Astrolabe by Gemma Frisius, Belgium, 1500–1599 — view 1 of 1
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Instruments · Astrolabe

Astrolabe by Gemma Frisius, Belgium, 1500–1599

DocumentedDocumented from the holding institution's catalogue record.
Maker / attribution
Gemma Frisius (creator)
Date
1500–1599
Country of origin
Belgium
Place
Belgium
Object type
Astrolabe
Accession / object no.
AP_10368158
Catalogue title (original)
Flemish Astrolab (English)

View the source record ↗

Record summary

Held and catalogued by Royal Institute for Cultural Heritage (object number AP_10368158), this is an astrolabe by Gemma Frisius, made in Belgium, dated 1500–1599. The Atlas places it in the Renaissance Horology period (1400 – 1600) 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

The source record does not include a narrative description. The structured fields above are reproduced from it.

Historical context

Renaissance Horology (1400 – 1600)

Spring power makes clocks portable; Nuremberg and Augsburg produce the first watches; the Prague Orloj is built.

Instrument-making flourished in Nuremberg, Augsburg, Louvain and London: ivory diptych dials, astronomical compendia, astrolabes and nocturnals for wealthy patrons, navigators and scholars.

Read the period in the timelineMore instruments from this periodEarlier: Medieval Period

Atlas type guide

Astrolabes, quadrants and astronomical compendia

The planispheric astrolabe is a two-dimensional model of the sky. A pierced rotating star map (the rete) turns over a plate engraved for a particular latitude; by aligning a star or the sun with its observed altitude, the user can read the time of day or night, the time of sunrise and sunset, and solve many other astronomical problems. Developed in the Hellenistic world and refined by astronomers in the Islamic world from the eighth century, it reached Latin Europe through al-Andalus.

Quadrants, compendia, armillary spheres and later orreries belong to the same family of instruments that model the heavens. They were teaching tools, status objects and practical time-finders. Many surviving examples are signed and dated, which makes them important evidence for the history of instrument-making workshops in Baghdad, Isfahan, Lahore, Toledo, Louvain, Nuremberg, London and elsewhere.

What to look for

  • The latitudes engraved on the plates — they show which cities the instrument was made for.
  • The script and calendar used: Arabic or Persian inscriptions, abjad numerals, Hebrew or Latin text indicate tradition and region.
  • The design of the rete: the number of named stars and the style of the star pointers changes by region and period.
  • Shadow squares, unequal-hour lines and zodiac scales on the back (dorsum).
  • Signatures, dedications and dates, often hidden on the throne (kursi) or the back.

Dating clues

  • Signed and dated astrolabes allow precise dating; undated ones are attributed by star positions on the rete, which shift slowly through precession.
  • Gothic-style retes with tracery are typical of European instruments of the fourteenth and fifteenth centuries.
  • Printed paper astrolabes and planispheres became common from the sixteenth century onward.

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.

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