Gilt Copper Quadrant
Record status
Individual type · partial
Period
After 1582
This gilt copper quadrant, measuring 150 mm in radius, is attributed to the maker Josua Habermel. The instrument is designed for the measurement of heights and distances, featuring a limb with dual scales.
The outer scale, titled 'Quadrans altitudinis', and the inner scale, 'Quadrans distantijs inseruiens', are both graduated from 0 to 90. The device utilizes an alidade pivoted at the apex, equipped with slit and half-solid sights, which align with corresponding fixed sights on the instrument's edge. A steel spring mechanism on the reverse, working with a curved arc, secures the alidade in place during observation. The reverse also contains a calendar table for determining the date of Easter, referencing the 1582 Gregorian calendar reform.
The quadrant is housed in a shaped wooden case, which is lined with leather, although the top cover of the box is missing.
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
- After 1582
- Type
- German quadrant
- Maker
- Josua Habermel
- Material
- Gilt copper
- Dimensions
- 150 mm radius
- Place recorded
- Germany
- Maker / attribution
- Josua Habermel
- Calendar Inscription
- Tabula generalis ad inueniendu diem paschatis et intercallum Iuxts Kalendarii reformatione
Design
- Visible features
- • Dual circular scales marked 0-90 on the limb • Pivoted alidade with fixed and movable sights • Steel spring mechanism mounted on the reverse • Leather-lined wooden storage case
- Measurement and Sight Systems
- The instrument features a primary limb divided into two distinct functional scales. The outer scale, labeled 'Quadrans altitudinis', and the inner scale, designated 'Quadrans distantijs inseruiens', both span 0 to 90 degrees. These scales utilize divisions of 10, with subdivisions at 5 and 1, incorporating alternate hatching for readability. The use of the instrument varies by scale, with the inner quadrant intended for use with the user's eye positioned at the apex, while the outer scale is operated with the eye placed at the limb. A central alidade, pivoted at the apex, is fitted with slit and half-solid sights designed to coordinate with two corresponding fixed sights positioned along the edge of the quadrant.
- Attribution and Calendar Function
- The reverse of the quadrant bears a comprehensive calendar table designed for calculating the date of Easter. The presence of the inscription referring to the calendar reform provides the terminus post quem for the object's manufacture, confirming it was created after 1582. Although the instrument does not bear a formal signature, it is attributed to Josua Habermel. This attribution is based on the technical quality of the engravings, the manufacturing techniques observed, and the overall accuracy of the instrument.
- Construction and Mechanical Features
- The device is constructed from gilt copper with a radius of 150 mm. A specific mechanical feature is the steel spring assembly attached to the reverse of the quadrant. This mechanism interacts with a quadrant-shaped arc positioned on top, which serves to restrain the alidade and maintain its position during specific measurements. The instrument includes an accessory for storage in the form of a shaped wooden box. This container is lined with leather. However, the assembly is incomplete as the top cover of the box is absent from the existing set.
Identification
- Inventory Number
- 2518
- 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 instrument is unsigned and attribution is based on stylistic analysis
- Research required: The original wooden lid for the case is missing