in the lamp is used up by the flame as precisely as possible according to the hour scale on the glass container. Served as fuel dark brown rapeseed oil or Tran . Tran was typically used because it burns cleaner and more evenly than oil.
If you filled the oil container full in the evening and lit the lamp, you not only had lighting for the whole night, but also approximately the time display. Due to the fuel consumption of the lamp, the oil or transparent level in the glass reservoir sank, which meant that the time could be read on the scale. Because the pressure of the oil caused uneven consumption, depending on the level, and the hour scales on the cylindrical container were usually displayed linearly, the first hour of the evening was much shorter than the last hour of the morning. To compensate for this, the oil container was later given the shape of an upturned pear. This measure made it possible to keep the lengths of the hours almost the same.
Oil clocks are clocks that have the advantage over other elementary clocks that you can read the time in the dark. However, this type of timepiece was very imprecise.
Little is known about the origin of the oil clocks. From the 16th century, glass oil lamps were provided with markings to measure time. They did not become more common in Central Europe until the 16th century, but were then very popular until the middle of the 19th century. From then on, the frame of the lamp is mostly made of pewter , as is the hour scale attached to the oil container.
- Libuše Urešová: Old clocks ; Publisher Verner Dausien; Hanau / M 1990 ISBN 3-7684-1697-6
- Archaeological Museum Hamburg: Oil clock
- Zeno: Meyers Großes Konversations-Lexikon 6th edition 1905–1909 , oil clock
- Gerhard König: The clock (history - technology - style) ; Koehler & Amelang Verlag; Leipzig 1991; ISBN 3-7338-0065-6 , p. 41
- Viktor Prösler: Callwey's handbook of clock types ; Calwey Verlag; Munich 1994 ISBN 3-7667-1098-2 , p. 17
- Reinhard Meis: The old clock ; Vol. 1. Klinkhardt & Biermann, Braunschweig 1978, ISBN 978-3781401167 . P. 82ff.
- Horst Landrock : Old clocks - rediscovered ; VEB Verlag Technik Berlin 1981; P. 18f
- Fritz von Osterhausen: Callweys lexicon ; Munich 1999; ISBN 3-7667-1353-1 ; P. 231