Gilt brass quadrant with compass and scaphe sundial
Record status
Individual type · partial
Period
Later 16th century
This gilt brass quadrant, measuring 90 mm in radius, was made by Giovanni Battista Giusti in Florence during the later 16th century. It is a multifunctional instrument featuring a compass and a scaphe sundial on the front face, which is adorned with a relief mask at the center.
The opposite side includes a horary quadrant calibrated for a latitude of 42 degrees, corresponding to Rome, along with a magic square of three. The instrument is accompanied by its original red leather-lined velvet case. This object historically belonged to Pope Gregory XIII and is documented in the wardrobe inventory of Ferdinand I and the 1654 inventory of the Uffizi. The construction incorporates engraved scales, sundial diagrams for Italian hours, and scrolled foliate decoration, though the plumb line, cursors, needle, and glass are missing from the original assembly.
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
- Later 16th century
- Type
- Italian quadrant
- Maker
- Giovanni Battista Giusti
- Latitude
- 42 degrees
- Material
- Gilt brass
- Provenance
- Pope Gregory XIII
- Magic Square
- 3x3
- Place recorded
- Florence
- Maker / attribution
- Giovanni Battista Giusti
Design
- Visible features
- • Relief mask at the center of the front face • Magic square in the apex of the horary quadrant side • Hinged flap concealing the scaphe sundial • Scrolled foliate decoration in the instrument corners
- Historical Provenance
- The instrument is associated with Pope Gregory XIII. Following his ownership, it entered the Medici collections. It is identified in the wardrobe inventory of Ferdinand I as a gilt brass quadrant with an Italian clock that belonged to the Pope, stored in a leather case. A subsequent mention appears in the 1654 inventory of the Uffizi, which describes the item in detail, noting it as a gilt brass quadrant with a horizontal clock, a compass, and a solar clock, noting that the plumb line is missing. It remains preserved within its original red leather case lined with velvet.
- Condition and Completeness
- The auction description reports several losses affecting the instrument's original utility. The compass component is incomplete, lacking both its needle and the glass cover. Additionally, the instrument is missing its plumb line and cursor lines. The object retains its original red leather case, which is lined with velvet. The case features decorative elements including a six-roll frame, a central symmetrical leaf motif, and small five-petal flowers in the corners.
- Instrument Construction and Features
- The quadrant is constructed from gilt brass with a radius of 90 mm. One face features a horary quadrant graduated on the limb to 1 degree, marked for a latitude of 42 degrees. This face includes a diagram for an Italian hours dial and a magic square of three in the apex. The magic square sums to 15 in all directions and has a total of 45. The reverse side contains a compass and a scaphe sundial. The scaphe dial is protected by a small hinged cover, and a relief mask is positioned at the instrument's center. Parts of the surface are decorated with cross-hatched, scrolled foliate patterns, and the instrument includes sights, one with a pinnule, along its edge.
Identification
- Inventory Number
- 2525
- 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 needle and glass are missing from the compass
- Research required: The plumb and cursor lines are missing