Instruments · Sundial
Sundial by Ch. A. Sediq, Germany, 1992 (German Clock Museum Museu_ProvidedCHO_museum_digital_29716__technical_number_)
- Maker / attribution
- Ch. A. Sediq (creator)
- Date
- 1992
- Historical period
- Mechanical Renaissance (1990 – 2010)
- Country of origin
- Germany
- Place
- Germany
- Object type
- Sundial
- Holding institution
- German Clock Museum
- Accession / object no.
- Museu_ProvidedCHO_museum_digital_29716__technical_number_
- Catalogue title (original)
- Modell Halbkugelsonnenuhr, Ch. A. Sediq, Ettenheim, 1992 (German)
Record summary
Held and catalogued by German Clock Museum (object number Museu_ProvidedCHO_museum_digital_29716__technical_number_), this is a sundial by Ch. A. Sediq, made in Germany, dated 1992. The Atlas places it in the Mechanical Renaissance period (1990 – 2010) of its Instruments collection. The record is illustrated with 1 photograph.
Assembled from the source record's structured fields. Dates and attributions are given as the source states them; where a field is missing the Atlas leaves it blank rather than estimating.
Catalogue description
Catalogue description from German Clock Museum (German)
Gipsmodell einer antiken Halbkugelsonnenuhr, Ch. A. Sediq, Ettenheim, 1992. (Deutsches Uhrenmuseum Furtwangen)
Shown in the original language of the source catalogue. An editor-reviewed English translation has not yet been published; we do not publish machine translations as authoritative text.
Historical context
Mechanical Renaissance (1990 – 2010)
Mechanical watches return as cultural objects; independent watchmaking flourishes.
Satellite navigation and network time made precise time universal; historic instruments are studied as heritage.
Read the period in the timelineMore instruments from this periodEarlier: Quartz Revolution
Atlas type guide
Sundials and solar time-finders
A sundial tells time from the position of a shadow cast by a gnomon or style. Because the sun's apparent motion depends on latitude, every fixed dial is laid out for a particular latitude, and portable dials either carry a latitude scale or are made for one region. Sundials show local apparent solar time, which drifts against mean (clock) time by up to about sixteen minutes over the year — the equation of time.
Portable dials were the pocket instruments of the sixteenth to eighteenth centuries. Nuremberg and Augsburg workshops produced folding ivory diptych dials with inset compasses; English and French makers sold brass horizontal dials, ring dials and the Butterfield type; Japanese and Chinese makers had their own traditions of compass dials. After mechanical watches became reliable, dials remained in use for setting them, and nineteenth-century heliochronometers were built to correct directly for the equation of time.
What to look for
- The latitude engraved on the dial plate or a latitude arc on the gnomon — it shows where the dial was meant to be used.
- The type of hour lines: equal (equinoctial) hours, Italian or Babylonian hours counted from sunset or sunrise, or unequal temporal hours on early and Islamic instruments.
- An inset magnetic compass and whether a magnetic-declination mark is drawn on its card — a useful dating clue because declination changes over time.
- Maker's signatures and town marks: Nuremberg compass-makers (Kompassmacher) often struck a personal mark and the town's punch.
- Additional scales such as lunar volvelles, wind roses, perpetual calendars or lists of cities with their latitudes.
Dating clues
- Ivory diptych dials are characteristic of Nuremberg between about 1500 and 1700.
- Butterfield-type dials with a bird-shaped adjustable gnomon point to Paris workshops from the late seventeenth century onward.
- Equation-of-time tables engraved on the plate became common after the mid-seventeenth century, once pendulum clocks made the difference between solar and mean time obvious.
General guidance written by the Atlas editors about this kind of object. It is not a statement about this particular piece; for that, rely on the source record above and on physical examination.
Read next:The history timeline
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