Instruments · Astrolabe

Astrolabe, Italy, 1495-1505

DocumentedDocumented from the holding institution's catalogue record.

Maker / attribution: Unrecorded in source
Date: 1495-1505
Historical period: Renaissance Horology (1400 – 1600)
Country of origin: Italy
Place: Italy, Italy
Object type: Astrolabe
Dimensions: overall: 160 x 25 x 108 mm
Holding institution: Science Museum Group, London
Accession / object no.: 1938-428
Credit line: Mr W.E. Miller
Catalogue title (original): European astrolabe, 1495-1505

Record summary

Held and catalogued by Science Museum Group, London (object number 1938-428), this is an astrolabe, made in Italy, Italy, dated 1495-1505. The Atlas places it in the Renaissance Horology period (1400 – 1600) of its Instruments collection. Recorded dimensions: overall: 160 x 25 x 108 mm. 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

Science Museum Group description

Italian brass planispheric astrolabe with a single plate for the latitudes 42 & 45 degrees and for 48 degrees on the inside of the womb with shadow dial and unequal scale on the reverse, c. 1500 Dated to the start of the sixteenth century, this unsigned brass astrolabe is thought to be Italian in origin. This front view shows the moveable fretwork plate called the rete that denotes star positions by short curved pointers. The astrolabe is in essence a model of the universe that an astronomer could hold in their hands. Popular in Medieval and Renaissance Europe, its many uses included timekeeping, astrology and surveying. The astrolabe is a two-dimensional depiction of the heavens whose layout is achieved using the mathematical technique of stereographic projection. From its origins in the Ancient World, Islamic astronomers developed the astrolabe from where it spread to Europe.

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 timeline More instruments from this period Earlier: 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.

Mechanisms mentioned

No escapement or complication is named in the source record. See the encyclopedia for how such pieces work.

Record completeness

Maker or attributionNot in source
DateRecorded
Place or countryRecorded
MaterialsNot in source
DimensionsRecorded
Narrative descriptionRecorded
Inscriptions / marksNot in source
ProvenanceNot in source
Several photographsNot in source

Editorial status: Documented — facts as published by the source; not independently verified by Atlas editors.

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Sources & image rights

Record source: Science Museum Group, London.

Image rights: CC BY-NC-SA 4.0 (Science Museum Group) — permission review.

Images are hosted by the Atlas for study and credited to their owner. Rights holders may request correction, credit changes or removal via the editorial office.

Cite this record

"Astrolabe, Italy, 1495-1505." Science Museum Group, London, 1938-428. Catalogue record in The Horology Atlas, WatchMuseum.org, https://atlas.watchmuseum.org/museum/astrolabe-italy-1495-1505-d335f3.