Quadrant signed A. D.
Record status
Individual type · partial
Period
1553
This brass quadrant, measuring 172 mm along the side, is dated 1553 and originates from Naples. It bears the signature monogram 'A. D.', identifying an instrument maker who remains unidentified.
The instrument features highly ornamental, foliate-patterned engraving across its arc. The front includes a zodiacal calendar, constellations, and various time-calculation markings. The reverse displays star declinations, scales for altimetry, longimetry, and degrees, along with a zodiacal calendar and a 24-hour scale. The instrument incorporates a list of 31 stars and a series of British place-names, including London, Bristol, York, Berwick, and Edinburgh.
An additional brass strip at the top edge suggests the former presence of a rete or sighting mechanism. The instrument is held by the Istituto e Museo di Storia della Scienza, Florence, and features an inscription regarding time and death signed 'T.R.'
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
- 1553
- Type
- Italian quadrant
- Maker
- A. D.
- Location
- Naples
- Dimensions
- 172 mm
- Place recorded
- Naples
- Motto signature
- T.R.
- Maker / attribution
- A. D.
Design
- Visible features
- • Brass construction with foliate tracery • Monogram 'A. D.' at the base • Inscribed British place names along the top edge • Symmetrical foliate decoration surrounding a central escutcheon
- Scales and Functions
- The front and reverse faces are densely populated with scales for varied timekeeping and astronomical calculations. The front contains lines for unequal, Italian, and 'hor? nostrates' hours, as well as a star list. A rectangular protractor scale is positioned around the projection, with a central hole intended for a thread cursor or brachiolus. The reverse side features a zodiacal calendar with Aries at 10 March, a 24-hour scale, and three main scales for Altimetria, Longometria, and Graduum, indicated by the letters 'A', 'L', and 'G'. The scales are visually differentiated by varied hatching techniques.
- Provenance and Attribution
- The instrument is catalogued under inventory number 2522 in the collection of the Istituto e Museo di Storia della Scienza in Florence. The monogram 'A. D.' appears on the instrument, though the identity of this maker is not definitively known. Researchers have noted the similarity of the work to that of Flemish-trained engravers working in Naples. The presence of British place-names suggests that the piece may have been commissioned as a presentation gift for a courtier accompanying Philip II of Spain to England for his marriage to Mary Tudor.
- Construction and Inscriptions
- The quadrant is fabricated from brass and measures 172 mm along its side. The circular arc is marked by elaborate foliate tracery and arabesque patterns. The upper portion of the instrument contains an inscription reading 'SYDERA VOLVV{N}TVR, FUGIVNT, HORA?, FVGIT VNA, VITA VELOX PERNIX SEQVITVR MORS, OMNIA STERNENS. + T + R +', which concerns the passage of time and the arrival of death. The upper edge features a riveted brass strip engraved with the latitudes of several British cities: London, Bristol, York, Berwick, and Edinburgh. The instrument also contains a list of 31 stars, some listed within a projection and others outside it.
Identification
- Reference
- 2522
- Inventory Number
- 2522
- 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 exact identity of the maker 'A. D.' remains unverified
- Research required: The purpose of the British place names is subject to historical hypothesis