Nocturnal
Record status
Individual type · partial
Period
16th century? (possibly 17th century)
This brass nocturnal, inventory number 37450 in the Museum of the History of Science, Oxford, is a circular time-measuring instrument measuring 87mm in length. It features an unsigned, unadorned design with a shaped and pierced handle for suspension.
The primary side consists of a base plate inscribed with a date scale, divided by month initials, and a rotating volvelle plate divided into 24 hours, marked with numerals 8 to 12 to 8. An index arm with a shaped tip is secured to the center by a pierced rivet. The reverse side includes an additional volvelle for calculating time in conjunction with a lunar sundial. The instrument lacks a maker's mark or date, and its attribution to the 16th century is considered speculative by the museum, noting it may date to the 17th century.
It is constructed entirely of brass.
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
- German nocturnal
- Length
- 87mm
- Material
- Brass
- Place recorded
- Germany
- Attributed Origin
- German
- Volvelle Side Configuration
- 12-hour scale divided twice
- Nocturnal Side Configuration
- Date scale with month initials
Design
- Visible features
- • Shaped and pierced suspension handle • Base plate with month initials on the perimeter • Rotating volvelle with 24-hour scale • Index arm with shaped, pierced tip
- Attribution and Status
- The instrument is unsigned and bears no maker's mark or specific identifying features that would link it to a particular workshop or historical period. The museum catalogue identifies it as being of German origin, though this is based on broader historical classifications. Dating the object is problematic, with the museum citing the 16th century as a speculative estimate. The entry notes that the simplicity of the design makes a 17th-century origin equally plausible. The lack of inscriptions or signatures leaves the precise temporal origin of the object open to interpretation.
- Construction and Design
- The nocturnal is a brass instrument measuring 87mm in length, featuring a central, pierced rivet that supports the pivoting components. The design is utilitarian, characterized by a shaped and pierced handle for portability and hanging. The primary surface holds the nocturnal functionality, while the reverse side supports an auxiliary volvelle. The primary plate is marked with a date scale containing initials for months, sub-divided into segments. The rotating volvelle plate displays a 24-hour cycle, using numerals from 8 to 12 and back to 8, with individual points marking the hour positions. Half-hour intervals are identified by arrows. An index arm featuring a distinct, shaped tip is attached to the central axis, facilitating the reading of time in relation to the stellar alignment indicated on the base plate.
- Functionality and Usage
- The instrument functions primarily to determine time at night using stellar movement. The nocturnal dial is configured to be used with the star positions relative to the date scale. The secondary side provides an alternative method for nocturnal timekeeping, specifically intended for use with a lunar sundial. The volvelle on the reverse of the plate requires the user to account for the shadow cast by the moon. By aligning this plate, the user can derive an approximate calculation of solar time, though the instrument cannot function independently for this specific lunar application.
Identification
- Inventory number
- 37450
- 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: Date is speculative and may be 16th or 17th century
- Research required: No manufacturer signature or maker attribution
- Research required: Requires external lunar sundial for full functionality of reverse side