Horizontal dial for latitude 32° North
Record status
Individual type · partial
Period
17th century
Catalogued under ID AST0499 in the National Maritime Museum, Greenwich, this 17th-century horizontal dial is constructed from a rectangular brass plate measuring 9 by 57 by 82 mm.
Designed for latitude 32° North, the obverse surface is engraved with hour lines for Babylonian hours numbered in Indo-Arabic numerals, accompanied by a degree arc graduated in abjad numerals and a leaf-shaped index pointer. A round inset compass beneath glass features a blued arrow needle with an offset magnetic variation marking. The reverse side, as the museum reports, contains a three-column table detailing 41 Middle Eastern locations and their inhirafs.
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
- Type
- Horizontal dial / scientific instrument
- Date made
- 17th century
- Materials
- Brass ; Glass
- Museum ID
- AST0499
- Dimensions
- Overall: 9 x 57 x 82 mm
- Reverse inscription
- Table of 41 Middle Eastern places
- Latitude specification
- 32° North
Design
- Visible features
- • Rectangular brass plate engraved with radiating Babylonian hour lines numbered in Indo-Arabic script. • Graduated degree arc inscribed with abjad numerals located in the lower-left sector. • Movable leaf-shaped pointer positioned on the upper-left field. • Centrally placed upright brass gnomon pivot just above an inset round compass with a blued steel arrow needle beneath glass. • Perimeter border decorated with engraved quatrefoil cross and circular punch motifs.
- Construction and Physical Properties
- The instrument is a horizontal dial consisting of a rectangular brass plate measuring 9 by 57 by 82 mm. It is supported by four shaped corner brackets; the museum notes that one bracket is copper while the remaining three are brass. The device features an inset round compass protected by a glass plate. The compass assembly includes a blued, arrow-shaped needle resting on a brass pyramidal pivot and is secured to the plate with two screws visible on the reverse side.
- Documentation and Historical Context
- The museum documents a three-column table on the reverse side containing 41 Middle Eastern locations and their corresponding 'inhirafs'. The creator of the dial is unknown and it is dated to the 17th century. The museum references a similar example in the Whipple Museum (accession no. Wh: 1482).
- Obverse Engravings and Functionality
- The obverse includes a hinged pin gnomon and hour-lines for Babylonian hours, labeled in Indo-Arabic numerals. A degree arc, numbered in abjad numerals, is located in the top-right quadrant. A narrow, leaf-shaped index pointer is used to indicate the 'inhiraf'. The design displays four cardinal points and a meridian line providing the midday prayer curve (khatt zuhr). The edge of the plate is finished with a simple decorative border. The dial is designed for latitude 32° North and functions as a qibla pointer.
Identification
- Reference
- AST0499
- 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 reverse side containing the table of 41 locations and their inhirafs is documented by the museum but not visible in the provided image.
- Research required: Maker and exact place of production are unknown.