Astrolabe, 1326
Record status
Individual type · partial
Period
1326
This brass astrolabe, measuring 132 mm in diameter, is dated 1326 and is widely associated with English origins. The mater is cut from a solid block with a crescent-shaped throne and a saddle-shaped shackle.
The rete features a Y-shape inside the ecliptic and incorporates 33 star pointers, ten of which are zoomorphic in the form of birds or a dog's head, with two depicted as human heads. The ecliptic displays the Latin names of the zodiacal signs. The reverse includes altitude scales, a circular solar scale, an eccentric calendrical scale, and a list of 46 saints and feasts. The plates are inscribed for various latitudes, including Oxford and Paris.
The alidade is counter-changed with two sighting vanes, accompanied by a long wedge featuring a horse head.
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
- 1326
- Type
- English astrolabe
- Maker
- Unsigned
- Diameter
- 132 mm
- Star Pointers
- 33
- Place recorded
- England
- Calendrical Scale
- Eccentric
Design
- Visible features
- • The rete includes zoomorphic star pointers featuring birds and a dog's head. • The circumferential frame displays a dragon's head and tail at the ends. • The wedge is designed with a small horse head at one end. • The mater is graduated in a clockwise direction from 0 to 360 degrees.
- Construction and Mater
- The astrolabe is constructed with a mater cut from a solid brass block. The frame is graduated clockwise from 0 to 360 degrees, with numbering by 5-degree increments and divisions to a single degree. The throne exhibits a crescent shape, complemented by a saddle-shaped shackle. The circumferential frame of the instrument is decorated with a dragon's head and tail at the respective ends. The interior of the mater is hollowed out, providing the base for the plates and the rete.
- Rete and Star Pointers
- The rete is characterized by a distinctive Y-shape situated within the ecliptic. It contains 33 identified stars, represented by pointers of varying designs. Ten of these star-pointers are zoomorphic, representing birds and a dog's head, while two are rendered as human heads. The ecliptic circle is marked with Latin names of the zodiacal signs. Each sign is divided into 30 degrees, with numbering occurring every 6 degrees and further subdivisions of 2 degrees.
- Plates and Reverse Markings
- The reverse of the instrument features four altitude scales and a circular solar scale marked with Latin names for zodiacal signs. An eccentric calendrical scale is positioned further inside, identifying months and specific feast days or saints. A pair of shadow scales is located in the lower half. The plates contain markings for almucantars, unequal hours, and the tropics. They are labeled for latitudes corresponding to locations including Jerusalem, Rome, Paris, and Oxford, providing geographical context for the instrument's use.
Identification
- Inventory Number
- MLA 1909,6-17.1
- 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 English origin is suggested by specific saint names and plate markers but remains an attribution.
- Research required: The specific function or meaning of the unusual prime vertical marking on the plates is not fully defined in the source.