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Plane astrolabe, 16th century — view 1 of 2
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Instruments · Plane astrolabe

Plane astrolabe, 16th century

DocumentedDocumented from the holding institution's catalogue record.
Maker / attribution
Unrecorded in source
Date
16th century
Country of origin
Unrecorded in source
Place
German?
Object type
Plane astrolabe
Materials / technique
gilt copper
Dimensions
diameter 88 mm
Holding institution
Museo Galileo, Florence
Accession / object no.
Inv. 1106
Credit line
Museo Galileo, Florence
Catalogue title (original)
Plane astrolabe (English)

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Record summary

Held and catalogued by Museo Galileo, Florence (object number Inv. 1106), this is a plane astrolabe, made in German?, dated 16th century. The Atlas places it in the Renaissance Horology period (1400 – 1600) of its Instruments collection. Materials and techniques recorded by the source: gilt copper. Recorded dimensions: diameter 88 mm. The record is illustrated with 2 photographs.

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 — Museo Galileo

This small astrolabe comprises three tympanums for latitudes 40°/45°, 42°/36°, and 50° (corresponding to Spain, Italy, and France). There is a rete (extensively damaged) and an alidade. The limb of the mater is graduated and divided into 24 parts. The back is inscribed with the zodiacal calendar and the shadow square for surveying. Provenance: Medici collections.

Provenance

Medici collections

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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