Hispano-Moorish Astrolabe
Record status
Individual type · partial
Period
circa 1260
This unsigned brass planispheric astrolabe measures 145 mm in diameter. The mater is constructed from three riveted layers, with the central layer cast integrally with a three-lobed throne featuring simple decoration.
Suspension is facilitated by a ring, shackle, and swivel. The limb displays scales for hours and degrees. The Gothic-type rete includes 27 named star pointers, many of which are flame-shaped with perforated bulbar bases, while four are positioned on rectangular mounts. The instrument includes seven plates providing various latitude settings, engraved with meridian lines, tropic lines, equator, almucantars, and hour lines.
The back of the mater features a zodiac scale, a calendar scale, and a double shadow square. An alidade with Gothic ends and two sights with double holes is present. The instrument displays evidence of modification, including a distinct, potentially later, script on the rete and specific plates, alongside areas of repair to the limb and rete.
Evidence at a glance
- Linked sources
- 1
- Photograph views
- 1
- Catalogue references
- 0
Counts describe this entry’s documentation, not authenticity, rarity or completeness. Photographs may show one specimen; check each caption and licence.
Technical characteristics
- Date
- circa 1260
- Type
- Iberian astrolabe
- Origin
- Hispano-Moorish
- Diameter
- 145 mm
- Suspension
- Ring, shackle, and swivel
- Place recorded
- Hispano-Moorish
Design
- Rete and Plates
- The astrolabe includes a Gothic-style rete containing 27 named star pointers. Most of these are flame-shaped with perforated bulbar bases, while four are situated on rectangular mounts atop the ecliptic. The ecliptic itself is divided by two degrees and numbered in increments of ten, connecting to the Capricorn band via two ties. The rete shows signs of re-engraving with a lighter, potentially later, script. Seven plates are provided, each featuring engraved east-west lines, meridian lines, tropic lines, and the equator. With few exceptions, these plates include unequal hour lines. Latitude settings range from 38 degrees to 58 degrees, with specific plates dedicated to locations such as Paris (Parisius) and Zaragoza (Cesar augusta). Plate 1b and 6b display the same later script observed on the rete, suggesting the instrument may have been adapted for a French owner.
- Visible features
- • Flame-shaped star pointers with perforated bulbar bases • Three-lobed throne with simple decoration • Horse-shaped wedge • Alidade features Gothic ends with two sights each having double holes
- Construction and Mater
- The mater of the astrolabe is composed of three riveted brass layers. The central layer is cast in one piece with a three-lobed throne that exhibits simple decoration. The limb is marked with two scales: one for hours, divided into 1-12 twice, and another for degrees, spanning 0 to 360 degrees. The limb shows evidence of alteration, specifically in the segment between 100 and 110 degrees, which has been replaced. The rear of the mater contains a zodiac scale with signs named in abbreviated forms, and an inner circle representing a calendar scale. The calendar is divided into days, with the 10th, 20th, and final days numbered. Additionally, the back features unequal hour lines numbered 1 to 6 and a double shadow square, designated as 'umbra recta' and 'umbra versa', divided into half-units and numbered by four.
- Accessories and Alterations
- The instrument is accompanied by a diametrical rule, an alidade, a pin, and a wedge. The diametrical rule is counterchanged and decorated with arabesque patterns, marked with numerals including 20, 30, and 90. The alidade is also counterchanged twice and features Gothic ends, with the two sights each containing double holes. The pin is adorned with concentric circles, while the wedge is shaped like a horse. Evidence suggests the astrolabe underwent modifications after its original manufacture. The rete and specific plates bear a distinct, lighter script compared to the bold Lombardic script found elsewhere on the instrument.
Identification
- Inventory number
- 37878
- Source note
- Facts transcribed from the linked source listing or collection record. Attribution and specifications are source-reported and have not been independently authenticated.
Catalogue references
No catalogue numbers recorded. Numbers are only published once transcribed from a verified edition of a standard catalogue — they are never inferred.
Research required
- Research required: The rete and specific plates may have been re-engraved or added for a later French owner
- Research required: The part of the limb between 100 and 110 degrees is a replacement